From d5421184271d764acea8a9b4265b842138bd21f3 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 6 Nov 2018 17:13:00 -0500
Subject: [PATCH 01/25] Add extract-meta.js.

---
 dash/extract-meta.js | 93 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 dash/extract-meta.js

diff --git a/dash/extract-meta.js b/dash/extract-meta.js
new file mode 100644
index 0000000000..8394bcfeed
--- /dev/null
+++ b/dash/extract-meta.js
@@ -0,0 +1,93 @@
+#!/usr/bin/env node
+
+const fs = require('fs');
+const path = require('path');
+const reactDocs = require('react-docgen');
+
+const componentPaths = process.argv.slice(2);
+if (!componentPaths.length) {
+    help();
+    process.exit(1);
+}
+
+const metadata = Object.create(null);
+componentPaths.forEach(componentPath =>
+    collectMetadataRecursively(componentPath)
+);
+writeOut(metadata);
+
+function help() {
+    console.error('usage: ');
+    console.error(
+        'extract-meta path/to/component(s) ' +
+            ' [path/to/more/component(s), ...] > metadata.json'
+    );
+}
+
+function writeError(msg, filePath) {
+    if (filePath) {
+        process.stderr.write(`Error with path ${filePath}`);
+    }
+
+    process.stderr.write(msg + '\n');
+    if (msg instanceof Error) {
+        process.stderr.write(msg.stack + '\n');
+    }
+}
+
+function checkWarn(name, value) {
+    if (value.length < 1) {
+        process.stderr.write(`\nDescription for ${name} is missing!\n`)
+    }
+}
+
+function docstringWarning(doc) {
+    checkWarn(doc.displayName, doc.description);
+
+    Object.entries(doc.props).forEach(
+        ([name, p]) => checkWarn(`${doc.displayName}.${name}`, p.description)
+    );
+}
+
+
+function parseFile(filepath) {
+    const urlpath = filepath.split(path.sep).join('/');
+    let src;
+
+    if (!['.jsx', '.js'].includes(path.extname(filepath))) {
+        return;
+    }
+
+    try {
+        src = fs.readFileSync(filepath);
+        const doc = metadata[urlpath] = reactDocs.parse(src);
+        docstringWarning(doc);
+    } catch (error) {
+        writeError(error, filepath);
+    }
+}
+
+function collectMetadataRecursively(componentPath) {
+    if (fs.lstatSync(componentPath).isDirectory()) {
+        let dirs;
+        try {
+            dirs = fs.readdirSync(componentPath);
+        } catch (error) {
+            writeError(error, componentPath);
+        }
+        dirs.forEach(filename => {
+            const filepath = path.join(componentPath, filename);
+            if (fs.lstatSync(filepath).isDirectory()) {
+                collectMetadataRecursively(filepath);
+            } else {
+                parseFile(filepath);
+            }
+        });
+    } else {
+        parseFile(componentPath);
+    }
+}
+
+function writeOut(result) {
+    console.log(JSON.stringify(result, '\t', 2));
+}

From 9863b9dfb81526133a696c1c1fe2cb1115ecb53c Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 6 Nov 2018 17:15:28 -0500
Subject: [PATCH 02/25] Combine extract-meta & component generation, wrap as
 cli.

---
 dash/development/component_generator.py | 62 +++++++++++++++++++++++++
 setup.py                                |  5 ++
 2 files changed, 67 insertions(+)
 create mode 100644 dash/development/component_generator.py

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
new file mode 100644
index 0000000000..76280ae9ae
--- /dev/null
+++ b/dash/development/component_generator.py
@@ -0,0 +1,62 @@
+from __future__ import print_function
+
+import json
+import sys
+import subprocess
+import shlex
+import os
+
+from .base_component import generate_class_file
+
+
+def generate_components(component_src, output_dir):
+    is_windows = sys.platform == 'win32'
+
+    extract_path = os.path.abspath(os.path.join(
+        os.path.dirname(__file__),
+        '..',
+        'extract-meta.js'
+    ))
+
+    os.environ['NODE_PATH'] = 'node_modules'
+    cmd = shlex.split('node {} {}'.format(extract_path, component_src),
+                      posix=not is_windows)
+
+    namespace = os.path.basename(output_dir)
+
+    proc = subprocess.Popen(cmd,
+                            stdout=subprocess.PIPE,
+                            stderr=subprocess.PIPE,
+                            shell=not is_windows)
+    out, err = proc.communicate()
+    status = proc.poll()
+
+    if err:
+        print(err.decode())
+
+    if not out:
+        print(
+            'Error generating {} metadata in {} (status={})'.format(
+                namespace, output_dir, status),
+            file=sys.stderr)
+        sys.exit(-1)
+    metadata = json.loads(out.decode())
+    for component_path, component_data in metadata.items():
+        name = component_path.split('/').pop().split('.')[0]
+        generate_class_file(
+            name,
+            component_data['props'],
+            component_data['description'],
+            namespace
+        )
+        print('Generated {}/{}.py'.format(namespace, name))
+
+
+def cli():
+    # pylint: disable=unbalanced-tuple-unpacking
+    src, out = sys.argv[1:]
+    generate_components(src, out)
+
+
+if __name__ == '__main__':
+    cli()
diff --git a/setup.py b/setup.py
index bee83d7eb7..9f22c8a4d1 100644
--- a/setup.py
+++ b/setup.py
@@ -22,6 +22,11 @@
         'plotly',
         'dash_renderer',
     ],
+    entry_points={
+        'console_scripts': [
+            'dash-generate-components = dash.development.component_generator:cli'
+        ]
+    },
     url='https://plot.ly/dash',
     classifiers=[
         'Development Status :: 5 - Production/Stable',

From 0c0d755798129a0a114136309f81c1168eee3f83 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 6 Nov 2018 17:24:54 -0500
Subject: [PATCH 03/25] Fix setup line len

---
 setup.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/setup.py b/setup.py
index 9f22c8a4d1..2182122ced 100644
--- a/setup.py
+++ b/setup.py
@@ -24,7 +24,8 @@
     ],
     entry_points={
         'console_scripts': [
-            'dash-generate-components = dash.development.component_generator:cli'
+            'dash-generate-components ='
+            ' dash.development.component_generator:cli'
         ]
     },
     url='https://plot.ly/dash',

From 1821b287a8c19a3f43011c2de157b37d20d6079a Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 6 Nov 2018 19:14:40 -0500
Subject: [PATCH 04/25] Add arguments validation.

---
 dash/development/component_generator.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index 76280ae9ae..4a8e3e9e6a 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -53,6 +53,14 @@ def generate_components(component_src, output_dir):
 
 
 def cli():
+    if len(sys.argv) != 3:
+        print(
+            'Invalid number of arguments'
+            ' expected 2 but got {}\n\n'
+            'Arguments: src output_directory'.format(len(sys.argv) - 1),
+            file=sys.stderr
+        )
+        sys.exit(-1)
     # pylint: disable=unbalanced-tuple-unpacking
     src, out = sys.argv[1:]
     generate_components(src, out)

From fde8d6c9cd40925f0c646df0d8a85c69f049fffe Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 6 Nov 2018 19:19:18 -0500
Subject: [PATCH 05/25] Add extract-meta to manifest.

---
 MANIFEST.in | 1 +
 1 file changed, 1 insertion(+)

diff --git a/MANIFEST.in b/MANIFEST.in
index af967cd137..caa2d28999 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,3 +1,4 @@
 include README.md
 include LICENSE
 include dash/favicon.ico
+include dash/extract-meta.js

From 087a63f8bfbc543b0fc0d872ee37d55ae211c2f9 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 6 Nov 2018 20:12:25 -0500
Subject: [PATCH 06/25] Print extract-meta errors to stderr

---
 dash/development/component_generator.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index 4a8e3e9e6a..465f50fdd0 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -32,14 +32,14 @@ def generate_components(component_src, output_dir):
     status = proc.poll()
 
     if err:
-        print(err.decode())
+        print(err.decode(), file=sys.stderr)
 
     if not out:
         print(
             'Error generating {} metadata in {} (status={})'.format(
                 namespace, output_dir, status),
             file=sys.stderr)
-        sys.exit(-1)
+        sys.exit(1)
     metadata = json.loads(out.decode())
     for component_path, component_data in metadata.items():
         name = component_path.split('/').pop().split('.')[0]
@@ -60,7 +60,7 @@ def cli():
             'Arguments: src output_directory'.format(len(sys.argv) - 1),
             file=sys.stderr
         )
-        sys.exit(-1)
+        sys.exit(1)
     # pylint: disable=unbalanced-tuple-unpacking
     src, out = sys.argv[1:]
     generate_components(src, out)

From 1e5adce2132c0548daec2a546b16fb5a35ea8af7 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 6 Nov 2018 20:18:44 -0500
Subject: [PATCH 07/25] Dump metadata.json

---
 dash/development/component_generator.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index 465f50fdd0..3c13c11910 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -40,9 +40,11 @@ def generate_components(component_src, output_dir):
                 namespace, output_dir, status),
             file=sys.stderr)
         sys.exit(1)
+
     metadata = json.loads(out.decode())
+
     for component_path, component_data in metadata.items():
-        name = component_path.split('/').pop().split('.')[0]
+        name = component_path.split('/')[-1].split('.')[0]
         generate_class_file(
             name,
             component_data['props'],
@@ -51,6 +53,9 @@ def generate_components(component_src, output_dir):
         )
         print('Generated {}/{}.py'.format(namespace, name))
 
+    with open(os.path.join(output_dir, 'metadata.json'), 'w') as f:
+        json.dump(metadata, f)
+
 
 def cli():
     if len(sys.argv) != 3:

From 726623db724abeb907ec1e2eef6f73b8d9fc8f2c Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 6 Nov 2018 22:01:04 -0500
Subject: [PATCH 08/25] Add _imports_.py generation.

---
 dash/development/component_generator.py | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index 3c13c11910..e4d56c33b9 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -5,10 +5,12 @@
 import subprocess
 import shlex
 import os
+import textwrap
 
 from .base_component import generate_class_file
 
 
+# pylint: disable=too-many-locals
 def generate_components(component_src, output_dir):
     is_windows = sys.platform == 'win32'
 
@@ -43,8 +45,11 @@ def generate_components(component_src, output_dir):
 
     metadata = json.loads(out.decode())
 
+    components = []
+
     for component_path, component_data in metadata.items():
         name = component_path.split('/')[-1].split('.')[0]
+        components.append(name)
         generate_class_file(
             name,
             component_data['props'],
@@ -56,6 +61,20 @@ def generate_components(component_src, output_dir):
     with open(os.path.join(output_dir, 'metadata.json'), 'w') as f:
         json.dump(metadata, f)
 
+    with open(os.path.join(output_dir, '_imports_.py'), 'w') as f:
+        f.write(textwrap.dedent(
+            '''
+            {}
+
+            __all__ = [
+            {}
+            ]
+            '''.format(
+                '\n'.join('from {0} import {0}'.format(x) for x in components),
+                ',\n'.join('    "{}"'.format(x) for x in components)
+            )
+        ))
+
 
 def cli():
     if len(sys.argv) != 3:

From 1bbd7fbe7fd00e080976a19b76e2d3262fba95c5 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Wed, 7 Nov 2018 16:33:42 -0500
Subject: [PATCH 09/25] Strip first newline from `_imports_.py`.

---
 dash/development/component_generator.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index e4d56c33b9..53f77e3638 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -73,7 +73,7 @@ def generate_components(component_src, output_dir):
                 '\n'.join('from {0} import {0}'.format(x) for x in components),
                 ',\n'.join('    "{}"'.format(x) for x in components)
             )
-        ))
+        ).lstrip())
 
 
 def cli():

From 98811a141b47bdc2b192b840ca9b8d78c8e711e3 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Wed, 7 Nov 2018 18:18:51 -0500
Subject: [PATCH 10/25] Change output_dir to project_shortname.

---
 dash/development/component_generator.py | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index 53f77e3638..a3c6027262 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -11,7 +11,7 @@
 
 
 # pylint: disable=too-many-locals
-def generate_components(component_src, output_dir):
+def generate_components(component_src, project_shortname):
     is_windows = sys.platform == 'win32'
 
     extract_path = os.path.abspath(os.path.join(
@@ -24,8 +24,6 @@ def generate_components(component_src, output_dir):
     cmd = shlex.split('node {} {}'.format(extract_path, component_src),
                       posix=not is_windows)
 
-    namespace = os.path.basename(output_dir)
-
     proc = subprocess.Popen(cmd,
                             stdout=subprocess.PIPE,
                             stderr=subprocess.PIPE,
@@ -38,8 +36,8 @@ def generate_components(component_src, output_dir):
 
     if not out:
         print(
-            'Error generating {} metadata in {} (status={})'.format(
-                namespace, output_dir, status),
+            'Error generating metadata in {} (status={})'.format(
+                project_shortname, status),
             file=sys.stderr)
         sys.exit(1)
 
@@ -54,14 +52,14 @@ def generate_components(component_src, output_dir):
             name,
             component_data['props'],
             component_data['description'],
-            namespace
+            project_shortname
         )
-        print('Generated {}/{}.py'.format(namespace, name))
+        print('Generated {}/{}.py'.format(project_shortname, name))
 
-    with open(os.path.join(output_dir, 'metadata.json'), 'w') as f:
+    with open(os.path.join(project_shortname, 'metadata.json'), 'w') as f:
         json.dump(metadata, f)
 
-    with open(os.path.join(output_dir, '_imports_.py'), 'w') as f:
+    with open(os.path.join(project_shortname, '_imports_.py'), 'w') as f:
         f.write(textwrap.dedent(
             '''
             {}
@@ -81,13 +79,13 @@ def cli():
         print(
             'Invalid number of arguments'
             ' expected 2 but got {}\n\n'
-            'Arguments: src output_directory'.format(len(sys.argv) - 1),
+            'Arguments: src project_shortname'.format(len(sys.argv) - 1),
             file=sys.stderr
         )
         sys.exit(1)
     # pylint: disable=unbalanced-tuple-unpacking
-    src, out = sys.argv[1:]
-    generate_components(src, out)
+    src, project_shortname = sys.argv[1:]
+    generate_components(src, project_shortname)
 
 
 if __name__ == '__main__':

From 757327ac8897efcd8fbb22f6da2c34ea2ee33b9b Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Mon, 12 Nov 2018 17:33:03 -0500
Subject: [PATCH 11/25] Fix shell is_windows.

---
 dash/development/component_generator.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index a3c6027262..6e292269e3 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -27,7 +27,7 @@ def generate_components(component_src, project_shortname):
     proc = subprocess.Popen(cmd,
                             stdout=subprocess.PIPE,
                             stderr=subprocess.PIPE,
-                            shell=not is_windows)
+                            shell=is_windows)
     out, err = proc.communicate()
     status = proc.poll()
 

From b5f619947bb4a1006529c53b6f4094cd86f497d6 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Mon, 12 Nov 2018 19:17:41 -0500
Subject: [PATCH 12/25] Relative import the components

---
 dash/development/component_generator.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index 6e292269e3..79cec46df1 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -68,7 +68,8 @@ def generate_components(component_src, project_shortname):
             {}
             ]
             '''.format(
-                '\n'.join('from {0} import {0}'.format(x) for x in components),
+                '\n'.join(
+                    'from .{0} import {0}'.format(x) for x in components),
                 ',\n'.join('    "{}"'.format(x) for x in components)
             )
         ).lstrip())

From b8339d1f6f0562db76f04458c1fc39c680613f25 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 13 Nov 2018 13:31:40 -0500
Subject: [PATCH 13/25] Rename name->component_name

---
 dash/development/component_generator.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index 79cec46df1..ad6dd09435 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -46,15 +46,15 @@ def generate_components(component_src, project_shortname):
     components = []
 
     for component_path, component_data in metadata.items():
-        name = component_path.split('/')[-1].split('.')[0]
-        components.append(name)
+        component_name = component_path.split('/')[-1].split('.')[0]
+        components.append(component_name)
         generate_class_file(
-            name,
+            component_name,
             component_data['props'],
             component_data['description'],
             project_shortname
         )
-        print('Generated {}/{}.py'.format(project_shortname, name))
+        print('Generated {}/{}.py'.format(project_shortname, component_name))
 
     with open(os.path.join(project_shortname, 'metadata.json'), 'w') as f:
         json.dump(metadata, f)

From 68087cf811fe6beb1586906817fe30f60fe1b1d5 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 13 Nov 2018 13:33:48 -0500
Subject: [PATCH 14/25] Move generated print to generate_class_file.

---
 dash/development/base_component.py      | 2 ++
 dash/development/component_generator.py | 1 -
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/dash/development/base_component.py b/dash/development/base_component.py
index 789253a3f2..bff5864fc2 100644
--- a/dash/development/base_component.py
+++ b/dash/development/base_component.py
@@ -465,6 +465,8 @@ def generate_class_file(typename, props, description, namespace):
     with open(file_path, 'w') as f:
         f.write(import_string)
         f.write(class_string)
+        
+    print('Generated {}'.format(file_name))
 
 
 # pylint: disable=unused-argument
diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index ad6dd09435..948a826eb9 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -54,7 +54,6 @@ def generate_components(component_src, project_shortname):
             component_data['description'],
             project_shortname
         )
-        print('Generated {}/{}.py'.format(project_shortname, component_name))
 
     with open(os.path.join(project_shortname, 'metadata.json'), 'w') as f:
         json.dump(metadata, f)

From b3070dcd535c617b50b684ac57f632c163c16e6c Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 13 Nov 2018 13:39:14 -0500
Subject: [PATCH 15/25] :camel: generate_imports

---
 dash/development/base_component.py      |  2 +-
 dash/development/component_generator.py | 17 ++-----------
 dash/development/component_loader.py    | 34 +++++++++++++++++--------
 3 files changed, 26 insertions(+), 27 deletions(-)

diff --git a/dash/development/base_component.py b/dash/development/base_component.py
index bff5864fc2..10db6e0f11 100644
--- a/dash/development/base_component.py
+++ b/dash/development/base_component.py
@@ -465,7 +465,7 @@ def generate_class_file(typename, props, description, namespace):
     with open(file_path, 'w') as f:
         f.write(import_string)
         f.write(class_string)
-        
+
     print('Generated {}'.format(file_name))
 
 
diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index 948a826eb9..941b91eaf9 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -5,8 +5,8 @@
 import subprocess
 import shlex
 import os
-import textwrap
 
+from dash.development.component_loader import generate_imports
 from .base_component import generate_class_file
 
 
@@ -58,20 +58,7 @@ def generate_components(component_src, project_shortname):
     with open(os.path.join(project_shortname, 'metadata.json'), 'w') as f:
         json.dump(metadata, f)
 
-    with open(os.path.join(project_shortname, '_imports_.py'), 'w') as f:
-        f.write(textwrap.dedent(
-            '''
-            {}
-
-            __all__ = [
-            {}
-            ]
-            '''.format(
-                '\n'.join(
-                    'from .{0} import {0}'.format(x) for x in components),
-                ',\n'.join('    "{}"'.format(x) for x in components)
-            )
-        ).lstrip())
+    generate_imports(project_shortname, components)
 
 
 def cli():
diff --git a/dash/development/component_loader.py b/dash/development/component_loader.py
index 2b5e70b10f..6029e1950f 100644
--- a/dash/development/component_loader.py
+++ b/dash/development/component_loader.py
@@ -1,6 +1,8 @@
 import collections
 import json
 import os
+import textwrap
+
 from .base_component import generate_class
 from .base_component import generate_class_file
 from .base_component import ComponentRegistry
@@ -16,6 +18,23 @@ def _get_metadata(metadata_path):
     return data
 
 
+def generate_imports(project_shortname, components):
+    with open(os.path.join(project_shortname, '_imports_.py'), 'w') as f:
+        f.write(textwrap.dedent(
+            '''
+            {}
+
+            __all__ = [
+            {}
+            ]
+            '''.format(
+                '\n'.join(
+                    'from .{0} import {0}'.format(x) for x in components),
+                ',\n'.join('    "{}"'.format(x) for x in components)
+            )
+        ).lstrip())
+
+
 def load_components(metadata_path,
                     namespace='default_namespace'):
     """Load React component metadata into a format Dash can parse.
@@ -81,6 +100,8 @@ def generate_classes(namespace, metadata_path='lib/metadata.json'):
     if os.path.exists(imports_path):
         os.remove(imports_path)
 
+    components = []
+
     # Iterate over each property name (which is a path to the component)
     for componentPath in data:
         componentData = data[componentPath]
@@ -97,16 +118,7 @@ def generate_classes(namespace, metadata_path='lib/metadata.json'):
             componentData['description'],
             namespace
         )
-
-        # Add an import statement for this component
-        with open(imports_path, 'a') as f:
-            f.write('from .{0:s} import {0:s}\n'.format(name))
+        components.append(name)
 
     # Add the __all__ value so we can import * from _imports_
-    all_imports = [p.split('/').pop().split('.')[0] for p in data]
-    with open(imports_path, 'a') as f:
-        array_string = '[\n'
-        for a in all_imports:
-            array_string += '    "{:s}",\n'.format(a)
-        array_string += ']\n'
-        f.write('\n\n__all__ = {:s}'.format(array_string))
+    generate_imports(namespace, components)

From 474f99539d46562f246d9f8c351cded1c23b5a40 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 13 Nov 2018 13:52:18 -0500
Subject: [PATCH 16/25] Disable superflous-parens pylint.

---
 .pylintrc | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/.pylintrc b/.pylintrc
index fcf0968f10..a9688e4e7a 100644
--- a/.pylintrc
+++ b/.pylintrc
@@ -58,7 +58,9 @@ disable=fixme,
         missing-docstring,
         invalid-name,
         too-many-lines,
-        old-style-class
+        old-style-class,
+        superfluous-parens
+
 # Enable the message, report, category or checker with the given id(s). You can
 # either give multiple identifier separated by comma (,) or put this option
 # multiple time (only on the command line, not in the configuration file where

From 414ac623c34bea634800ba1bde69f0828ea9d5c9 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 13 Nov 2018 14:15:53 -0500
Subject: [PATCH 17/25] relative import.

---
 dash/development/component_generator.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index 941b91eaf9..008af05ea5 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -6,7 +6,7 @@
 import shlex
 import os
 
-from dash.development.component_loader import generate_imports
+from .component_loader import generate_imports
 from .base_component import generate_class_file
 
 

From 25a8e94634bab006c8f7fd177fbde78a4913e86e Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 13 Nov 2018 19:27:42 -0500
Subject: [PATCH 18/25] :camel: generate classes files loop.

---
 dash/development/component_generator.py | 18 ++++--------
 dash/development/component_loader.py    | 37 ++++++++++++-------------
 2 files changed, 24 insertions(+), 31 deletions(-)

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index 008af05ea5..c7072d0690 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -6,7 +6,7 @@
 import shlex
 import os
 
-from .component_loader import generate_imports
+from .component_loader import generate_imports, generate_classes_files
 from .base_component import generate_class_file
 
 
@@ -43,17 +43,11 @@ def generate_components(component_src, project_shortname):
 
     metadata = json.loads(out.decode())
 
-    components = []
-
-    for component_path, component_data in metadata.items():
-        component_name = component_path.split('/')[-1].split('.')[0]
-        components.append(component_name)
-        generate_class_file(
-            component_name,
-            component_data['props'],
-            component_data['description'],
-            project_shortname
-        )
+    components = generate_classes_files(
+        project_shortname,
+        metadata,
+        generate_class_file
+    )
 
     with open(os.path.join(project_shortname, 'metadata.json'), 'w') as f:
         json.dump(metadata, f)
diff --git a/dash/development/component_loader.py b/dash/development/component_loader.py
index 6029e1950f..a055230271 100644
--- a/dash/development/component_loader.py
+++ b/dash/development/component_loader.py
@@ -78,6 +78,23 @@ def load_components(metadata_path,
     return components
 
 
+def generate_classes_files(project_shortname, metadata, *component_generators):
+    components = []
+    for component_path, component_data in metadata.items():
+        component_name = component_path.split('/')[-1].split('.')[0]
+        components.append(component_name)
+
+        for generator in component_generators:
+            generator(
+                component_name,
+                component_data['props'],
+                component_data['description'],
+                project_shortname
+            )
+
+    return components
+
+
 def generate_classes(namespace, metadata_path='lib/metadata.json'):
     """Load React component metadata into a format Dash can parse,
     then create python class files.
@@ -100,25 +117,7 @@ def generate_classes(namespace, metadata_path='lib/metadata.json'):
     if os.path.exists(imports_path):
         os.remove(imports_path)
 
-    components = []
-
-    # Iterate over each property name (which is a path to the component)
-    for componentPath in data:
-        componentData = data[componentPath]
-
-        # Extract component name from path
-        # e.g. src/components/MyControl.react.js
-        # TODO Make more robust - some folks will write .jsx and others
-        # will be on windows. Unfortunately react-docgen doesn't include
-        # the name of the component atm.
-        name = componentPath.split('/').pop().split('.')[0]
-        generate_class_file(
-            name,
-            componentData['props'],
-            componentData['description'],
-            namespace
-        )
-        components.append(name)
+    components = generate_classes_files(namespace, data, generate_class_file)
 
     # Add the __all__ value so we can import * from _imports_
     generate_imports(namespace, components)

From c642b84f5e0fa3cc44296d1e2797350dc1c87648 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 13 Nov 2018 19:38:48 -0500
Subject: [PATCH 19/25] :feet: Move generate imports/files methods to
 base_components.

---
 dash/development/base_component.py      | 36 ++++++++++++++++++++++++
 dash/development/component_generator.py |  3 +-
 dash/development/component_loader.py    | 37 ++-----------------------
 3 files changed, 40 insertions(+), 36 deletions(-)

diff --git a/dash/development/base_component.py b/dash/development/base_component.py
index 10db6e0f11..af589f45a7 100644
--- a/dash/development/base_component.py
+++ b/dash/development/base_component.py
@@ -4,6 +4,8 @@
 import inspect
 import abc
 import sys
+import textwrap
+
 import six
 
 from ._all_keywords import kwlist
@@ -884,3 +886,37 @@ def js_to_py_type(type_object, is_flow_type=False, indent_num=0):
         # All other types
         return js_to_py_types[js_type_name]()
     return ''
+
+
+def generate_imports(project_shortname, components):
+    with open(os.path.join(project_shortname, '_imports_.py'), 'w') as f:
+        f.write(textwrap.dedent(
+            '''
+            {}
+
+            __all__ = [
+            {}
+            ]
+            '''.format(
+                '\n'.join(
+                    'from .{0} import {0}'.format(x) for x in components),
+                ',\n'.join('    "{}"'.format(x) for x in components)
+            )
+        ).lstrip())
+
+
+def generate_classes_files(project_shortname, metadata, *component_generators):
+    components = []
+    for component_path, component_data in metadata.items():
+        component_name = component_path.split('/')[-1].split('.')[0]
+        components.append(component_name)
+
+        for generator in component_generators:
+            generator(
+                component_name,
+                component_data['props'],
+                component_data['description'],
+                project_shortname
+            )
+
+    return components
diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index c7072d0690..a06cd7ce40 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -6,8 +6,9 @@
 import shlex
 import os
 
-from .component_loader import generate_imports, generate_classes_files
 from .base_component import generate_class_file
+from .base_component import generate_imports
+from .base_component import generate_classes_files
 
 
 # pylint: disable=too-many-locals
diff --git a/dash/development/component_loader.py b/dash/development/component_loader.py
index a055230271..99a451fd29 100644
--- a/dash/development/component_loader.py
+++ b/dash/development/component_loader.py
@@ -1,8 +1,9 @@
 import collections
 import json
 import os
-import textwrap
 
+from .base_component import generate_imports
+from .base_component import generate_classes_files
 from .base_component import generate_class
 from .base_component import generate_class_file
 from .base_component import ComponentRegistry
@@ -18,23 +19,6 @@ def _get_metadata(metadata_path):
     return data
 
 
-def generate_imports(project_shortname, components):
-    with open(os.path.join(project_shortname, '_imports_.py'), 'w') as f:
-        f.write(textwrap.dedent(
-            '''
-            {}
-
-            __all__ = [
-            {}
-            ]
-            '''.format(
-                '\n'.join(
-                    'from .{0} import {0}'.format(x) for x in components),
-                ',\n'.join('    "{}"'.format(x) for x in components)
-            )
-        ).lstrip())
-
-
 def load_components(metadata_path,
                     namespace='default_namespace'):
     """Load React component metadata into a format Dash can parse.
@@ -78,23 +62,6 @@ def load_components(metadata_path,
     return components
 
 
-def generate_classes_files(project_shortname, metadata, *component_generators):
-    components = []
-    for component_path, component_data in metadata.items():
-        component_name = component_path.split('/')[-1].split('.')[0]
-        components.append(component_name)
-
-        for generator in component_generators:
-            generator(
-                component_name,
-                component_data['props'],
-                component_data['description'],
-                project_shortname
-            )
-
-    return components
-
-
 def generate_classes(namespace, metadata_path='lib/metadata.json'):
     """Load React component metadata into a format Dash can parse,
     then create python class files.

From b53f54a0439eceba3ee3ba7db69d763e73f91dc5 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Tue, 20 Nov 2018 16:11:08 -0500
Subject: [PATCH 20/25] Proper cli with argparse.

---
 dash/development/component_generator.py | 31 ++++++++++++++++---------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index a06cd7ce40..3f51b7c394 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -5,12 +5,18 @@
 import subprocess
 import shlex
 import os
+import argparse
 
 from .base_component import generate_class_file
 from .base_component import generate_imports
 from .base_component import generate_classes_files
 
 
+class _CombinedFormatter(argparse.ArgumentDefaultsHelpFormatter,
+                         argparse.RawDescriptionHelpFormatter):
+    pass
+
+
 # pylint: disable=too-many-locals
 def generate_components(component_src, project_shortname):
     is_windows = sys.platform == 'win32'
@@ -57,17 +63,20 @@ def generate_components(component_src, project_shortname):
 
 
 def cli():
-    if len(sys.argv) != 3:
-        print(
-            'Invalid number of arguments'
-            ' expected 2 but got {}\n\n'
-            'Arguments: src project_shortname'.format(len(sys.argv) - 1),
-            file=sys.stderr
-        )
-        sys.exit(1)
-    # pylint: disable=unbalanced-tuple-unpacking
-    src, project_shortname = sys.argv[1:]
-    generate_components(src, project_shortname)
+    parser = argparse.ArgumentParser(
+        prog='dash-generate-components',
+        formatter_class=_CombinedFormatter,
+        description='Generate dash components by extracting the metadata '
+        'using react-docgen. Then map the metadata to python classes.'
+    )
+    parser.add_argument('src', help='React components source directory.')
+    parser.add_argument(
+        'project_shortname',
+        help='Name of the project to export the classes files.'
+    )
+
+    args = parser.parse_args()
+    generate_components(args.src, args.project_shortname)
 
 
 if __name__ == '__main__':

From a3d5ae20293cd3dbdb881e26b7e6db3da2d51fcf Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Wed, 21 Nov 2018 12:10:35 -0500
Subject: [PATCH 21/25] Copy package.json, take the output filename as option.

---
 dash/development/component_generator.py | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index 3f51b7c394..ad7ad62b2f 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -6,6 +6,7 @@
 import shlex
 import os
 import argparse
+import shutil
 
 from .base_component import generate_class_file
 from .base_component import generate_imports
@@ -18,7 +19,8 @@ class _CombinedFormatter(argparse.ArgumentDefaultsHelpFormatter,
 
 
 # pylint: disable=too-many-locals
-def generate_components(component_src, project_shortname):
+def generate_components(component_src, project_shortname,
+                        package_info_filename='package.json'):
     is_windows = sys.platform == 'win32'
 
     extract_path = os.path.abspath(os.path.join(
@@ -31,6 +33,9 @@ def generate_components(component_src, project_shortname):
     cmd = shlex.split('node {} {}'.format(extract_path, component_src),
                       posix=not is_windows)
 
+    shutil.copyfile('package.json',
+                    os.path.join(project_shortname,package_info_filename))
+
     proc = subprocess.Popen(cmd,
                             stdout=subprocess.PIPE,
                             stderr=subprocess.PIPE,
@@ -74,9 +79,15 @@ def cli():
         'project_shortname',
         help='Name of the project to export the classes files.'
     )
+    parser.add_argument(
+        '-p', '--package-info-filename',
+        default='package.json',
+        help='The filename of the copied `package.json` to `project_shortname`'
+    )
 
     args = parser.parse_args()
-    generate_components(args.src, args.project_shortname)
+    generate_components(args.src, args.project_shortname,
+                        package_info_filename=args.package_info_filename)
 
 
 if __name__ == '__main__':

From 52a56f9f8636cecf2301c3b63c73119c7e95090d Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Wed, 21 Nov 2018 12:15:02 -0500
Subject: [PATCH 22/25] :name_badge: src -> components_sources

---
 dash/development/component_generator.py | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index ad7ad62b2f..04649a691e 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -19,7 +19,7 @@ class _CombinedFormatter(argparse.ArgumentDefaultsHelpFormatter,
 
 
 # pylint: disable=too-many-locals
-def generate_components(component_src, project_shortname,
+def generate_components(components_source, project_shortname,
                         package_info_filename='package.json'):
     is_windows = sys.platform == 'win32'
 
@@ -30,11 +30,11 @@ def generate_components(component_src, project_shortname,
     ))
 
     os.environ['NODE_PATH'] = 'node_modules'
-    cmd = shlex.split('node {} {}'.format(extract_path, component_src),
+    cmd = shlex.split('node {} {}'.format(extract_path, components_source),
                       posix=not is_windows)
 
     shutil.copyfile('package.json',
-                    os.path.join(project_shortname,package_info_filename))
+                    os.path.join(project_shortname, package_info_filename))
 
     proc = subprocess.Popen(cmd,
                             stdout=subprocess.PIPE,
@@ -74,7 +74,8 @@ def cli():
         description='Generate dash components by extracting the metadata '
         'using react-docgen. Then map the metadata to python classes.'
     )
-    parser.add_argument('src', help='React components source directory.')
+    parser.add_argument('components_source',
+                        help='React components source directory.')
     parser.add_argument(
         'project_shortname',
         help='Name of the project to export the classes files.'
@@ -86,7 +87,7 @@ def cli():
     )
 
     args = parser.parse_args()
-    generate_components(args.src, args.project_shortname,
+    generate_components(args.components_source, args.project_shortname,
                         package_info_filename=args.package_info_filename)
 
 

From 6d8e6b7f96720884aaaf0df8418e3dc0bf1b37c0 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Mon, 26 Nov 2018 16:16:28 -0500
Subject: [PATCH 23/25] Use pkg_resources to make the extract-meta.js path.

---
 dash/development/component_generator.py | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index 04649a691e..6c2f9bd842 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -7,6 +7,8 @@
 import os
 import argparse
 import shutil
+import pkg_resources
+
 
 from .base_component import generate_class_file
 from .base_component import generate_imports
@@ -23,11 +25,7 @@ def generate_components(components_source, project_shortname,
                         package_info_filename='package.json'):
     is_windows = sys.platform == 'win32'
 
-    extract_path = os.path.abspath(os.path.join(
-        os.path.dirname(__file__),
-        '..',
-        'extract-meta.js'
-    ))
+    extract_path = pkg_resources.resource_filename('dash', 'extract-meta.js')
 
     os.environ['NODE_PATH'] = 'node_modules'
     cmd = shlex.split('node {} {}'.format(extract_path, components_source),

From 4878245f2ead071bb5e78364be5c07c94e598b60 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Mon, 26 Nov 2018 16:58:23 -0500
Subject: [PATCH 24/25] :feet: Move component generation code to
 _py_components_generation.py

---
 dash/development/_py_components_generation.py | 615 ++++++++++++++++
 dash/development/base_component.py            | 666 +-----------------
 dash/development/component_generator.py       |   8 +-
 dash/development/component_loader.py          |  10 +-
 tests/development/test_base_component.py      |  11 +-
 tests/development/test_component_loader.py    |   2 +-
 tests/test_resources.py                       |   2 +-
 7 files changed, 656 insertions(+), 658 deletions(-)
 create mode 100644 dash/development/_py_components_generation.py

diff --git a/dash/development/_py_components_generation.py b/dash/development/_py_components_generation.py
new file mode 100644
index 0000000000..ba17ccd84d
--- /dev/null
+++ b/dash/development/_py_components_generation.py
@@ -0,0 +1,615 @@
+import collections
+import copy
+import os
+import textwrap
+
+from dash.development.base_component import _explicitize_args
+from ._all_keywords import kwlist
+from .base_component import Component
+
+
+# pylint: disable=unused-argument
+def generate_class_string(typename, props, description, namespace):
+    """
+    Dynamically generate class strings to have nicely formatted docstrings,
+    keyword arguments, and repr
+
+    Inspired by http://jameso.be/2013/08/06/namedtuple.html
+
+    Parameters
+    ----------
+    typename
+    props
+    description
+    namespace
+
+    Returns
+    -------
+    string
+
+    """
+    # TODO _prop_names, _type, _namespace, available_events,
+    # and available_properties
+    # can be modified by a Dash JS developer via setattr
+    # TODO - Tab out the repr for the repr of these components to make it
+    # look more like a hierarchical tree
+    # TODO - Include "description" "defaultValue" in the repr and docstring
+    #
+    # TODO - Handle "required"
+    #
+    # TODO - How to handle user-given `null` values? I want to include
+    # an expanded docstring like Dropdown(value=None, id=None)
+    # but by templating in those None values, I have no way of knowing
+    # whether a property is None because the user explicitly wanted
+    # it to be `null` or whether that was just the default value.
+    # The solution might be to deal with default values better although
+    # not all component authors will supply those.
+    c = '''class {typename}(Component):
+    """{docstring}"""
+    @_explicitize_args
+    def __init__(self, {default_argtext}):
+        self._prop_names = {list_of_valid_keys}
+        self._type = '{typename}'
+        self._namespace = '{namespace}'
+        self._valid_wildcard_attributes =\
+            {list_of_valid_wildcard_attr_prefixes}
+        self.available_events = {events}
+        self.available_properties = {list_of_valid_keys}
+        self.available_wildcard_properties =\
+            {list_of_valid_wildcard_attr_prefixes}
+
+        _explicit_args = kwargs.pop('_explicit_args')
+        _locals = locals()
+        _locals.update(kwargs)  # For wildcard attrs
+        args = {{k: _locals[k] for k in _explicit_args if k != 'children'}}
+
+        for k in {required_args}:
+            if k not in args:
+                raise TypeError(
+                    'Required argument `' + k + '` was not specified.')
+        super({typename}, self).__init__({argtext})
+
+    def __repr__(self):
+        if(any(getattr(self, c, None) is not None
+               for c in self._prop_names
+               if c is not self._prop_names[0])
+           or any(getattr(self, c, None) is not None
+                  for c in self.__dict__.keys()
+                  if any(c.startswith(wc_attr)
+                  for wc_attr in self._valid_wildcard_attributes))):
+            props_string = ', '.join([c+'='+repr(getattr(self, c, None))
+                                      for c in self._prop_names
+                                      if getattr(self, c, None) is not None])
+            wilds_string = ', '.join([c+'='+repr(getattr(self, c, None))
+                                      for c in self.__dict__.keys()
+                                      if any([c.startswith(wc_attr)
+                                      for wc_attr in
+                                      self._valid_wildcard_attributes])])
+            return ('{typename}(' + props_string +
+                   (', ' + wilds_string if wilds_string != '' else '') + ')')
+        else:
+            return (
+                '{typename}(' +
+                repr(getattr(self, self._prop_names[0], None)) + ')')
+'''
+
+    filtered_props = reorder_props(filter_props(props))
+    # pylint: disable=unused-variable
+    list_of_valid_wildcard_attr_prefixes = repr(parse_wildcards(props))
+    # pylint: disable=unused-variable
+    list_of_valid_keys = repr(list(map(str, filtered_props.keys())))
+    # pylint: disable=unused-variable
+    docstring = create_docstring(
+        component_name=typename,
+        props=filtered_props,
+        events=parse_events(props),
+        description=description).replace('\r\n', '\n')
+
+    # pylint: disable=unused-variable
+    events = '[' + ', '.join(parse_events(props)) + ']'
+    prop_keys = list(props.keys())
+    if 'children' in props:
+        prop_keys.remove('children')
+        default_argtext = "children=None, "
+        # pylint: disable=unused-variable
+        argtext = 'children=children, **args'
+    else:
+        default_argtext = ""
+        argtext = '**args'
+    default_argtext += ", ".join(
+        [('{:s}=Component.REQUIRED'.format(p)
+          if props[p]['required'] else
+          '{:s}=Component.UNDEFINED'.format(p))
+         for p in prop_keys
+         if not p.endswith("-*") and
+         p not in kwlist and
+         p not in ['dashEvents', 'fireEvent', 'setProps']] + ['**kwargs']
+    )
+
+    required_args = required_props(props)
+    return c.format(**locals())
+
+
+def generate_class_file(typename, props, description, namespace):
+    """
+    Generate a python class file (.py) given a class string
+
+    Parameters
+    ----------
+    typename
+    props
+    description
+    namespace
+
+    Returns
+    -------
+
+    """
+    import_string =\
+        "# AUTO GENERATED FILE - DO NOT EDIT\n\n" + \
+        "from dash.development.base_component import " + \
+        "Component, _explicitize_args\n\n\n"
+    class_string = generate_class_string(
+        typename,
+        props,
+        description,
+        namespace
+    )
+    file_name = "{:s}.py".format(typename)
+
+    file_path = os.path.join(namespace, file_name)
+    with open(file_path, 'w') as f:
+        f.write(import_string)
+        f.write(class_string)
+
+    print('Generated {}'.format(file_name))
+
+
+def generate_imports(project_shortname, components):
+    with open(os.path.join(project_shortname, '_imports_.py'), 'w') as f:
+        f.write(textwrap.dedent(
+            '''
+            {}
+
+            __all__ = [
+            {}
+            ]
+            '''.format(
+                '\n'.join(
+                    'from .{0} import {0}'.format(x) for x in components),
+                ',\n'.join('    "{}"'.format(x) for x in components)
+            )
+        ).lstrip())
+
+
+def generate_classes_files(project_shortname, metadata, *component_generators):
+    components = []
+    for component_path, component_data in metadata.items():
+        component_name = component_path.split('/')[-1].split('.')[0]
+        components.append(component_name)
+
+        for generator in component_generators:
+            generator(
+                component_name,
+                component_data['props'],
+                component_data['description'],
+                project_shortname
+            )
+
+    return components
+
+
+def generate_class(typename, props, description, namespace):
+    """
+    Generate a python class object given a class string
+
+    Parameters
+    ----------
+    typename
+    props
+    description
+    namespace
+
+    Returns
+    -------
+
+    """
+    string = generate_class_string(typename, props, description, namespace)
+    scope = {'Component': Component, '_explicitize_args': _explicitize_args}
+    # pylint: disable=exec-used
+    exec(string, scope)
+    result = scope[typename]
+    return result
+
+
+def required_props(props):
+    """
+    Pull names of required props from the props object
+
+    Parameters
+    ----------
+    props: dict
+
+    Returns
+    -------
+    list
+        List of prop names (str) that are required for the Component
+    """
+    return [prop_name for prop_name, prop in list(props.items())
+            if prop['required']]
+
+
+def create_docstring(component_name, props, events, description):
+    """
+    Create the Dash component docstring
+
+    Parameters
+    ----------
+    component_name: str
+        Component name
+    props: dict
+        Dictionary with {propName: propMetadata} structure
+    events: list
+        List of Dash events
+    description: str
+        Component description
+
+    Returns
+    -------
+    str
+        Dash component docstring
+    """
+    # Ensure props are ordered with children first
+    props = reorder_props(props=props)
+
+    return (
+        """A {name} component.\n{description}
+
+Keyword arguments:\n{args}
+
+Available events: {events}"""
+    ).format(
+        name=component_name,
+        description=description,
+        args='\n'.join(
+            create_prop_docstring(
+                prop_name=p,
+                type_object=prop['type'] if 'type' in prop
+                else prop['flowType'],
+                required=prop['required'],
+                description=prop['description'],
+                indent_num=0,
+                is_flow_type='flowType' in prop and 'type' not in prop)
+            for p, prop in list(filter_props(props).items())),
+        events=', '.join(events))
+
+
+def parse_events(props):
+    """
+    Pull out the dashEvents from the Component props
+
+    Parameters
+    ----------
+    props: dict
+        Dictionary with {propName: propMetadata} structure
+
+    Returns
+    -------
+    list
+        List of Dash event strings
+    """
+    if 'dashEvents' in props and props['dashEvents']['type']['name'] == 'enum':
+        events = [v['value'] for v in props['dashEvents']['type']['value']]
+    else:
+        events = []
+
+    return events
+
+
+def parse_wildcards(props):
+    """
+    Pull out the wildcard attributes from the Component props
+
+    Parameters
+    ----------
+    props: dict
+        Dictionary with {propName: propMetadata} structure
+
+    Returns
+    -------
+    list
+        List of Dash valid wildcard prefixes
+    """
+    list_of_valid_wildcard_attr_prefixes = []
+    for wildcard_attr in ["data-*", "aria-*"]:
+        if wildcard_attr in props.keys():
+            list_of_valid_wildcard_attr_prefixes.append(wildcard_attr[:-1])
+    return list_of_valid_wildcard_attr_prefixes
+
+
+def reorder_props(props):
+    """
+    If "children" is in props, then move it to the
+    front to respect dash convention
+
+    Parameters
+    ----------
+    props: dict
+        Dictionary with {propName: propMetadata} structure
+
+    Returns
+    -------
+    dict
+        Dictionary with {propName: propMetadata} structure
+    """
+    if 'children' in props:
+        props = collections.OrderedDict(
+            [('children', props.pop('children'),)] +
+            list(zip(list(props.keys()), list(props.values()))))
+
+    return props
+
+
+def filter_props(props):
+    """
+    Filter props from the Component arguments to exclude:
+        - Those without a "type" or a "flowType" field
+        - Those with arg.type.name in {'func', 'symbol', 'instanceOf'}
+        - dashEvents as a name
+
+    Parameters
+    ----------
+    props: dict
+        Dictionary with {propName: propMetadata} structure
+
+    Returns
+    -------
+    dict
+        Filtered dictionary with {propName: propMetadata} structure
+
+    Examples
+    --------
+    ```python
+    prop_args = {
+        'prop1': {
+            'type': {'name': 'bool'},
+            'required': False,
+            'description': 'A description',
+            'flowType': {},
+            'defaultValue': {'value': 'false', 'computed': False},
+        },
+        'prop2': {'description': 'A prop without a type'},
+        'prop3': {
+            'type': {'name': 'func'},
+            'description': 'A function prop',
+        },
+    }
+    # filtered_prop_args is now
+    # {
+    #    'prop1': {
+    #        'type': {'name': 'bool'},
+    #        'required': False,
+    #        'description': 'A description',
+    #        'flowType': {},
+    #        'defaultValue': {'value': 'false', 'computed': False},
+    #    },
+    # }
+    filtered_prop_args = filter_props(prop_args)
+    ```
+    """
+    filtered_props = copy.deepcopy(props)
+
+    for arg_name, arg in list(filtered_props.items()):
+        if 'type' not in arg and 'flowType' not in arg:
+            filtered_props.pop(arg_name)
+            continue
+
+        # Filter out functions and instances --
+        # these cannot be passed from Python
+        if 'type' in arg:  # These come from PropTypes
+            arg_type = arg['type']['name']
+            if arg_type in {'func', 'symbol', 'instanceOf'}:
+                filtered_props.pop(arg_name)
+        elif 'flowType' in arg:  # These come from Flow & handled differently
+            arg_type_name = arg['flowType']['name']
+            if arg_type_name == 'signature':
+                # This does the same as the PropTypes filter above, but "func"
+                # is under "type" if "name" is "signature" vs just in "name"
+                if 'type' not in arg['flowType'] \
+                        or arg['flowType']['type'] != 'object':
+                    filtered_props.pop(arg_name)
+        else:
+            raise ValueError
+
+        # dashEvents are a special oneOf property that is used for subscribing
+        # to events but it's never set as a property
+        if arg_name in ['dashEvents']:
+            filtered_props.pop(arg_name)
+    return filtered_props
+
+
+# pylint: disable=too-many-arguments
+def create_prop_docstring(prop_name, type_object, required, description,
+                          indent_num, is_flow_type=False):
+    """
+    Create the Dash component prop docstring
+
+    Parameters
+    ----------
+    prop_name: str
+        Name of the Dash component prop
+    type_object: dict
+        react-docgen-generated prop type dictionary
+    required: bool
+        Component is required?
+    description: str
+        Dash component description
+    indent_num: int
+        Number of indents to use for the context block
+        (creates 2 spaces for every indent)
+    is_flow_type: bool
+        Does the prop use Flow types? Otherwise, uses PropTypes
+
+    Returns
+    -------
+    str
+        Dash component prop docstring
+    """
+    py_type_name = js_to_py_type(
+        type_object=type_object,
+        is_flow_type=is_flow_type,
+        indent_num=indent_num + 1)
+
+    indent_spacing = '  ' * indent_num
+    if '\n' in py_type_name:
+        return '{indent_spacing}- {name} ({is_required}): {description}. ' \
+               '{name} has the following type: {type}'.format(
+                   indent_spacing=indent_spacing,
+                   name=prop_name,
+                   type=py_type_name,
+                   description=description,
+                   is_required='required' if required else 'optional')
+    return '{indent_spacing}- {name} ({type}' \
+           '{is_required}){description}'.format(
+               indent_spacing=indent_spacing,
+               name=prop_name,
+               type='{}; '.format(py_type_name) if py_type_name else '',
+               description=(
+                   ': {}'.format(description) if description != '' else ''
+               ),
+               is_required='required' if required else 'optional')
+
+
+def map_js_to_py_types_prop_types(type_object):
+    """Mapping from the PropTypes js type object to the Python type"""
+    return dict(
+        array=lambda: 'list',
+        bool=lambda: 'boolean',
+        number=lambda: 'number',
+        string=lambda: 'string',
+        object=lambda: 'dict',
+        any=lambda: 'boolean | number | string | dict | list',
+        element=lambda: 'dash component',
+        node=lambda: 'a list of or a singular dash '
+                     'component, string or number',
+
+        # React's PropTypes.oneOf
+        enum=lambda: 'a value equal to: {}'.format(
+            ', '.join(
+                '{}'.format(str(t['value']))
+                for t in type_object['value'])),
+
+        # React's PropTypes.oneOfType
+        union=lambda: '{}'.format(
+            ' | '.join(
+                '{}'.format(js_to_py_type(subType))
+                for subType in type_object['value']
+                if js_to_py_type(subType) != '')),
+
+        # React's PropTypes.arrayOf
+        arrayOf=lambda: 'list'.format(  # pylint: disable=too-many-format-args
+            ' of {}s'.format(
+                js_to_py_type(type_object['value']))
+            if js_to_py_type(type_object['value']) != ''
+            else ''),
+
+        # React's PropTypes.objectOf
+        objectOf=lambda: (
+            'dict with strings as keys and values of type {}'
+            ).format(
+                js_to_py_type(type_object['value'])),
+
+        # React's PropTypes.shape
+        shape=lambda: 'dict containing keys {}.\n{}'.format(
+            ', '.join(
+                "'{}'".format(t)
+                for t in list(type_object['value'].keys())),
+            'Those keys have the following types: \n{}'.format(
+                '\n'.join(create_prop_docstring(
+                    prop_name=prop_name,
+                    type_object=prop,
+                    required=prop['required'],
+                    description=prop.get('description', ''),
+                    indent_num=1)
+                          for prop_name, prop in
+                          list(type_object['value'].items())))),
+    )
+
+
+def map_js_to_py_types_flow_types(type_object):
+    """Mapping from the Flow js types to the Python type"""
+    return dict(
+        array=lambda: 'list',
+        boolean=lambda: 'boolean',
+        number=lambda: 'number',
+        string=lambda: 'string',
+        Object=lambda: 'dict',
+        any=lambda: 'bool | number | str | dict | list',
+        Element=lambda: 'dash component',
+        Node=lambda: 'a list of or a singular dash '
+                     'component, string or number',
+
+        # React's PropTypes.oneOfType
+        union=lambda: '{}'.format(
+            ' | '.join(
+                '{}'.format(js_to_py_type(subType))
+                for subType in type_object['elements']
+                if js_to_py_type(subType) != '')),
+
+        # Flow's Array type
+        Array=lambda: 'list{}'.format(
+            ' of {}s'.format(
+                js_to_py_type(type_object['elements'][0]))
+            if js_to_py_type(type_object['elements'][0]) != ''
+            else ''),
+
+        # React's PropTypes.shape
+        signature=lambda indent_num: 'dict containing keys {}.\n{}'.format(
+            ', '.join("'{}'".format(d['key'])
+                      for d in type_object['signature']['properties']),
+            '{}Those keys have the following types: \n{}'.format(
+                '  ' * indent_num,
+                '\n'.join(
+                    create_prop_docstring(
+                        prop_name=prop['key'],
+                        type_object=prop['value'],
+                        required=prop['value']['required'],
+                        description=prop['value'].get('description', ''),
+                        indent_num=indent_num,
+                        is_flow_type=True)
+                    for prop in type_object['signature']['properties']))),
+    )
+
+
+def js_to_py_type(type_object, is_flow_type=False, indent_num=0):
+    """
+    Convert JS types to Python types for the component definition
+
+    Parameters
+    ----------
+    type_object: dict
+        react-docgen-generated prop type dictionary
+    is_flow_type: bool
+        Does the prop use Flow types? Otherwise, uses PropTypes
+    indent_num: int
+        Number of indents to use for the docstring for the prop
+
+    Returns
+    -------
+    str
+        Python type string
+    """
+    js_type_name = type_object['name']
+    js_to_py_types = map_js_to_py_types_flow_types(type_object=type_object) \
+        if is_flow_type \
+        else map_js_to_py_types_prop_types(type_object=type_object)
+
+    if 'computed' in type_object and type_object['computed'] \
+            or type_object.get('type', '') == 'function':
+        return ''
+    elif js_type_name in js_to_py_types:
+        if js_type_name == 'signature':  # This is a Flow object w/ signature
+            return js_to_py_types[js_type_name](indent_num)
+        # All other types
+        return js_to_py_types[js_type_name]()
+    return ''
diff --git a/dash/development/base_component.py b/dash/development/base_component.py
index af589f45a7..ce6aec0741 100644
--- a/dash/development/base_component.py
+++ b/dash/development/base_component.py
@@ -1,15 +1,10 @@
 import collections
-import copy
-import os
-import inspect
 import abc
+import inspect
 import sys
-import textwrap
 
 import six
 
-from ._all_keywords import kwlist
-
 
 # pylint: disable=no-init,too-few-public-methods
 class ComponentRegistry:
@@ -68,37 +63,6 @@ def _check_if_has_indexable_children(item):
         raise KeyError
 
 
-def _explicitize_args(func):
-    # Python 2
-    if hasattr(func, 'func_code'):
-        varnames = func.func_code.co_varnames
-    # Python 3
-    else:
-        varnames = func.__code__.co_varnames
-
-    def wrapper(*args, **kwargs):
-        if '_explicit_args' in kwargs.keys():
-            raise Exception('Variable _explicit_args should not be set.')
-        kwargs['_explicit_args'] = \
-            list(
-                set(
-                    list(varnames[:len(args)]) + [k for k, _ in kwargs.items()]
-                )
-            )
-        if 'self' in kwargs['_explicit_args']:
-            kwargs['_explicit_args'].remove('self')
-        return func(*args, **kwargs)
-
-    # If Python 3, we can set the function signature to be correct
-    if hasattr(inspect, 'signature'):
-        # pylint: disable=no-member
-        new_sig = inspect.signature(wrapper).replace(
-            parameters=inspect.signature(func).parameters.values()
-        )
-        wrapper.__signature__ = new_sig
-    return wrapper
-
-
 @six.add_metaclass(ComponentMeta)
 class Component(collections.MutableMapping):
     class _UNDEFINED(object):
@@ -313,610 +277,32 @@ def __len__(self):
         return length
 
 
-# pylint: disable=unused-argument
-def generate_class_string(typename, props, description, namespace):
-    """
-    Dynamically generate class strings to have nicely formatted docstrings,
-    keyword arguments, and repr
-
-    Inspired by http://jameso.be/2013/08/06/namedtuple.html
-
-    Parameters
-    ----------
-    typename
-    props
-    description
-    namespace
-
-    Returns
-    -------
-    string
-
-    """
-    # TODO _prop_names, _type, _namespace, available_events,
-    # and available_properties
-    # can be modified by a Dash JS developer via setattr
-    # TODO - Tab out the repr for the repr of these components to make it
-    # look more like a hierarchical tree
-    # TODO - Include "description" "defaultValue" in the repr and docstring
-    #
-    # TODO - Handle "required"
-    #
-    # TODO - How to handle user-given `null` values? I want to include
-    # an expanded docstring like Dropdown(value=None, id=None)
-    # but by templating in those None values, I have no way of knowing
-    # whether a property is None because the user explicitly wanted
-    # it to be `null` or whether that was just the default value.
-    # The solution might be to deal with default values better although
-    # not all component authors will supply those.
-    c = '''class {typename}(Component):
-    """{docstring}"""
-    @_explicitize_args
-    def __init__(self, {default_argtext}):
-        self._prop_names = {list_of_valid_keys}
-        self._type = '{typename}'
-        self._namespace = '{namespace}'
-        self._valid_wildcard_attributes =\
-            {list_of_valid_wildcard_attr_prefixes}
-        self.available_events = {events}
-        self.available_properties = {list_of_valid_keys}
-        self.available_wildcard_properties =\
-            {list_of_valid_wildcard_attr_prefixes}
-
-        _explicit_args = kwargs.pop('_explicit_args')
-        _locals = locals()
-        _locals.update(kwargs)  # For wildcard attrs
-        args = {{k: _locals[k] for k in _explicit_args if k != 'children'}}
-
-        for k in {required_args}:
-            if k not in args:
-                raise TypeError(
-                    'Required argument `' + k + '` was not specified.')
-        super({typename}, self).__init__({argtext})
-
-    def __repr__(self):
-        if(any(getattr(self, c, None) is not None
-               for c in self._prop_names
-               if c is not self._prop_names[0])
-           or any(getattr(self, c, None) is not None
-                  for c in self.__dict__.keys()
-                  if any(c.startswith(wc_attr)
-                  for wc_attr in self._valid_wildcard_attributes))):
-            props_string = ', '.join([c+'='+repr(getattr(self, c, None))
-                                      for c in self._prop_names
-                                      if getattr(self, c, None) is not None])
-            wilds_string = ', '.join([c+'='+repr(getattr(self, c, None))
-                                      for c in self.__dict__.keys()
-                                      if any([c.startswith(wc_attr)
-                                      for wc_attr in
-                                      self._valid_wildcard_attributes])])
-            return ('{typename}(' + props_string +
-                   (', ' + wilds_string if wilds_string != '' else '') + ')')
-        else:
-            return (
-                '{typename}(' +
-                repr(getattr(self, self._prop_names[0], None)) + ')')
-'''
-
-    filtered_props = reorder_props(filter_props(props))
-    # pylint: disable=unused-variable
-    list_of_valid_wildcard_attr_prefixes = repr(parse_wildcards(props))
-    # pylint: disable=unused-variable
-    list_of_valid_keys = repr(list(map(str, filtered_props.keys())))
-    # pylint: disable=unused-variable
-    docstring = create_docstring(
-        component_name=typename,
-        props=filtered_props,
-        events=parse_events(props),
-        description=description).replace('\r\n', '\n')
-
-    # pylint: disable=unused-variable
-    events = '[' + ', '.join(parse_events(props)) + ']'
-    prop_keys = list(props.keys())
-    if 'children' in props:
-        prop_keys.remove('children')
-        default_argtext = "children=None, "
-        # pylint: disable=unused-variable
-        argtext = 'children=children, **args'
-    else:
-        default_argtext = ""
-        argtext = '**args'
-    default_argtext += ", ".join(
-        [('{:s}=Component.REQUIRED'.format(p)
-          if props[p]['required'] else
-          '{:s}=Component.UNDEFINED'.format(p))
-         for p in prop_keys
-         if not p.endswith("-*") and
-         p not in kwlist and
-         p not in ['dashEvents', 'fireEvent', 'setProps']] + ['**kwargs']
-    )
-
-    required_args = required_props(props)
-    return c.format(**locals())
-
-
-# pylint: disable=unused-argument
-def generate_class_file(typename, props, description, namespace):
-    """
-    Generate a python class file (.py) given a class string
-
-    Parameters
-    ----------
-    typename
-    props
-    description
-    namespace
-
-    Returns
-    -------
-
-    """
-    import_string =\
-        "# AUTO GENERATED FILE - DO NOT EDIT\n\n" + \
-        "from dash.development.base_component import " + \
-        "Component, _explicitize_args\n\n\n"
-    class_string = generate_class_string(
-        typename,
-        props,
-        description,
-        namespace
-    )
-    file_name = "{:s}.py".format(typename)
-
-    file_path = os.path.join(namespace, file_name)
-    with open(file_path, 'w') as f:
-        f.write(import_string)
-        f.write(class_string)
-
-    print('Generated {}'.format(file_name))
-
-
-# pylint: disable=unused-argument
-def generate_class(typename, props, description, namespace):
-    """
-    Generate a python class object given a class string
-
-    Parameters
-    ----------
-    typename
-    props
-    description
-    namespace
-
-    Returns
-    -------
-
-    """
-    string = generate_class_string(typename, props, description, namespace)
-    scope = {'Component': Component, '_explicitize_args': _explicitize_args}
-    # pylint: disable=exec-used
-    exec(string, scope)
-    result = scope[typename]
-    return result
-
-
-def required_props(props):
-    """
-    Pull names of required props from the props object
-
-    Parameters
-    ----------
-    props: dict
-
-    Returns
-    -------
-    list
-        List of prop names (str) that are required for the Component
-    """
-    return [prop_name for prop_name, prop in list(props.items())
-            if prop['required']]
-
-
-def create_docstring(component_name, props, events, description):
-    """
-    Create the Dash component docstring
-
-    Parameters
-    ----------
-    component_name: str
-        Component name
-    props: dict
-        Dictionary with {propName: propMetadata} structure
-    events: list
-        List of Dash events
-    description: str
-        Component description
-
-    Returns
-    -------
-    str
-        Dash component docstring
-    """
-    # Ensure props are ordered with children first
-    props = reorder_props(props=props)
-
-    return (
-        """A {name} component.\n{description}
-
-Keyword arguments:\n{args}
-
-Available events: {events}"""
-    ).format(
-        name=component_name,
-        description=description,
-        args='\n'.join(
-            create_prop_docstring(
-                prop_name=p,
-                type_object=prop['type'] if 'type' in prop
-                else prop['flowType'],
-                required=prop['required'],
-                description=prop['description'],
-                indent_num=0,
-                is_flow_type='flowType' in prop and 'type' not in prop)
-            for p, prop in list(filter_props(props).items())),
-        events=', '.join(events))
-
-
-def parse_events(props):
-    """
-    Pull out the dashEvents from the Component props
-
-    Parameters
-    ----------
-    props: dict
-        Dictionary with {propName: propMetadata} structure
-
-    Returns
-    -------
-    list
-        List of Dash event strings
-    """
-    if 'dashEvents' in props and props['dashEvents']['type']['name'] == 'enum':
-        events = [v['value'] for v in props['dashEvents']['type']['value']]
+def _explicitize_args(func):
+    # Python 2
+    if hasattr(func, 'func_code'):
+        varnames = func.func_code.co_varnames
+    # Python 3
     else:
-        events = []
-
-    return events
-
-
-def parse_wildcards(props):
-    """
-    Pull out the wildcard attributes from the Component props
-
-    Parameters
-    ----------
-    props: dict
-        Dictionary with {propName: propMetadata} structure
-
-    Returns
-    -------
-    list
-        List of Dash valid wildcard prefixes
-    """
-    list_of_valid_wildcard_attr_prefixes = []
-    for wildcard_attr in ["data-*", "aria-*"]:
-        if wildcard_attr in props.keys():
-            list_of_valid_wildcard_attr_prefixes.append(wildcard_attr[:-1])
-    return list_of_valid_wildcard_attr_prefixes
-
-
-def reorder_props(props):
-    """
-    If "children" is in props, then move it to the
-    front to respect dash convention
-
-    Parameters
-    ----------
-    props: dict
-        Dictionary with {propName: propMetadata} structure
-
-    Returns
-    -------
-    dict
-        Dictionary with {propName: propMetadata} structure
-    """
-    if 'children' in props:
-        props = collections.OrderedDict(
-            [('children', props.pop('children'),)] +
-            list(zip(list(props.keys()), list(props.values()))))
-
-    return props
-
-
-def filter_props(props):
-    """
-    Filter props from the Component arguments to exclude:
-        - Those without a "type" or a "flowType" field
-        - Those with arg.type.name in {'func', 'symbol', 'instanceOf'}
-        - dashEvents as a name
-
-    Parameters
-    ----------
-    props: dict
-        Dictionary with {propName: propMetadata} structure
-
-    Returns
-    -------
-    dict
-        Filtered dictionary with {propName: propMetadata} structure
-
-    Examples
-    --------
-    ```python
-    prop_args = {
-        'prop1': {
-            'type': {'name': 'bool'},
-            'required': False,
-            'description': 'A description',
-            'flowType': {},
-            'defaultValue': {'value': 'false', 'computed': False},
-        },
-        'prop2': {'description': 'A prop without a type'},
-        'prop3': {
-            'type': {'name': 'func'},
-            'description': 'A function prop',
-        },
-    }
-    # filtered_prop_args is now
-    # {
-    #    'prop1': {
-    #        'type': {'name': 'bool'},
-    #        'required': False,
-    #        'description': 'A description',
-    #        'flowType': {},
-    #        'defaultValue': {'value': 'false', 'computed': False},
-    #    },
-    # }
-    filtered_prop_args = filter_props(prop_args)
-    ```
-    """
-    filtered_props = copy.deepcopy(props)
-
-    for arg_name, arg in list(filtered_props.items()):
-        if 'type' not in arg and 'flowType' not in arg:
-            filtered_props.pop(arg_name)
-            continue
-
-        # Filter out functions and instances --
-        # these cannot be passed from Python
-        if 'type' in arg:  # These come from PropTypes
-            arg_type = arg['type']['name']
-            if arg_type in {'func', 'symbol', 'instanceOf'}:
-                filtered_props.pop(arg_name)
-        elif 'flowType' in arg:  # These come from Flow & handled differently
-            arg_type_name = arg['flowType']['name']
-            if arg_type_name == 'signature':
-                # This does the same as the PropTypes filter above, but "func"
-                # is under "type" if "name" is "signature" vs just in "name"
-                if 'type' not in arg['flowType'] \
-                        or arg['flowType']['type'] != 'object':
-                    filtered_props.pop(arg_name)
-        else:
-            raise ValueError
-
-        # dashEvents are a special oneOf property that is used for subscribing
-        # to events but it's never set as a property
-        if arg_name in ['dashEvents']:
-            filtered_props.pop(arg_name)
-    return filtered_props
-
-
-# pylint: disable=too-many-arguments
-def create_prop_docstring(prop_name, type_object, required, description,
-                          indent_num, is_flow_type=False):
-    """
-    Create the Dash component prop docstring
-
-    Parameters
-    ----------
-    prop_name: str
-        Name of the Dash component prop
-    type_object: dict
-        react-docgen-generated prop type dictionary
-    required: bool
-        Component is required?
-    description: str
-        Dash component description
-    indent_num: int
-        Number of indents to use for the context block
-        (creates 2 spaces for every indent)
-    is_flow_type: bool
-        Does the prop use Flow types? Otherwise, uses PropTypes
-
-    Returns
-    -------
-    str
-        Dash component prop docstring
-    """
-    py_type_name = js_to_py_type(
-        type_object=type_object,
-        is_flow_type=is_flow_type,
-        indent_num=indent_num + 1)
-
-    indent_spacing = '  ' * indent_num
-    if '\n' in py_type_name:
-        return '{indent_spacing}- {name} ({is_required}): {description}. ' \
-               '{name} has the following type: {type}'.format(
-                   indent_spacing=indent_spacing,
-                   name=prop_name,
-                   type=py_type_name,
-                   description=description,
-                   is_required='required' if required else 'optional')
-    return '{indent_spacing}- {name} ({type}' \
-           '{is_required}){description}'.format(
-               indent_spacing=indent_spacing,
-               name=prop_name,
-               type='{}; '.format(py_type_name) if py_type_name else '',
-               description=(
-                   ': {}'.format(description) if description != '' else ''
-               ),
-               is_required='required' if required else 'optional')
-
-
-def map_js_to_py_types_prop_types(type_object):
-    """Mapping from the PropTypes js type object to the Python type"""
-    return dict(
-        array=lambda: 'list',
-        bool=lambda: 'boolean',
-        number=lambda: 'number',
-        string=lambda: 'string',
-        object=lambda: 'dict',
-        any=lambda: 'boolean | number | string | dict | list',
-        element=lambda: 'dash component',
-        node=lambda: 'a list of or a singular dash '
-                     'component, string or number',
-
-        # React's PropTypes.oneOf
-        enum=lambda: 'a value equal to: {}'.format(
-            ', '.join(
-                '{}'.format(str(t['value']))
-                for t in type_object['value'])),
-
-        # React's PropTypes.oneOfType
-        union=lambda: '{}'.format(
-            ' | '.join(
-                '{}'.format(js_to_py_type(subType))
-                for subType in type_object['value']
-                if js_to_py_type(subType) != '')),
-
-        # React's PropTypes.arrayOf
-        arrayOf=lambda: 'list'.format(  # pylint: disable=too-many-format-args
-            ' of {}s'.format(
-                js_to_py_type(type_object['value']))
-            if js_to_py_type(type_object['value']) != ''
-            else ''),
-
-        # React's PropTypes.objectOf
-        objectOf=lambda: (
-            'dict with strings as keys and values of type {}'
-            ).format(
-                js_to_py_type(type_object['value'])),
-
-        # React's PropTypes.shape
-        shape=lambda: 'dict containing keys {}.\n{}'.format(
-            ', '.join(
-                "'{}'".format(t)
-                for t in list(type_object['value'].keys())),
-            'Those keys have the following types: \n{}'.format(
-                '\n'.join(create_prop_docstring(
-                    prop_name=prop_name,
-                    type_object=prop,
-                    required=prop['required'],
-                    description=prop.get('description', ''),
-                    indent_num=1)
-                          for prop_name, prop in
-                          list(type_object['value'].items())))),
-    )
-
-
-def map_js_to_py_types_flow_types(type_object):
-    """Mapping from the Flow js types to the Python type"""
-    return dict(
-        array=lambda: 'list',
-        boolean=lambda: 'boolean',
-        number=lambda: 'number',
-        string=lambda: 'string',
-        Object=lambda: 'dict',
-        any=lambda: 'bool | number | str | dict | list',
-        Element=lambda: 'dash component',
-        Node=lambda: 'a list of or a singular dash '
-                     'component, string or number',
-
-        # React's PropTypes.oneOfType
-        union=lambda: '{}'.format(
-            ' | '.join(
-                '{}'.format(js_to_py_type(subType))
-                for subType in type_object['elements']
-                if js_to_py_type(subType) != '')),
-
-        # Flow's Array type
-        Array=lambda: 'list{}'.format(
-            ' of {}s'.format(
-                js_to_py_type(type_object['elements'][0]))
-            if js_to_py_type(type_object['elements'][0]) != ''
-            else ''),
-
-        # React's PropTypes.shape
-        signature=lambda indent_num: 'dict containing keys {}.\n{}'.format(
-            ', '.join("'{}'".format(d['key'])
-                      for d in type_object['signature']['properties']),
-            '{}Those keys have the following types: \n{}'.format(
-                '  ' * indent_num,
-                '\n'.join(
-                    create_prop_docstring(
-                        prop_name=prop['key'],
-                        type_object=prop['value'],
-                        required=prop['value']['required'],
-                        description=prop['value'].get('description', ''),
-                        indent_num=indent_num,
-                        is_flow_type=True)
-                    for prop in type_object['signature']['properties']))),
-    )
-
-
-def js_to_py_type(type_object, is_flow_type=False, indent_num=0):
-    """
-    Convert JS types to Python types for the component definition
-
-    Parameters
-    ----------
-    type_object: dict
-        react-docgen-generated prop type dictionary
-    is_flow_type: bool
-        Does the prop use Flow types? Otherwise, uses PropTypes
-    indent_num: int
-        Number of indents to use for the docstring for the prop
-
-    Returns
-    -------
-    str
-        Python type string
-    """
-    js_type_name = type_object['name']
-    js_to_py_types = map_js_to_py_types_flow_types(type_object=type_object) \
-        if is_flow_type \
-        else map_js_to_py_types_prop_types(type_object=type_object)
-
-    if 'computed' in type_object and type_object['computed'] \
-            or type_object.get('type', '') == 'function':
-        return ''
-    elif js_type_name in js_to_py_types:
-        if js_type_name == 'signature':  # This is a Flow object w/ signature
-            return js_to_py_types[js_type_name](indent_num)
-        # All other types
-        return js_to_py_types[js_type_name]()
-    return ''
-
-
-def generate_imports(project_shortname, components):
-    with open(os.path.join(project_shortname, '_imports_.py'), 'w') as f:
-        f.write(textwrap.dedent(
-            '''
-            {}
-
-            __all__ = [
-            {}
-            ]
-            '''.format(
-                '\n'.join(
-                    'from .{0} import {0}'.format(x) for x in components),
-                ',\n'.join('    "{}"'.format(x) for x in components)
-            )
-        ).lstrip())
-
-
-def generate_classes_files(project_shortname, metadata, *component_generators):
-    components = []
-    for component_path, component_data in metadata.items():
-        component_name = component_path.split('/')[-1].split('.')[0]
-        components.append(component_name)
+        varnames = func.__code__.co_varnames
 
-        for generator in component_generators:
-            generator(
-                component_name,
-                component_data['props'],
-                component_data['description'],
-                project_shortname
+    def wrapper(*args, **kwargs):
+        if '_explicit_args' in kwargs.keys():
+            raise Exception('Variable _explicit_args should not be set.')
+        kwargs['_explicit_args'] = \
+            list(
+                set(
+                    list(varnames[:len(args)]) + [k for k, _ in kwargs.items()]
+                )
             )
+        if 'self' in kwargs['_explicit_args']:
+            kwargs['_explicit_args'].remove('self')
+        return func(*args, **kwargs)
 
-    return components
+    # If Python 3, we can set the function signature to be correct
+    if hasattr(inspect, 'signature'):
+        # pylint: disable=no-member
+        new_sig = inspect.signature(wrapper).replace(
+            parameters=inspect.signature(func).parameters.values()
+        )
+        wrapper.__signature__ = new_sig
+    return wrapper
diff --git a/dash/development/component_generator.py b/dash/development/component_generator.py
index 6c2f9bd842..8e04e0eab4 100644
--- a/dash/development/component_generator.py
+++ b/dash/development/component_generator.py
@@ -7,12 +7,12 @@
 import os
 import argparse
 import shutil
-import pkg_resources
 
+import pkg_resources
 
-from .base_component import generate_class_file
-from .base_component import generate_imports
-from .base_component import generate_classes_files
+from ._py_components_generation import generate_class_file
+from ._py_components_generation import generate_imports
+from ._py_components_generation import generate_classes_files
 
 
 class _CombinedFormatter(argparse.ArgumentDefaultsHelpFormatter,
diff --git a/dash/development/component_loader.py b/dash/development/component_loader.py
index 99a451fd29..968a3fa1d1 100644
--- a/dash/development/component_loader.py
+++ b/dash/development/component_loader.py
@@ -2,10 +2,12 @@
 import json
 import os
 
-from .base_component import generate_imports
-from .base_component import generate_classes_files
-from .base_component import generate_class
-from .base_component import generate_class_file
+from ._py_components_generation import (
+    generate_class_file,
+    generate_imports,
+    generate_classes_files,
+    generate_class
+)
 from .base_component import ComponentRegistry
 
 
diff --git a/tests/development/test_base_component.py b/tests/development/test_base_component.py
index a43be1b898..9e725f5903 100644
--- a/tests/development/test_base_component.py
+++ b/tests/development/test_base_component.py
@@ -8,15 +8,10 @@
 import plotly
 
 from dash.development.base_component import (
-    generate_class,
-    generate_class_string,
-    generate_class_file,
     Component,
-    _explicitize_args,
-    js_to_py_type,
-    create_docstring,
-    parse_events
-)
+    _explicitize_args)
+from dash.development._py_components_generation import generate_class_string, generate_class_file, generate_class, \
+    create_docstring, parse_events, js_to_py_type
 
 Component._prop_names = ('id', 'a', 'children', 'style', )
 Component._type = 'TestComponent'
diff --git a/tests/development/test_component_loader.py b/tests/development/test_component_loader.py
index a4fb4423e1..7f3ce871fb 100644
--- a/tests/development/test_component_loader.py
+++ b/tests/development/test_component_loader.py
@@ -5,9 +5,9 @@
 import unittest
 from dash.development.component_loader import load_components, generate_classes
 from dash.development.base_component import (
-    generate_class,
     Component
 )
+from dash.development._py_components_generation import generate_class
 
 METADATA_PATH = 'metadata.json'
 
diff --git a/tests/test_resources.py b/tests/test_resources.py
index a25553abe5..f0214f45b2 100644
--- a/tests/test_resources.py
+++ b/tests/test_resources.py
@@ -1,7 +1,7 @@
 import unittest
 import warnings
 from dash.resources import Scripts, Css
-from dash.development.base_component import generate_class
+from dash.development._py_components_generation import generate_class
 
 
 def generate_components():

From a4924483ab937b3b8f7bbd68f5b1aa56b037b1c5 Mon Sep 17 00:00:00 2001
From: Philippe Duval <philippe@plot.ly>
Date: Mon, 26 Nov 2018 17:25:01 -0500
Subject: [PATCH 25/25] Update version and changelog.

---
 CHANGELOG.md    | 4 ++++
 dash/version.py | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1e82d00ea4..fcf11203b8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.31.0 - 2018-11-26
+## Added
+- Combined `extract-meta` and python component files generation in a cli [#451](https://github.com/plotly/dash/pull/451)
+
 ## 0.30.0 - 2018-11-14
 ## Added
 - Hot reload from the browser [#362](https://github.com/plotly/dash/pull/362)
diff --git a/dash/version.py b/dash/version.py
index e187e0aa61..c3d10d7c49 100644
--- a/dash/version.py
+++ b/dash/version.py
@@ -1 +1 @@
-__version__ = '0.30.0'
+__version__ = '0.31.0'