add runnable example

.github/workflows/dart.yml

@@ -19,3 +19,8 @@ jobs:
       env:
         UNSPLASH_ACCESS_KEY: ${{ secrets.UNSPLASH_ACCESS_KEY }}
         UNSPLASH_SECRET_KEY: ${{ secrets.UNSPLASH_SECRET_KEY }}
+    - name: Run example
+      run: dart example/lib/main.dart
+      env:
+        UNSPLASH_ACCESS_KEY: ${{ secrets.UNSPLASH_ACCESS_KEY }}
+        UNSPLASH_SECRET_KEY: ${{ secrets.UNSPLASH_SECRET_KEY }}

README.md

@@ -45,41 +45,4 @@ This is a work in progress:
 
 ## Usage
 
-A simple usage example:
-
-```dart
-import 'package:unsplash_client/unsplash_client.dart';
-
-void main() async {
-  // Create a client.
-  final client = UnsplashClient(
-    settings: Settings(
-      // Use the credentials from the developer portal.
-      credentials: AppCredentials(
-        accessKey: '...',
-        secretKey: '...',
-      )     
-    ),
-  );
-  
-  // Fetch 5 random photos.
-  final response = await client.photos.random(count: 5).go();
-  
-  // Check that the request was successful.
-  if (!response.isOk) {
-    throw 'Something is wrong: $response';
-  }
-  
-  // Do something with the photos.
-  final photos = response.data;
-  
-  // Create a dynamically resizing url.
-  final resizedUrl = photos.first.urls.raw.resize(
-    width: 400,
-    height: 400,
-    fit: ResizeFitMode.cover,
-    format: ImageFormat.webp,
-  );
-
-}
-```
+See examples tab.

example/lib/main.dart

@@ -0,0 +1,72 @@
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:unsplash_client/unsplash_client.dart';
+
+void main(List<String> args) async {
+  // Load app credentials from environment variables or file.
+  var appCredentials = loadAppCredentialsFromEnv();
+
+  if (appCredentials == null) {
+    if (args.length != 1) {
+      throw "Please provide a credentials file as the first and only argument.";
+    }
+
+    appCredentials = await loadAppCredentialsFromFile(args.first);
+  }
+
+  // Create a client.
+  final client = UnsplashClient(
+    settings: ClientSettings(credentials: appCredentials),
+  );
+
+  // Fetch 5 random photos.
+  final response = await client.photos.random(count: 2).go();
+
+  // Check that the request was successful.
+  if (!response.isOk) {
+    throw 'Something is wrong: $response';
+  }
+
+  // Do something with the photos.
+  final photos = response.data;
+  print("--- Photos");
+  print(photos);
+  print("---\n");
+
+  // Create a dynamically resizing url.
+  final resizedUrl = photos.first.urls.raw.resizePhoto(
+    width: 400,
+    height: 400,
+    fit: ResizeFitMode.clamp,
+    format: ImageFormat.webp,
+  );
+  print("--- Resized Url");
+  print(resizedUrl);
+}
+
+/// Loads [AppCredentials] from environment variables
+/// (`UNSPLASH_ACCESS_KEY`, `UNSPLASH_SECRET_KEY`).
+///
+/// Returns `null` if the variables do not exist.
+AppCredentials loadAppCredentialsFromEnv() {
+  final accessKey = Platform.environment['UNSPLASH_ACCESS_KEY'];
+  final secretKey = Platform.environment['UNSPLASH_SECRET_KEY'];
+
+  if (accessKey != null && secretKey != null) {
+    return AppCredentials(
+      accessKey: accessKey,
+      secretKey: secretKey,
+    );
+  }
+
+  return null;
+}
+
+/// Loads [AppCredentials] from a json file with the given [fileName].
+Future<AppCredentials> loadAppCredentialsFromFile(String fileName) async {
+  final file = File(fileName);
+  final content = await file.readAsString();
+  final json = jsonDecode(content) as Map<String, dynamic>;
+  return AppCredentials.fromJson(json);
+}

example/pubspec.yaml

@@ -0,0 +1,5 @@
+name: example
+
+dependencies:
+  unsplash_client:
+    path: ../