Question

我正在尝试在我的网站上用JavaScript实现Google Picker和Google Drive API。目前，我使用PHP脚本来获取Google云端硬盘文档，但是它使用的是受限范围，并且我想从应用程序中删除受限范围。

首先，我得到了Google Picker quickstart code working。我尝试使用在Google Picker代码中获取的访问令牌添加Google Drive get。 Google云端硬盘代码会出现在client.js中，对吗？ api.js中使用的访问令牌是否与client.js使用的访问令牌兼容？

我找到了an old Gist from six years ago，并试图对其进行集成和更新。现在是我的代码。 gapi.client.drive.files.get无法获取文件。

// Scope to use to access user's photos.
var scope = 'https://www.googleapis.com/auth/drive.file';

var pickerApiLoaded = false;
var driveApiLoaded = false;
var oauthToken;

// Use the API Loader script to load google.picker and gapi.auth.
function onApiLoad() {
    gapi.load('auth2', onAuthApiLoad);
    gapi.load('picker', onPickerApiLoad);
}

function onClientLoad() {
    gapi.client.setApiKey(developerKey);
    gapi.client.load('drive', 'v2', onDriveApiLoad);
}

function onAuthApiLoad() {
    var authBtn = document.getElementById('auth');
    authBtn.disabled = false;
    authBtn.addEventListener('click', function() {
        gapi.auth2.init({ client_id: clientId }).then(function(googleAuth) {
            googleAuth.signIn({ scope: scope }).then(function(result) {
                handleAuthResult(result.getAuthResponse());
            })
        })
    });
}

function onPickerApiLoad() {
    pickerApiLoaded = true;
    createPicker();
}

function onDriveApiLoad() {
    driveApiLoaded = true;
}

function handleAuthResult(authResult) {
    if (authResult && !authResult.error) {
        oauthToken = authResult.access_token;
        createPicker();
    }
}

// Create and render a Picker object for picking user Photos.
function createPicker() {
    if (pickerApiLoaded && oauthToken) {
        var view = new google.picker.DocsView(google.picker.ViewId.SPREADSHEETS);
        //view.setMimeTypes("text/csv");
        //view.setMode(google.picker.DocsViewMode.LIST);
        view.setQuery(jQuery('[updateparam="name"]').val());

        var picker = new google.picker.PickerBuilder().
                //addView(google.picker.ViewId.DOCS).
                addView(view).
                setInitialView(view).
                setOAuthToken(oauthToken).
                setDeveloperKey(developerKey).
                setCallback(pickerCallback).
                build();
        picker.setVisible(true);
    }
}

// A simple callback implementation.
function pickerCallback(data) {
    if (data[google.picker.Response.ACTION] == google.picker.Action.PICKED) {
        var doc = data[google.picker.Response.DOCUMENTS][0];
        var fileId = doc[google.picker.Document.ID];
        jQuery('[updateparam="googleDriveFileId"]').val(fileId);

        //if (driveApiLoaded) {
            var request = gapi.client.drive.files.get({
                'fileId': fileId
            });
            request.execute(function(file) {
                var xhr = new XMLHttpRequest();
                xhr.open('GET', file.downloadUrl);
                xhr.setRequestHeader('Authorization', 'Bearer ' + oauthToken);
                xhr.onload = function() {
                    console.log(xhr.responseText);
                };
                xhr.onerror = function() {
                    warningMessage.displayMessage('Failed to download Google Drive document ' + fileId);
                };          
            });
        //} else {
        //  warningMessage.displayMessage('Google Drive API has not been loaded.');
        //}
    }
    // Triggers before Picker is shown
    // else {
    //  warningMessage.displayMessage('No Google Drive document selected.');
    //}
}

还有我的脚本标签：

<!-- The Google API Loader script. -->
<script type="text/javascript" src="https://apis.google.com/js/api.js?onload=onApiLoad"></script>
<script type="text/javascript" src="https://www.google.com/jsapi?key=KEY"></script>
<script type="text/javascript" src="https://apis.google.com/js/client.js?onload=onClientLoad"></script>

Answer 1

问题是，当您尝试在file.downloadUrl中检索downloadUrl属性时，该字段在Drive API版本3（该版本2中已不存在）中不再存在，请检查v2 [1]和v3 [2]。

相反，您应该使用webContentLink属性下载文件，该文件可用于具有二进制内容（如图像，pdf等）的文件，但不适用于google docs和工作表（仅适用于webViewLink属性，该属性是指向文件）[2]。对于这些情况（文档和表格），您可以实施import方法，该方法适用于转换google文档并返回文件对象[3]。导入请求将如下所示：

var request = gapi.client.drive.files.import({ 'fileId': fileId, 'mimeType': mimeType });

使用mimeType作为所需的目标文档（pdf，txt等）。然后，与其他情况一样，在回调内部，使用file.webContentLink访问属性。

[1] https://developers.google.com/drive/api/v2/reference/files

[2] https://developers.google.com/drive/api/v3/reference/files

[3] https://developers.google.com/drive/api/v3/reference/files/export

Answer 2

通过反复试验，我发现为了同时加载Google Picker（client：auth2）和Google Drive API（gapi.client），必须先使用回调初始化Google Picker，然后再初始化Google Drive使用必须链接的Promise初始化API。如果Promise没有链接，那么它将无法解决并且将无法工作。

// Use the Google API Loader script to load the google.picker script.
function loadPicker() {
    gapi.load('auth', {'callback': onAuthApiLoad});
    gapi.load('picker', {'callback': onPickerApiLoad});
}

function onAuthApiLoad() {
    driveApiLoaded = true;
}

function onPickerApiLoad() {
    pickerApiLoaded = true;
}

function askForClientAuthorization() {
    gapi.load('client:auth2', function(_) {
        window.gapi.client.init({
            apiKey: developerKey,
            clientId: clientId,
            discoveryDocs: ["https://www.googleapis.com/discovery/v1/apis/drive/v3/rest"],
            scope: 'https://www.googleapis.com/auth/drive.file'
        })
        .then(function(__) {
            return gapi.client.drive.files.export({
                'fileId': window.googleDriveFileId,
                'mimeType': 'text/csv'
            })
            .then(function(file) {
                // Client is authorized to access this file, do something with the file
            })
            .catch(function(e) {
                gapi.auth.authorize(
                {
                    'client_id': clientId,
                    'scope': scope,
                    'immediate': false
                },
                handleAuthResult);
            });

        })
    })
}

function handleAuthResult(authResult) {
    if (authResult && !authResult.error) {
        oauthToken = authResult.access_token;
        createPicker();
        return true;
    } else {
        return false;
    }
}

// Create and render a Picker object for searching images.
function createPicker() {
    if (pickerApiLoaded && oauthToken) {
        var view = new google.picker.DocsView(google.picker.ViewId.SPREADSHEETS);
        view.setMode(google.picker.DocsViewMode.LIST);
        view.setQuery(window.dataFeedName);
        var picker = new google.picker.PickerBuilder()
                .setAppId(appId)
                .setOAuthToken(oauthToken)
                .addView(view)
                .setDeveloperKey(developerKey)
                .setCallback(pickerCallback)
                .build();
         picker.setVisible(true);
         return picker;
    }
}

// A simple callback implementation.
function pickerCallback(data) {
    if (data[google.picker.Response.ACTION] == google.picker.Action.PICKED) {
        // Do work
    }
}

使用此代码，它必须检查用户是否有权执行每次执行。

如何使用JavaScript在Google Picker中下载Google表格？

2 个答案: