execute.go

/**
 * @license
 * Copyright Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package main

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"os"

	"golang.org/x/net/context"
	"golang.org/x/oauth2"
	"golang.org/x/oauth2/google"
	script "google.golang.org/api/script/v1"
)

// Retrieve a token, saves the token, then returns the generated client.
func getClient(config *oauth2.Config) *http.Client {
	// The file token.json stores the user's access and refresh tokens, and is
	// created automatically when the authorization flow completes for the first
	// time.
	tokFile := "token.json"
	tok, err := tokenFromFile(tokFile)
	if err != nil {
		tok = getTokenFromWeb(config)
		saveToken(tokFile, tok)
	}
	return config.Client(context.Background(), tok)
}

// Request a token from the web, then returns the retrieved token.
func getTokenFromWeb(config *oauth2.Config) *oauth2.Token {
	authURL := config.AuthCodeURL("state-token", oauth2.AccessTypeOffline)
	fmt.Printf("Go to the following link in your browser then type the "+
		"authorization code: \n%v\n", authURL)

	var authCode string
	if _, err := fmt.Scan(&authCode); err != nil {
		log.Fatalf("Unable to read authorization code: %v", err)
	}

	tok, err := config.Exchange(context.TODO(), authCode)
	if err != nil {
		log.Fatalf("Unable to retrieve token from web: %v", err)
	}
	return tok
}

// Retrieves a token from a local file.
func tokenFromFile(file string) (*oauth2.Token, error) {
	f, err := os.Open(file)
	if err != nil {
		return nil, err
	}
	defer f.Close()
	tok := &oauth2.Token{}
	err = json.NewDecoder(f).Decode(tok)
	return tok, err
}

// Saves a token to a file path.
func saveToken(path string, token *oauth2.Token) {
	fmt.Printf("Saving credential file to: %s\n", path)
	f, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
	if err != nil {
		log.Fatalf("Unable to cache oauth token: %v", err)
	}
	defer f.Close()
	json.NewEncoder(f).Encode(token)
}

func main() {
	// [START apps_script_api_execute]

	scriptId := "ENTER_YOUR_SCRIPT_ID_HERE"

	b, err := ioutil.ReadFile("credentials.json")
	if err != nil {
		log.Fatalf("Unable to read client secret file: %v", err)
	}

	// If modifying these scopes, delete your previously saved token.json.
	config, err := google.ConfigFromJSON(b, "https://www.googleapis.com/auth/script.projects")
	if err != nil {
		log.Fatalf("Unable to parse client secret file to config: %v", err)
	}

	client := getClient(config)

	// Generate a service object.
	srv, err := script.New(client)
	if err != nil {
		log.Fatalf("Unable to retrieve script Client %v", err)
	}

	// Create an execution request object.
	req := script.ExecutionRequest{Function: "getFoldersUnderRoot"}

	// Make the API request.
	resp, err := srv.Scripts.Run(scriptId, &req).Do()
	if err != nil {
		// The API encountered a problem before the script started executing.
		log.Fatalf("Unable to execute Apps Script function. %v", err)
	}

	if resp.Error != nil {
		// The API executed, but the script returned an details.

		// Extract the first (and only) set of details details and cast as a map.
		// The values of this map are the script's 'errorMessage' and
		// 'errorType', and an array of stack trace elements (which also need to
		// be cast as maps).
		var details map[string]interface{}
		json.Unmarshal(resp.Error.Details[0], &details)
		fmt.Printf("Script details message: %s\n", details["errorMessage"])

		if details["scriptStackTraceElements"] != nil {
			// There may not be a stacktrace if the script didn't start executing.
			fmt.Printf("Script details stacktrace:\n")
			for _, trace := range details["scriptStackTraceElements"].([]interface{}) {
				t := trace.(map[string]interface{})
				fmt.Printf("\t%s: %d\n", t["function"], int(t["lineNumber"].(float64)))
			}
		}
	} else {
		// The result provided by the API needs to be cast into the correct type,
		// based upon what types the Apps Script function returns. Here, the
		// function returns an Apps Script Object with String keys and values, so
		// must be cast into a map (folderSet).
		var r map[string]interface{}
		json.Unmarshal(resp.Response, &r)
		folderSet := r["result"].(map[string]interface{})
		if len(folderSet) == 0 {
			fmt.Printf("No folders returned!\n")
		} else {
			fmt.Printf("Folders under your root folder:\n")
			for id, folder := range folderSet {
				fmt.Printf("\t%s (%s)\n", folder, id)
			}
		}
	}
	// [END apps_script_api_execute]
}