Question

我已开始实施Chrome扩展程序，旨在向用户显示来自RSS Feed的链接。

浏览器操作扩展包含一个后台脚本（bg.js）和一个带有jQuery和popup.js的popup.html

据我所知，一切正常，直到应该在bg.js中调用callback()并在popup.js中收到。似乎永远不会触发popup.js中的回调。

我检查了后台页面控制台和弹出控制台......没有错误。

为了从bg.js收到repsonse，我需要更改什么？

顺便说一句：使用chrome.runtime.sendMessage和chrome.extension.sendMessage之间的区别是什么？

manifest.json看起来像

{
  "manifest_version": 2,

  "name": "heise Newsticker",
  "description": "Der RSS-Feed des heise Newstickers.",
  "version": "1.0",

  "icons": {
      "128" : "logo128.png"
  },
  "background": {
    "persistent": true,
    "scripts": ["bg.js"]
  },
  "permissions": [
    "http://www.heise.de/newsticker*",
    "http://heise.de.feedsportal.com/c/35207/f/653902/index.rss"
  ],
  "browser_action": {
    "default_icon": "logo.png",
    "default_popup": "popup.html"
  }
}

这是bg.js

function fetch_feed(url, callback) {
        var xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function(data) {
      if (xhr.readyState == 4) {
        if (xhr.status == 200 || xhr.status == 304) {
         console.log("Request successful");
          var data = xhr.responseText;
          callback(data);
        } else {
         console.log("Request not successful");
          callback(null);
        }
      }
    }
    // Note that any URL fetched here must be matched by a permission in
    // the manifest.json file!
    xhr.open('GET', url, true);
    xhr.send();
}

function onMessage(request, sender, callback) {
         console.log("onmessage received with URL: " + request.url);
        if (request.action == 'fetch_feed') {
         fetch_feed(request.url, callback);
       }
}

console.log('listener installed');
// Wire up the listener.
chrome.extension.onMessage.addListener(onMessage);

popup.html

<!DOCTYPE html>
<html>
<head>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="popup.js"></script>
</head>
<body>
<div id="ziel"></div>
</body>
</html>

最后：popup.js

$(document).ready(function() {
        fetch_feed();
});

function fetch_feed() {
         console.log("starting");
        chrome.extension.sendMessage({'action' : 'fetch_feed', 'url' : 'http://www.heise.de/newsticker/heise-atom.xml'},
                function(response) {
                        console.log("Response successfully received: " + response);
                        display_stories(response);
                }
        );
}

function display_stories(xml) {
   $('#ziel').html("<h3>now displaying</h3>");
}

Answer 1

解决方法（和简化）：我从bg.js中删除了所有内容，并将XMLHttpRequest移到了popup.js

所以没有更多的消息传递...这解决了我的问题，但问题仍然有点奇怪

popup.js和background.js之间的通信

1 个答案: