如何在通过 GET 请求发送之前使用 JavaScript 获取 Gmail 附件

Question

目前我正在开发 Chrome 扩展程序，我想要特定的电子邮件（即 message_id=1543c2a6347d984c）附件数据。我收到了电子邮件 message_id 还获得了附件文件名（即 abc.zip），但如何获取该附件并使用 Ajax 将其发送回我的服务器。

function getAttachments(userId, message, callback) {
  var parts = message.payload.parts;
  for (var i = 0; i < parts.length; i++) {
    var part = parts[i];
    if (part.filename && part.filename.length > 0) {
      var attachId = part.body.attachmentId;
      var request = gapi.client.gmail.users.messages.attachments.get({
        'id': attachId,
        'messageId': message.id,
        'userId': userId
      });
      request.execute(function(attachment) {
        callback(part.filename, part.mimeType, attachment);
      });
    }
  }
}

打电话

var userId="xyz@gmail.com"
    var message_id="1543c2a6347d984d";

    getAttachments(userId,message_id,function callback(filename,minetype,attachment){

console.log('File Name is '+filename);
console.log('MimeType is '+minetype);   
});

错误： main.js:15 Uncaught TypeError: Cannot read property 'parts' of undefined (function getAttachments line 2)

Answer 1

你的message_id是一个字符串，然后你调用getAttachments方法并将它作为第二个参数传递，在getAttachments中，你调用message.payload.parts，这意味着你想从一个字符串中获取一个属性payload当然是undefined。

在Users.messages.get 和Users.messages.attachments.get 进行抢劫，您需要先获取消息，然后从中获取附件。

function getAttachments(userId, message, callback) {
  var parts = message.payload.parts;
  for (var i = 0; i < parts.length; i++) {
    var part = parts[i];
    if (part.filename && part.filename.length > 0) {
      var attachId = part.body.attachmentId;
      var request = gapi.client.gmail.users.messages.attachments.get({
        'id': attachId,
        'messageId': message.id,
        'userId': userId
      });
      request.execute(function(attachment) {
        callback(part.filename, part.mimeType, attachment);
      });
    }
  }
}

function getMessage(userId, messageId, callback) {
  var request = gapi.client.gmail.users.messages.get({
    'userId': userId,
    'id': messageId
  });
  request.execute(function(message) {
      callback(userId, message);
  });
}

var userId="xyz@gmail.com"
var message_id="1543c2a6347d984d";

getMessage(userId, message_id, function(userId, message) {
    getAttachments(userId, message, function(filename,minetype,attachment) {
        console.log('File Name is '+filename);
        console.log('MimeType is '+minetype);   
    });
});