摘要：消息前綴建議使用自己的項目名避免多項目之間的沖突類消息對象往發送消息出于安全考慮發送消息會帶上前綴以及現代瀏覽器支持兼容信使類添加一個消息對象初始化消息監聽剝離消息前綴兼容監聽消息廣播消息用法頁面頁面跨域傳數據跨域傳高度

/**
 *     __  ___                                                 
 *    /  |/  /___   _____ _____ ___   ____   ____ _ ___   _____
 *   / /|_/ // _  / ___// ___// _  / __  / __ `// _  / ___/
 *  / /  / //  __/(__  )(__  )/  __// / / // /_/ //  __// /    
 * /_/  /_/ \___//____//____/ \___//_/ /_/ \__, / \___//_/     
 *                                        /____/               
 * 
 * @description MessengerJS, a common cross-document communicate solution.
 * @author biqing kwok
 * @version 2.0
 * @license release under MIT license
 */
define(function (require) {
    // 消息前綴, 建議使用自己的項目名, 避免多項目之間的沖突
    var prefix = "[PROJECT_NAME]",
        supportPostMessage = "postMessage" in window;

    // Target 類, 消息對象
    function Target(target, name){
        var errMsg = "";
        if(arguments.length < 2){
            errMsg = "target error - target and name are both requied";
        } else if (typeof target != "object"){
            errMsg = "target error - target itself must be window object";
        } else if (typeof name != "string"){
            errMsg = "target error - target name must be string type";
        }
        if(errMsg){
            throw new Error(errMsg);
        }
        this.target = target;
        this.name = name;
    }

    // 往 target 發送消息, 出于安全考慮, 發送消息會帶上前綴
    if ( supportPostMessage ){
        // IE8+ 以及現代瀏覽器支持
        Target.prototype.send = function(msg){
            this.target.postMessage(prefix + msg, "*");
        };
    } else {
        // 兼容IE 6/7
        Target.prototype.send = function(msg){
            var targetFunc = window.navigator[prefix + this.name];
            if ( typeof targetFunc == "function" ) {
                targetFunc(prefix + msg, window);
            } else {
                throw new Error("target callback function is not defined");
            }
        };
    }

    // 信使類
    function Messenger(name){
        this.targets = {};
        this.name = name;
        this.listenFunc = [];
        this.initListen();
    }

    // 添加一個消息對象
    Messenger.prototype.addTarget = function(target, name){
        var targetObj = new Target(target, name);
        this.targets[name] = targetObj;
    };

    // 初始化消息監聽
    Messenger.prototype.initListen = function(){
        var self = this;
        var generalCallback = function(msg){
            if(typeof msg == "object" && msg.data){
                msg = msg.data;
            }
            // 剝離消息前綴
            msg = msg.slice(prefix.length);
            for(var i = 0; i < self.listenFunc.length; i++){
                self.listenFunc[i](msg);
            }
        };

        if ( supportPostMessage ){
            if ( "addEventListener" in document ) {
                window.addEventListener("message", generalCallback, false);
            } else if ( "attachEvent" in document ) {
                window.attachEvent("onmessage", generalCallback);
            }
        } else {
            // 兼容IE 6/7
            window.navigator[prefix + this.name] = generalCallback;
        }
    };

    // 監聽消息
    Messenger.prototype.listen = function(callback){
        this.listenFunc.push(callback);
    };

    // 廣播消息
    Messenger.prototype.send = function(msg){
        var targets = this.targets,
            target;
        for(target in targets){
            if(targets.hasOwnProperty(target)){
                targets[target].send(msg);
            }
        }
    };

    return Messenger;


});

var messenger = new Messenger("parent");
        var iframe = document.getElementById("iframepage");
        messenger.addTarget(iframe.contentWindow, "iframe");

        messenger.listen(function (msg) {
            var result = parseInt(msg, 10) + 20;

            if (result < mainWindowHeight) {
                result = mainWindowHeight;
            }
            $("#iframepage").height(result);
});

    // iframe跨域傳數據
    var messenger = new Messenger("iframe");
    messenger.addTarget(window.parent, "parent");  

    // 跨域傳main 高度
    var height = $(".main").height();
    messenger.targets["parent"].send(height);

    messenger.listen(function (msg) {

    });