Dart chrome扩展：如何在onMessage发送响应？ [英] Dart chrome extension: How to send a response in onMessage?

问题描述

目前我正在使用Google的Dart开发Chrome扩充功能。

使用的Chrome软件包： API参考〜 OnMessageEvent参考

在后台脚本中我调用： / p>

  import'package：chrome / chrome_ext.dart'as chrome; 
 
 
 void main（）{
 // ... 
 // Binde事件监听器
 chrome.runtime.onMessage.listen（onMessage） ; 
 // ... 
} 
 
 / ** 
 *消息事件处理
 * / 
 bool onMessage（chrome.OnMessageEvent messageEvent ）{
 
 JsObject message = messageEvent.message; 
 JsFunction response = messageEvent.sendResponse; 
 
 switch（message ['action']）{
 
 // ... 
 
 //由弹出式窗口使用
 case' refresh'：
 print（'Refresh called！'）; 
 chrome.storage.sync.get（）。then（（_）{
 new JsObject（response，[new JsObject.jsify（{'done'：true}）]）; 
 }）; 
 
 //请求异步发送响应（所以在OnMessageEvent参考中说）
 return true; 
 
 // ... 
} 
 
 return false; 
} 
  

我的弹出式脚本如下所示：

chrome.runtime.sendMessage（{
'action'：refresh）;

  
}）。然后（（_）{
 print（'receive response！'）; 
}）; 
 // ... 
  

工作：
消息refresh从弹出脚本发送到后台脚本工程！
后台脚本打印刷新调用！

无效：
弹出窗口脚本从不会收到从后台脚本调用的响应： new JsObject（response，[new JsObject.jsify（{'done'：true}）] / code>。

我不知道如何处理sendResponse以真正发送响应。也许我的JsObject调用是错误的？希望别人能帮忙。
（Btw。也是非异步响应在这里不起作用）

---

上 github.com/dart-gde/chrome.dart 。您的问题可能是您尝试将回复传回的方式：

解决方案

b

  new JsObject（response，[new JsObject.jsify（{'done'：true}）]）; 
  

根据 dart.js docs，函数应该在以下情况下调用：

< pre class =lang-dart prettyprint-override> response.apply（[new JsObject.jsify（{'done'：true}）]）;


---

更新：这里的工作代码：

background.dart

  import dart： js'; 
 
 void main（）{
 print（main（）...）; 
 context ['chrome'] ['runtime'] ['onMessage']。callMethod（'addListener'，[onMessageListener]）; 
} 
 
 void onMessageListener（request，sender，sendResponse）{
 print（received action = $ {request ['action']}）; 
 sendResponse.apply（[new JsObject.jsify（{'done'：true}）]）; 
} 
  

popup.dart

< pre class =lang-dart prettyprint-override> import'dart：js';

void main（）{
print（main（）：...）;
context ['chrome'] ['runtime']。callMethod（'sendMessage'，[new JsObject.jsify（{'action'：'refresh'}），（response）=> print {response ['done']}）]）;
}


---

更新：使它在JavaScript中工作

如注释中所述，从 context ['chrome'] ['runtime '] ['onMessage'] ...如果不是 JsObject ，应该使用 new JsObject.fromBrowserObject（）

  var jsObject = context ['chrome '] ['runtime'] ['onMessage']; 
（jsObject is JsObject？jsObject：new JsObject.fromBrowserObject（jsObject））
 .callMethod（'addListener'，[onMessageListener]）; 
  

希望它有帮助; - ）

right now I'm developing a Chrome extension with Google's Dart. All works fine, except the onMessage-handling.

Chrome-Package used: API Ref. ~ OnMessageEvent Ref.

In the background-script i'm calling:

import 'package:chrome/chrome_ext.dart' as chrome;


void main() {
  //...
  //Binde event-listeners
  chrome.runtime.onMessage.listen(onMessage);
  //...
}

/**
 * Message event handling
 */
bool onMessage(chrome.OnMessageEvent messageEvent){

  JsObject message = messageEvent.message;
  JsFunction response = messageEvent.sendResponse;

  switch(message['action']){

    //...

    //Used by popup
    case 'refresh':
      print('Refresh called!');
      chrome.storage.sync.get().then((_){
        new JsObject(response, [new JsObject.jsify({'done': true})]);
      });

      //Idicate to send a response asynchronously (So it's said in the OnMessageEvent Ref.)
      return true;

    //...
  }

  return false;
}

My popup-scripts looks like this:

//...
chrome.runtime.sendMessage({
  'action': "refresh"
}).then((_){
  print('receiving response!');
});
//...

What is working: The message 'refresh' send from popup-script to background-script works! The background-script prints Refresh called!

What is not working: The popup-script never receives the response called from the background-script: new JsObject(response, [new JsObject.jsify({'done': true})]);.

I don't know how to handel sendResponse to really send an response. Maybe my call with JsObject is wrong? Hope someone else can help. (Btw. also a non async-response doesn't work here)

---

This problem is also open on github.com/dart-gde/chrome.dart.

解决方案

Your problem might be in a way how you try to send the response back:

new JsObject(response, [new JsObject.jsify({'done': true})]);

According to the dart.js docs, the function should in your case be invoked like:

response.apply([new JsObject.jsify({'done': true})]);

---

Update: here the working code:

background.dart

import 'dart:js';

void main() {
  print("main()...");
  context['chrome']['runtime']['onMessage'].callMethod('addListener', [onMessageListener]);
}

void onMessageListener(request, sender, sendResponse) {
  print("received action = ${request['action']}");
  sendResponse.apply([new JsObject.jsify({'done': true})]);
}

popup.dart

import 'dart:js';

void main() {
  print("main():...");
  context['chrome']['runtime'].callMethod('sendMessage', [new JsObject.jsify({'action': 'refresh'}), (response) => print("received ${response['done']}")]);
}

---

Update: required patch to make it working in JavaScript too

As mentioned in comments, there is a problem with the returned object from context['chrome']['runtime']['onMessage'] ... If it is not JsObject it should be wrapped into it by using new JsObject.fromBrowserObject()

var jsObject = context['chrome']['runtime']['onMessage'];
(jsObject is JsObject ? jsObject : new JsObject.fromBrowserObject(jsObject))
.callMethod('addListener', [onMessageListener]);

Hope it helps ;-)

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