firefox插件和dev/panel之间的通信

当我点击dev/面板界面中的按钮时，我需要调用高级API函数。我是这样实现的。当插件处于onReady状态时，插件将postMessage发送到panelSide。

// index.js
onReady: function() {
    // in this function you can communicate
    // with the panel document
    this.postMessage("add-on-ready", [panelSide]);
    //this.postMessage("add-on-ready2", [panelSide]); // This message may be received in logic-panel.js
}

面板将在文本区域添加收到的消息，并只需按下某个按钮即可回复插件：

//logic-panel.js
window.addEventListener("message", function(event) {
    var toAddon = event.ports[0];
    toAddon.start();
    $(document).ready(function(){
        $('#log').append(event.data + ''n');
    });
    switch(event.data){
        case "add-on-ready":
            $(document).ready(function(){
                $("#inspect").click(function(){
                    toAddon.postMessage("inspect");
                });
                $("#exit").click(function(){
                    toAddon.postMessage("exit");
                });
            });
            break;
        default:
            toAddon.postMessage("event.data = " + event.data);
            alert("event.data = " + event.data);
    }
});

加载项处理响应。如果按下"检查"按钮，那么将涉及高级API（即handleClick函数中的PageMod）：

//index.js
addonSide.onmessage = function(event) {
    console.log(event.data);
    switch(event.data){
        case "inspect":
            console.log("run inspect");
            handleClick();
            console.log("run inspect end");
            break;
        case "exit":
            console.log("push exit =(");
            break;
        default:
            MyPanel.postMessage("add-on-ready", [panelSide]);       //not work
    }
}

function handleClick() {
    console.log("xpath");
    var data = require("sdk/self").data;
    var pageMod = require('sdk/page-mod').PageMod({
        include: ['*'],
        contentScriptFile: data.url("./addonside/xpath.js"),
        onAttach: function(worker) {
            worker.on('message', function(message) {
                console.log('mouseclick: ' + message);
                ////////////////////////////////
                // this.postMessage('mouseclick: ' + message, [panelSide]); // This message not may be received in logic-panel.js
                ////////////////////////////////
            });
        }
    });
}

Q:如何在handleClick（）函数中将postMessage发送到面板？也许有一种更合适的方法可以使用dev/panel调用高级API？