google-apps-script - 如何使用谷歌应用程序脚本发送电子邮件草稿

Question

我正在使用 Google 应用程序脚本，并希望创建一个脚本，该脚本从草稿中提取邮件并在它们具有“明天发送”标签时发送它们。
查找带有特定标签的草稿非常简单:

 var threads = GmailApp.search('in:draft label:send-tomorrow');

但是我没有看到发送消息的 API!
我看到的唯一选择是:
- 打开消息
- 提取正文/附件/标题/从/到/抄送/密件抄送
- 使用上述参数发送一条新消息
- 销毁之前的草稿

这看起来很烦人，我不确定嵌入图像、多个附件等是否能很好地工作......

任何提示？

Answer 1

The only option I see is to: - open the message - extract body/attachments/title/from/to/cc/bcc - send a new message with the above params - destroy the previous draft

这是 this blog的确切主题作者:阿米特·阿加拉瓦尔他的脚本只是按照您的描述执行，但不处理内嵌图像。对于那些，您可以修改来自 this article 的代码。 .

但你是对的 - 如果你不能只发送愚蠢的东西，那么即使有一个草稿消息又有什么意义呢？!

我们可以使用 GMail API Users.drafts: send从 Google Apps 脚本发送草稿。以下独立脚本执行此操作，并处理必要的授权。

脚本

完整脚本可在 this gist 中获得.

/*
 * Send all drafts labeled "send-tomorrow".
 */
function sendDayOldDrafts() {
  var threads = GmailApp.search('in:draft label:send-tomorrow');

  for (var i=0; i<threads.length; i++) {
    var msgId = threads[0].getMessages()[0].getId();
    sendDraftMsg( msgId );
  }
}


/**
 * Sends a draft message that matches the given message ID.
 * Throws if unsuccessful.
 * See https://developers.google.com/gmail/api/v1/reference/users/drafts/send.
 *
 * @param {String}     messageId   Immutable Gmail Message ID to send
 *
 * @returns {Object}               Response object if successful, see
 *                                 https://developers.google.com/gmail/api/v1/reference/users/drafts/send#response
 */
function sendDraftMsg( msgId ) {
  // Get draft message.
  var draftMsg = getDraftMsg(msgId,"json");
  if (!getDraftMsg(msgId)) throw new Error( "Unable to get draft with msgId '"+msgId+"'" );

  // see https://developers.google.com/gmail/api/v1/reference/users/drafts/send
  var url = 'https://www.googleapis.com/gmail/v1/users/me/drafts/send'
  var headers = {
    Authorization: 'Bearer ' + ScriptApp.getOAuthToken()
  };
  var params = {
    method: "post",
    contentType: "application/json",
    headers: headers,
    muteHttpExceptions: true,
    payload: JSON.stringify(draftMsg)
  };
  var check = UrlFetchApp.getRequest(url, params)
  var response = UrlFetchApp.fetch(url, params);

  var result = response.getResponseCode();
  if (result == '200') {  // OK
    return JSON.parse(response.getContentText());
  }
  else {
    // This is only needed when muteHttpExceptions == true
    var err = JSON.parse(response.getContentText());
    throw new Error( 'Error (' + result + ") " + err.error.message );
  }
}


/**
 * Gets the current user's draft messages.
 * Throws if unsuccessful.
 * See https://developers.google.com/gmail/api/v1/reference/users/drafts/list.
 *
 * @returns {Object[]}             If successful, returns an array of 
 *                                 Users.drafts resources.
 */
function getDrafts() {
  var url = 'https://www.googleapis.com/gmail/v1/users/me/drafts';
  var headers = {
    Authorization: 'Bearer ' + ScriptApp.getOAuthToken()
  };
  var params = {
    headers: headers,
    muteHttpExceptions: true
  };
  var check = UrlFetchApp.getRequest(url, params)
  var response = UrlFetchApp.fetch(url, params);

  var result = response.getResponseCode();
  if (result == '200') {  // OK
    return JSON.parse(response.getContentText()).drafts;
  }
  else {
    // This is only needed when muteHttpExceptions == true
    var error = JSON.parse(response.getContentText());
    throw new Error( 'Error (' + result + ") " + error.message );
  }
}

/**
 * Gets the draft message ID that corresponds to a given Gmail Message ID.
 *
 * @param {String}     messageId   Immutable Gmail Message ID to search for
 *
 * @returns {String}               Immutable Gmail Draft ID, or null if not found
 */
function getDraftId( messageId ) {
  if (messageId) {
    var drafts = getDrafts();

    for (var i=0; i<drafts.length; i++) {
      if (drafts[i].message.id === messageId) {
        return drafts[i].id;
      }
    }
  }

  // Didn't find the requested message
  return null;
}


/**
 * Gets the draft message content that corresponds to a given Gmail Message ID.
 * Throws if unsuccessful.
 * See https://developers.google.com/gmail/api/v1/reference/users/drafts/get.
 *
 * @param {String}     messageId   Immutable Gmail Message ID to search for
 * @param {String}     optFormat   Optional format; "object" (default) or "json"
 *
 * @returns {Object or String}     If successful, returns a Users.drafts resource.
 */
function getDraftMsg( messageId, optFormat ) {
  var draftId = getDraftId( messageId );

  var url = 'https://www.googleapis.com/gmail/v1/users/me/drafts'+"/"+draftId;
  var headers = {
    Authorization: 'Bearer ' + ScriptApp.getOAuthToken()
  };
  var params = {
    headers: headers,
    muteHttpExceptions: true
  };
  var check = UrlFetchApp.getRequest(url, params)
  var response = UrlFetchApp.fetch(url, params);

  var result = response.getResponseCode();
  if (result == '200') {  // OK
    if (optFormat && optFormat == "JSON") {
      return response.getContentText();
    }
    else {
      return JSON.parse(response.getContentText());
    }
  }
  else {
    // This is only needed when muteHttpExceptions == true
    var error = JSON.parse(response.getContentText());
    throw new Error( 'Error (' + result + ") " + error.message );
  }
}

授权

要使用 Google 的 API，我们需要为当前用户提供一个 OAuth2 token ——就像我们对高级服务所做的一样。这是使用 ScriptApp.getOAuthToken() 完成的.

将代码复制到您自己的脚本后，打开资源 -> 高级 Google 服务，打开 Google Developers Console 的链接，并为您的项目启用 Gmail API。

只要脚本包含至少一个需要用户权限的 GMailApp 方法，就会为 OAuthToken 正确设置认证范围。在这个例子中，这是由 GmailApp.search() 处理的。在 sendDayOldDrafts() ;但是为了保险起见，您可以使用 API 直接在函数中包含一个不可访问的函数调用。