如何使用JavaScript通過GET請求之前發送

Question

目前我正在Chrome擴展我想特別是電子郵件（即MESSAGE_ID = 1543c2a6347d984c）附件數據獲取Gmail附件。我得到了email message_id也獲得了附件文件名（即abc.zip），但是如何獲得該附件並使用Ajax發送回我的服務器。

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); 
     }); 
    } 
    } 
} 

調用

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); 
}); 

錯誤： main.js：15遺漏的類型錯誤：無法讀取的未定義的屬性 '零件'（功能getAttachments 2號線）

Answer 1

你MESSAGE_ID是字符串，然後你調用getAttachments方法並將其作爲第二個參數傳遞，在getAttachments中，你調用message.payload.parts，這意味着你想得到一個屬性​​，當然是undefined。

拿着贓物Users.messages.get和Users.messages.attachments.get，您需要先收到消息，然後從中獲取附件。

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); 
    }); 
});