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我决定为 Firefox 开发一个插件来控制Kodi，因为我找不到任何已经完成了我想要的一切的插件。我选择使用WebSocket与 Kodi 通信，以便接收事件，但在实现我的附加组件的 WebSocket 部分时遇到问题。暂时，我创建了一个带有页面工作者的附加组件，专门用于测试 WebSocket 功能。我的开发插件和临时测试插件都表现出以下行为：

如果我test.html在插件之外的 Firefox 中直接加载（内容见文章底部），WebSocket 将按预期工作。当我播放或暂停 Kodi 时，连接保持打开并接收事件：

在附加组件之外运行 test.html 的控制台输出

Connection opened test.html:12:9
Object { jsonrpc: "2.0", method: "Player.OnPlay", params: Object } test.html:28:9
Object { jsonrpc: "2.0", method: "Player.OnPause", params: Object } test.html:28:9
Object { jsonrpc: "2.0", method: "Player.OnPlay", params: Object } test.html:28:9
Object { jsonrpc: "2.0", method: "Player.OnPause", params: Object } test.html:28:9
Object { jsonrpc: "2.0", method: "Player.OnPlay", params: Object } test.html:28:9
Object { jsonrpc: "2.0", method: "Player.OnPause", params: Object } test.html:28:9
Object { jsonrpc: "2.0", method: "GUI.OnScreensaverActivated", params: Object } test.html:28:9

但是，在使用jpm run. 连接在几秒钟后关闭（最多四秒钟）。（请注意，在连接打开期间我可以很好地接收事件）：

使用 jpm 运行附加组件的控制台输出

C:\Users\User\Desktop\example>jpm run
JPM [info] Starting jpm run on test
JPM [info] Creating a new profile
console.log: test: Connection opened
console.log: test: {"jsonrpc":"2.0","method":"Player.OnPlay","params":{"data":{"item":{"id":23,"type":"song"},"player":{"playerid":0,"speed":1}},"sender":"xbmc"}}
console.log: test: {"jsonrpc":"2.0","method":"Player.OnPause","params":{"data":{"item":{"id":23,"type":"song"},"player":{"playerid":0,"speed":0}},"sender":"xbmc"}}
console.log: test: Websocket error: undefined
console.log: test: Connection closed: 1006

如何找出连接在插件内部而不是插件外部的原因？我该如何纠正这种奇怪的行为？

index.js：

var data = require("sdk/self").data;
var pageWorker = require("sdk/page-worker");

var pw = pageWorker.Page({
  contentURL: data.url('test.html')
});

pw.port.on('message', function(message) {
  console.log(message);
});

测试.html：

<!DOCTYPE html>
<html lang="en-US">
  <head>
  <meta http-equiv="content-type" content="text/html; charset=utf-8">
    <script type=text/javascript>
    var ws = new WebSocket('ws://192.168.2.34:9090/jsonrpc');

    ws.onopen = function (event) {
      try {
        addon.port.emit('message', "Connection opened");
      } catch (e) {
        console.log("Connection opened");
      }
    };

    ws.onerror = function (event) {
      try {
        addon.port.emit('message', "Websocket error: "+event.data);
      } catch (e) {
        console.log("Websocket error: "+event.data);
      }
    };

    ws.onmessage = function (event) {
      try {
        addon.port.emit('message', JSON.parse(event.data));
      } catch (e) {
        console.log(JSON.parse(event.data));
      }
    };

    ws.onclose = function (event) {
      try {
        addon.port.emit('message', "Connection closed: "+event.code);
      } catch (e) {
        console.log("Connection closed: "+event.code);
      }
    };
    </script>
  </head>
  <body>
  </body>
</html>
4

1 回答 1

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我安装了 Wireshark 并发现在插件内部运行时正在发送 Websocket ping 请求，但不在插件外部运行。Kodi 无法用 pong 响应 ping，因此 Firefox 关闭了连接。

有趣的是，来自插件内部的延迟和后续连接似乎没有生成 ping 请求，因此不会关闭。因此，解决方案是在连接关闭时简单地延迟或重新打开连接（无论如何处理网络连接丢失都是一件好事）。

测试.html

<!DOCTYPE html>
<html lang="en-US">
  <head>
  <meta http-equiv="content-type" content="text/html; charset=utf-8">
    <script type=text/javascript>

    //connect(); //generates a ping request
    setTimeout(connect, 10000); //doesn't generate a ping request
    
    function connect() {
      this.ws = new WebSocket('ws://192.168.2.34:9090/jsonrpc');

      this.ws.onopen = function (event) {
        try {
          addon.port.emit('message', "Connection opened");
        } catch (e) {
          console.log("Connection opened");
        }
      };
      
      this.ws.onerror = function (event) {
        try {
          addon.port.emit('message', "Websocket error: "+event.data);
        } catch (e) {
          console.log("Websocket error: "+event.data);
        }
      };
      
      this.ws.onmessage = function (event) {
        try {
          addon.port.emit('message', JSON.parse(event.data));
        } catch (e) {
          console.log(JSON.parse(event.data));
        }
      };
      
      this.ws.onclose = function (event) {
        try {
          addon.port.emit('message', "Connection closed: "+event.code);
        } catch (e) {
          console.log("Connection closed: "+event.code);
        }
        setTimeout(connect, 5000); //re-opens connection, doesn't generate a ping request
      };
    }
    </script>
  </head>
  <body>
  </body>
</html>
于 2016-04-06T05:25:38.650 回答