बदलाव फिर से पाएं

Google Drive के उन ऐप्लिकेशन के लिए, changes कलेक्शन, फ़ाइलों में हुए सभी बदलावों का पता लगाने का एक बेहतर तरीका उपलब्ध कराता है. इनमें, किसी उपयोगकर्ता के साथ शेयर की गई फ़ाइलों में हुए बदलाव भी शामिल हैं. अगर फ़ाइल में बदलाव हुआ है, तो कलेक्शन में हर फ़ाइल की मौजूदा स्थिति दिखती है.

स्टार्ट पेज का टोकन पाना

खाते की मौजूदा स्थिति के लिए पेज टोकन का अनुरोध करने के लिए, changes.getStartPageToken का इस्तेमाल करें. changes.list को कॉल करने के लिए, इस टोकन को सेव करें और इसका इस्तेमाल करें.

मौजूदा पेज का टोकन पाने के लिए:

Java

drive/snippets/drive_v3/src/main/java/FetchStartPageToken.java

GitHub पर देखना

import com.google.api.client.googleapis.json.GoogleJsonResponseException;
import com.google.api.client.http.HttpRequestInitializer;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.services.drive.Drive;
import com.google.api.services.drive.DriveScopes;
import com.google.api.services.drive.model.StartPageToken;
import com.google.auth.http.HttpCredentialsAdapter;
import com.google.auth.oauth2.GoogleCredentials;
import java.io.IOException;
import java.util.Arrays;

/* Class to demonstrate use-case of Drive's fetch start page token */
public class FetchStartPageToken {

  /**
   * Retrieve the start page token for the first time.
   *
   * @return Start page token as String.
   * @throws IOException if file is not found
   */
  public static String fetchStartPageToken() throws IOException {
        /*Load pre-authorized user credentials from the environment.
        TODO(developer) - See https://developers.google.com/identity for
        guides on implementing OAuth2 for your application. */

    GoogleCredentials credentials = GoogleCredentials.getApplicationDefault()
        .createScoped(Arrays.asList(DriveScopes.DRIVE_FILE));
    HttpRequestInitializer requestInitializer = new HttpCredentialsAdapter(
        credentials);

    // Build a new authorized API client service.
    Drive service = new Drive.Builder(new NetHttpTransport(),
        GsonFactory.getDefaultInstance(),
        requestInitializer)
        .setApplicationName("Drive samples")
        .build();
    try {
      StartPageToken response = service.changes()
          .getStartPageToken().execute();
      System.out.println("Start token: " + response.getStartPageToken());

      return response.getStartPageToken();
    } catch (GoogleJsonResponseException e) {
      // TODO(developer) - handle error appropriately
      System.err.println("Unable to fetch start page token: " + e.getDetails());
      throw e;
    }
  }

}

Python

drive/snippets/drive-v3/change_snippet/fetch_start_page_token.py

GitHub पर देखना

import google.auth
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError


def fetch_start_page_token():
  """Retrieve page token for the current state of the account.
  Returns & prints : start page token

  Load pre-authorized user credentials from the environment.
  TODO(developer) - See https://developers.google.com/identity
  for guides on implementing OAuth2 for the application.
  """
  creds, _ = google.auth.default()

  try:
    # create drive api client
    service = build("drive", "v3", credentials=creds)

    # pylint: disable=maybe-no-member
    response = service.changes().getStartPageToken().execute()
    print(f'Start token: {response.get("startPageToken")}')

  except HttpError as error:
    print(f"An error occurred: {error}")
    response = None

  return response.get("startPageToken")


if __name__ == "__main__":
  fetch_start_page_token()

PHP

drive/snippets/drive_v3/src/DriveFetchStartPageToken.php

GitHub पर देखना

use Google\Client;
use Google\Service\Drive;
# TODO - PHP client currently chokes on fetching start page token
function fetchStartPageToken()
{
    try {
        $client = new Client();
        $client->useApplicationDefaultCredentials();
        $client->addScope(Drive::DRIVE);
        $driveService = new Drive($client);
        $response = $driveService->changes->getStartPageToken();
        printf("Start token: %s\n", $response->startPageToken);
        return $response->startPageToken;
    } catch(Exception $e) {
        echo "Error Message: ".$e;
    }

}

.NET

drive/snippets/drive_v3/DriveV3Snippets/FetchStartPageToken.cs

GitHub पर देखना

using Google.Apis.Auth.OAuth2;
using Google.Apis.Drive.v3;
using Google.Apis.Services;

namespace DriveV3Snippets
{
    // Class to demonstrate use-case of Drive's fetch start page token
    public class FetchStartPageToken
    {
        /// <summary>
        /// Retrieve the starting page token.
        /// </summary>
        /// <returns>start page token as String, null otherwise.</returns>
        public static string DriveFetchStartPageToken()
        {
            try
            {
                /* Load pre-authorized user credentials from the environment.
                 TODO(developer) - See https://developers.google.com/identity for
                 guides on implementing OAuth2 for your application. */
                GoogleCredential credential = GoogleCredential.GetApplicationDefault()
                    .CreateScoped(DriveService.Scope.Drive);

                // Create Drive API service.
                var service = new DriveService(new BaseClientService.Initializer
                {
                    HttpClientInitializer = credential,
                    ApplicationName = "Drive API Snippets"
                });

                var response = service.Changes.GetStartPageToken().Execute();
                // Prints the token value.
                Console.WriteLine("Start token: " + response.StartPageTokenValue);
                return response.StartPageTokenValue;
            }
            catch (Exception e)
            {
                // TODO(developer) - handle error appropriately
                if (e is AggregateException)
                {
                    Console.WriteLine("Credential Not found");
                }
                else
                {
                    throw;
                }
            }
            return null;
        }
    }
}

Node.js

drive/snippets/drive_v3/change_snippets/fetch_start_page_token.js

GitHub पर देखना

/**
 * Retrieve page token for the current state of the account.
 **/
async function fetchStartPageToken() {
  // Get credentials and build service
  // TODO (developer) - Use appropriate auth mechanism for your app

  const {GoogleAuth} = require('google-auth-library');
  const {google} = require('googleapis');

  const auth = new GoogleAuth({
    scopes: 'https://www.googleapis.com/auth/drive.appdata',
  });
  const service = google.drive({version: 'v3', auth});
  try {
    const res = await service.changes.getStartPageToken({});
    const token = res.data.startPageToken;
    console.log('start token: ', token);
    return token;
  } catch (err) {
    // TODO(developer) - Handle error
    throw err;
  }
}

बदलाव पाना

फ़िलहाल साइन इन किए हुए उपयोगकर्ता के लिए, बदलावों की सूची पाने के लिए, GET changes कलेक्शन के लिए अनुरोध भेजें. इस बारे में ज़्यादा जानकारी, changes.list में दी गई है.

changes कलेक्शन में मौजूद एंट्री, समय के हिसाब से क्रम में होती हैं. सबसे पुराने बदलाव सबसे पहले दिखते हैं. includeRemoved और restrictToMyDrive क्वेरी पैरामीटर से यह तय होता है कि जवाब में हटाए गए या शेयर किए गए आइटम शामिल होने चाहिए या नहीं.

Java

drive/snippets/drive_v3/src/main/java/FetchChanges.java

GitHub पर देखना

import com.google.api.client.googleapis.json.GoogleJsonResponseException;
import com.google.api.client.http.HttpRequestInitializer;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.services.drive.Drive;
import com.google.api.services.drive.DriveScopes;
import com.google.api.services.drive.model.ChangeList;
import com.google.auth.http.HttpCredentialsAdapter;
import com.google.auth.oauth2.GoogleCredentials;
import java.io.IOException;
import java.util.Arrays;

/* Class to demonstrate use-case of Drive's fetch changes in file. */
public class FetchChanges {
  /**
   * Retrieve the list of changes for the currently authenticated user.
   *
   * @param savedStartPageToken Last saved start token for this user.
   * @return Saved token after last page.
   * @throws IOException if file is not found
   */
  public static String fetchChanges(String savedStartPageToken) throws IOException {

        /*Load pre-authorized user credentials from the environment.
        TODO(developer) - See https://developers.google.com/identity for
        guides on implementing OAuth2 for your application.*/
    GoogleCredentials credentials = GoogleCredentials.getApplicationDefault()
        .createScoped(Arrays.asList(DriveScopes.DRIVE_FILE));
    HttpRequestInitializer requestInitializer = new HttpCredentialsAdapter(
        credentials);

    // Build a new authorized API client service.
    Drive service = new Drive.Builder(new NetHttpTransport(),
        GsonFactory.getDefaultInstance(),
        requestInitializer)
        .setApplicationName("Drive samples")
        .build();
    try {
      // Begin with our last saved start token for this user or the
      // current token from getStartPageToken()
      String pageToken = savedStartPageToken;
      while (pageToken != null) {
        ChangeList changes = service.changes().list(pageToken)
            .execute();
        for (com.google.api.services.drive.model.Change change : changes.getChanges()) {
          // Process change
          System.out.println("Change found for file: " + change.getFileId());
        }
        if (changes.getNewStartPageToken() != null) {
          // Last page, save this token for the next polling interval
          savedStartPageToken = changes.getNewStartPageToken();
        }
        pageToken = changes.getNextPageToken();
      }

      return savedStartPageToken;
    } catch (GoogleJsonResponseException e) {
      // TODO(developer) - handle error appropriately
      System.err.println("Unable to fetch changes: " + e.getDetails());
      throw e;
    }
  }
}

Python

drive/snippets/drive-v3/change_snippet/fetch_changes.py

GitHub पर देखना

import google.auth
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError


def fetch_changes(saved_start_page_token):
  """Retrieve the list of changes for the currently authenticated user.
      prints changed file's ID
  Args:
      saved_start_page_token : StartPageToken for the current state of the
      account.
  Returns: saved start page token.

  Load pre-authorized user credentials from the environment.
  TODO(developer) - See https://developers.google.com/identity
  for guides on implementing OAuth2 for the application.
  """
  creds, _ = google.auth.default()
  try:
    # create drive api client
    service = build("drive", "v3", credentials=creds)

    # Begin with our last saved start token for this user or the
    # current token from getStartPageToken()
    page_token = saved_start_page_token
    # pylint: disable=maybe-no-member

    while page_token is not None:
      response = (
          service.changes().list(pageToken=page_token, spaces="drive").execute()
      )
      for change in response.get("changes"):
        # Process change
        print(f'Change found for file: {change.get("fileId")}')
      if "newStartPageToken" in response:
        # Last page, save this token for the next polling interval
        saved_start_page_token = response.get("newStartPageToken")
      page_token = response.get("nextPageToken")

  except HttpError as error:
    print(f"An error occurred: {error}")
    saved_start_page_token = None

  return saved_start_page_token


if __name__ == "__main__":
  # saved_start_page_token is the token number
  fetch_changes(saved_start_page_token=209)

PHP

drive/snippets/drive_v3/src/DriveFetchChanges.php

GitHub पर देखना

use Google\Client;
use Google\Service\Drive;
# TODO - PHP client currently chokes on fetching start page token
function fetchChanges()
{
    try {
        $client = new Client();
        $client->useApplicationDefaultCredentials();
        $client->addScope(Drive::DRIVE);
        $driveService = new Drive($client);
        # Begin with our last saved start token for this user or the
        # current token from getStartPageToken()
        $savedStartPageToken = readLine("Enter Start Page Token: ");
        $pageToken = $savedStartPageToken;
        while ($pageToken != null) {
            $response = $driveService->changes->listChanges($pageToken, array(
                'spaces' => 'drive'
            ));
            foreach ($response->changes as $change) {
                // Process change
                printf("Change found for file: %s", $change->fileId);
            }
            if ($response->newStartPageToken != null) {
                // Last page, save this token for the next polling interval
                $savedStartPageToken = $response->newStartPageToken;
            }
            $pageToken = $response->nextPageToken;
        }
        echo $savedStartPageToken;
    } catch(Exception $e) {
        echo "Error Message: ".$e;
    }

}
require_once 'vendor/autoload.php';

.NET

drive/snippets/drive_v3/DriveV3Snippets/FetchChanges.cs

GitHub पर देखना

using Google.Apis.Auth.OAuth2;
using Google.Apis.Drive.v3;
using Google.Apis.Services;

namespace DriveV3Snippets
{
    // Class to demonstrate use-case of Drive's fetch changes in file.
    public class FetchChanges
    {
        /// <summary>
        /// Retrieve the list of changes for the currently authenticated user.
        /// prints changed file's ID
        /// </summary>
        /// <param name="savedStartPageToken">last saved start token for this user.</param>
        /// <returns>saved token for the current state of the account, null otherwise.</returns>
        public static string DriveFetchChanges(string savedStartPageToken)
        {
            try
            {
                /* Load pre-authorized user credentials from the environment.
                 TODO(developer) - See https://developers.google.com/identity for
                 guides on implementing OAuth2 for your application. */
                GoogleCredential credential = GoogleCredential.GetApplicationDefault()
                    .CreateScoped(DriveService.Scope.Drive);

                // Create Drive API service.
                var service = new DriveService(new BaseClientService.Initializer
                {
                    HttpClientInitializer = credential,
                    ApplicationName = "Drive API Snippets"
                });

                // Begin with our last saved start token for this user or the
                // current token from GetStartPageToken()
                string pageToken = savedStartPageToken;
                while (pageToken != null)
                {
                    var request = service.Changes.List(pageToken);
                    request.Spaces = "drive";
                    var changes = request.Execute();
                    foreach (var change in changes.Changes)
                    {
                        // Process change
                        Console.WriteLine("Change found for file: " + change.FileId);
                    }

                    if (changes.NewStartPageToken != null)
                    {
                        // Last page, save this token for the next polling interval
                        savedStartPageToken = changes.NewStartPageToken;
                    }
                    pageToken = changes.NextPageToken;
                }
                return savedStartPageToken;
            }
            catch (Exception e)
            {
                // TODO(developer) - handle error appropriately
                if (e is AggregateException)
                {
                    Console.WriteLine("Credential Not found");
                }
                else
                {
                    throw;
                }
            }
            return null;
        }
    }
}

Node.js

drive/snippets/drive_v3/change_snippets/fetch_changes.js

GitHub पर देखना

/**
 * Retrieve the list of changes for the currently authenticated user.
 * @param {string} savedStartPageToken page token got after executing fetch_start_page_token.js file
 **/
async function fetchChanges(savedStartPageToken) {
  // Get credentials and build service
  // TODO (developer) - Use appropriate auth mechanism for your app

  const {GoogleAuth} = require('google-auth-library');
  const {google} = require('googleapis');

  const auth = new GoogleAuth({
    scopes: 'https://www.googleapis.com/auth/drive.readonly',
  });
  const service = google.drive({version: 'v3', auth});
  try {
    let pageToken = savedStartPageToken;
    do {
      const res = await service.changes.list({
        pageToken: savedStartPageToken,
        fields: '*',
      });
      res.data.changes.forEach((change) => {
        console.log('change found for file: ', change.fileId);
      });
      pageToken = res.data.newStartPageToken;
      return pageToken;
    } while (pageToken);
  } catch (err) {
    // TODO(developer) - Handle error
    throw err;
  }
}

रिस्पॉन्स में मौजूद changes कलेक्शन में एक nextPageToken हो सकता है. अगर nextPageToken सूची में है, तो इसका इस्तेमाल बदलावों के अगले पेज को इकट्ठा करने के लिए किया जा सकता है. अगर यह सूची में नहीं है, तो क्लाइंट ऐप्लिकेशन को आने वाले समय में इस्तेमाल करने के लिए, रिस्पॉन्स में newStartPageToken को सेव करना चाहिए. पेज टोकन सेव होने के बाद, क्लाइंट ऐप्लिकेशन आने वाले समय में होने वाले बदलावों के लिए फिर से क्वेरी करने के लिए तैयार हो जाता है.

सूचनाएं पाएं

बदलाव लॉग में अपडेट की सदस्यता लेने के लिए, changes.watch तरीके का इस्तेमाल करें. सूचनाओं में बदलावों के बारे में जानकारी शामिल नहीं होती. इसके बजाय, वे यह दिखाते हैं कि नए बदलाव उपलब्ध हैं. असल बदलावों को वापस पाने के लिए, बदलाव पाना में बताए गए तरीके से बदलाव फ़ीड को पोल करें.

ध्यान दें: इस तरीके के बारे में changes.watch में जानकारी नहीं दी गई है. हालांकि, इसके लिए changes.list जैसे pageToken पैरामीटर की ज़रूरत होती है. इसे changes.getStartPageToken से वापस पाया जा सकता है.

ज़्यादा जानकारी के लिए, संसाधन में हुए बदलावों के बारे में सूचनाएं लेख पढ़ें.