使用 Google Apps 脚本：如何转换/导出云端硬盘文件？

Question

我想使用 Google Apps 脚本将本机 Google 电子表格/文档/绘图/演示文稿文件导出到同一文件夹中的另一种格式。我已启用高级驱动器服务，并查看了在您的应用程序中打开和转换 Google 文档的说明。

希望我可以使用Export获取一个文件，然后使用Insert保存/重命名该文件。

试图实现类似的目标：

var file = {fileId: "1yDe...lD2U", 
            folderId: "0B_...hZ1k", 
            mimetype:"application/vnd.google-apps.document", 
            targetMimetype:"application/pdf", 
            targetName:"my converted document"}
var newFile = Drive.Files.export(file.fileId, file.targetMimetype)

// results in error message:
// "Export requires alt=media to download the exported content."

// I am sure the above is incomplete, but unsure how to actually
// save the exported file, in the correct location, with correct filename

更新：将 alt=media 添加到调用 ( var newFile = Drive.Files.export(file.fileId, file.targetMimetype, {alt: "media"})) 时，脚本会退出并显示错误代码 200，并在错误消息中显示 PDF 内容。与问题 6573类似。

更新：这可能还不够清楚，我想转换高级驱动页面中列出的所有格式，而不仅仅是转换为 PDF。DriveApp getAs文档指出，DriveApp 可以将大部分内容转换为 PDF 和图像。因此，重点是使用 Advanced Drive 而不是 DriveApp。

Answer 1

作为解决方法，我现在使用 OAuth2 库和直接 Drive API。

// ---------------------------------------------------------------------------------------------------
function testConvert() {
  var file = {
    id: "1cpAZp...I7ejZW1idk", // Google Sheet
    folderId: "0B_...Z1k", // test folder
  }

  convert(file, "pdf", "application/pdf");
  convert(file, "csv", "text/csv");
  convert(file, "xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
}

// ---------------------------------------------------------------------------------------------------
function convert(file, extension, targetMimeType) {
  var exportDetails = {
    targetMimeType: targetMimeType || "application/pdf",
    extension: extension || "pdf",
    postfix: "CONVERTED_FROM_GOOGLE_DOC",
  }

  // http://stackoverflow.com/questions/42887569/using-google-apps-script-how-to-convert-export-a-drive-file
  // https://code.google.com/p/google-apps-script-issues/issues/detail?id=6573

  // var blob = Drive.Files.export(file.id, exportDetails.targetMimeType, {alt: "media"})
  /*
    results in error 200 + content of converted file
    documentation https://developers.google.com/drive/v2/reference/files/export
    1) does not mention the {alt:"media"} (and without it the error is: "export requires alt=media to download the exported content")
    2) states the output is a Files resource (not a blob)
  */

  // using alternative: OAuth2 + public API
  // https://github.com/googlesamples/apps-script-oauth2
  var driveService = getDriveService();
  if (!driveService.hasAccess()) {
    showSidebar();
    return;
  }

  var accessToken = driveService.getAccessToken();
  var url = "https://www.googleapis.com/drive/v2/files/"+file.id+"/export?mimeType="+ exportDetails.targetMimeType
  var blob = UrlFetchApp.fetch(url, {
    headers: {
      Authorization: 'Bearer ' + driveService.getAccessToken()
    }
  });

  var resource = {
    title: DriveApp.getFileById(file.id).getName() +" "+ exportDetails.postfix +"."+ exportDetails.extension,
    description: "This is a converted document",
    mimeType: exportDetails.targetMimeType,
    parents: [{
      "kind": "drive#parentReference",
      "id": file.folderId,
      //"selfLink": string,
      //"parentLink": string,
      "isRoot": false
    }],
  }

  try {
    var convertedFile = Drive.Files.insert(resource, blob);
    Logger.log('ID: %s, File size (bytes): %s', convertedFile.id, convertedFile.fileSize);

  } catch(e) {
    Logger.log(e)
  }
}