Menggunakan fitur Google Picker API di aplikasi web

Dokumen ini menjelaskan cara menggunakan fitur Google Picker API seperti mengaktifkan pemilihan beberapa item, menyembunyikan panel navigasi, dan memilih akun pengguna dengan token OAuth 2.0 aplikasi saat ini.

Prasyarat

Untuk contoh ini, Anda harus menentukan beberapa item:

  • Untuk menemukan Client ID dan API Key:

    1. Di konsol Google Cloud, buka Menu > APIs & Services > Credentials.

      Buka Kredensial

  • Untuk menemukan App ID:

    1. Di konsol Google Cloud, buka Menu > IAM & Admin > Settings.

      Buka Setelan

    2. Gunakan project number untuk ID aplikasi.

Project Google Cloud yang sama harus berisi client ID dan app ID karena digunakan untuk mengotorisasi akses ke file pengguna.

Membuat aplikasi

Contoh kode berikut menunjukkan cara menggunakan pemilih gambar atau halaman upload yang dapat dibuka pengguna dari tombol di aplikasi web.

drive/picker/helloworld.html
<!DOCTYPE html>
<html>
<head>
  <title>Google Picker API Quickstart</title>
  <meta charset="utf-8" />
</head>
<body>
<p>Google Picker API Quickstart</p>

<!--Add buttons to initiate auth sequence and sign out.-->
<button id="authorize_button" onclick="handleAuthClick()">Authorize</button>
<button id="signout_button" onclick="handleSignoutClick()">Sign Out</button>

<pre id="content" style="white-space: pre-wrap;"></pre>

<script type="text/javascript">
  /* exported gapiLoaded */
  /* exported gisLoaded */
  /* exported handleAuthClick */
  /* exported handleSignoutClick */

  // Authorization scopes required by the API; multiple scopes can be
  // included, separated by spaces.
  const SCOPES = 'https://www.googleapis.com/auth/drive.metadata.readonly';

  // TODO(developer): Replace with your client ID and API key from https://console.cloud.google.com/.
  const CLIENT_ID = '<YOUR_CLIENT_ID>';
  const API_KEY = '<YOUR_API_KEY>';

  // TODO(developer): Replace with your project number from https://console.cloud.google.com/.
  const APP_ID = '<YOUR_APP_ID>';

  let tokenClient;
  let accessToken = null;
  let pickerInited = false;
  let gisInited = false;

  document.getElementById('authorize_button').style.visibility = 'hidden';
  document.getElementById('signout_button').style.visibility = 'hidden';

  /**
   * Callback after api.js is loaded.
   */
  function gapiLoaded() {
    gapi.load('client:picker', initializePicker);
  }

  /**
   * Callback after the API client is loaded. Loads the
   * discovery doc to initialize the API.
   */
  async function initializePicker() {
    await gapi.client.load('https://www.googleapis.com/discovery/v1/apis/drive/v3/rest');
    pickerInited = true;
    maybeEnableButtons();
  }

  /**
   * Callback after Google Identity Services are loaded.
   */
  function gisLoaded() {
    tokenClient = google.accounts.oauth2.initTokenClient({
      client_id: CLIENT_ID,
      scope: SCOPES,
      callback: '', // defined later
    });
    gisInited = true;
    maybeEnableButtons();
  }

  /**
   * Enables user interaction after all libraries are loaded.
   */
  function maybeEnableButtons() {
    if (pickerInited && gisInited) {
      document.getElementById('authorize_button').style.visibility = 'visible';
    }
  }

  /**
   *  Sign in the user upon button click.
   */
  function handleAuthClick() {
    tokenClient.callback = async (response) => {
      if (response.error !== undefined) {
        throw (response);
      }
      accessToken = response.access_token;
      document.getElementById('signout_button').style.visibility = 'visible';
      document.getElementById('authorize_button').innerText = 'Refresh';
      await createPicker();
    };

    if (accessToken === null) {
      // Prompt the user to select a Google Account and ask for consent to share their data
      // when establishing a new session.
      tokenClient.requestAccessToken({prompt: 'consent'});
    } else {
      // Skip display of account chooser and consent dialog for an existing session.
      tokenClient.requestAccessToken({prompt: ''});
    }
  }

  /**
   *  Sign out the user upon button click.
   */
  function handleSignoutClick() {
    if (accessToken) {
      google.accounts.oauth2.revoke(accessToken);
      accessToken = null;
      document.getElementById('content').innerText = '';
      document.getElementById('authorize_button').innerText = 'Authorize';
      document.getElementById('signout_button').style.visibility = 'hidden';
    }
  }

  /**
   *  Create and render a Google Picker object for searching images.
   */
  function createPicker() {
    const view = new google.picker.View(google.picker.ViewId.DOCS);
    view.setMimeTypes('image/png,image/jpeg,image/jpg');
    const picker = new google.picker.PickerBuilder()
        .enableFeature(google.picker.Feature.NAV_HIDDEN)
        .enableFeature(google.picker.Feature.MULTISELECT_ENABLED)
        .setDeveloperKey(API_KEY)
        .setAppId(APP_ID)
        .setOAuthToken(accessToken)
        .addView(view)
        .addView(new google.picker.DocsUploadView())
        .setCallback(pickerCallback)
        .build();
    picker.setVisible(true);
  }

  /**
   * Displays the file details of the user's selection.
   * @param {object} data - Contains the user selection from the Google Picker.
   */
  async function pickerCallback(data) {
    if (data.action === google.picker.Action.PICKED) {
      let text = `Google Picker response: \n${JSON.stringify(data, null, 2)}\n`;
      const document = data[google.picker.Response.DOCUMENTS][0];
      const fileId = document[google.picker.Document.ID];
      console.log(fileId);
      const res = await gapi.client.drive.files.get({
        'fileId': fileId,
        'fields': '*',
      });
      text += `Drive API response for first document: \n${JSON.stringify(res.result, null, 2)}\n`;
      window.document.getElementById('content').innerText = text;
    }
  }
</script>
<script async defer src="https://apis.google.com/js/api.js" onload="gapiLoaded()"></script>
<script async defer src="https://accounts.google.com/gsi/client" onload="gisLoaded()"></script>
</body>
</html>

Fungsi setOAuthToken memungkinkan aplikasi menggunakan token autentikasi saat ini untuk menentukan Akun Google mana yang digunakan Google Picker untuk menampilkan file. Jika pengguna login dengan beberapa Akun Google, Google Picker dapat menampilkan file dari akun resmi yang sesuai.

Setelah mendapatkan ID file dari Google Picker saat membuka file, aplikasi kemudian dapat mengambil metadata file dan mendownload konten file seperti yang dijelaskan dalam metode get resource files.