事件触发的 Javascript 函数 - 获取目标？

Question

我正在使用 Youtube Javascript API，但它甚至可能不是与此 API 直接相关的问题。

ytplayer.addEventListener("onStateChange", "foo");

如果“ytplayer”的状态改变，foo 被执行!

function foo() {
    //how to get "ytplayer" in here?
}

是否可以在 foo() 函数中查询是什么触发了 foo() 函数？听起来很奇怪，很难解释。试想一下，我有多个 ytplayer，例如 ytplayer1、ytplayer2 等，并且每个视频在其状态发生变化后都会触发相同的 foo() 函数。

是否可以检索哪个 ytplayer 在 foo() 函数内触发了 foo() 函数？对不起，我无法解释得更好! :)

编辑:

只是让你明白我在做什么!

/*Control Youtube videos with swfobject*/
function onYouTubePlayerReady() {
    var $ytid = '',
        ytid = '';
    $('object[id^="ytplayer_"]').each(function() {
        $ytid = $(this).attr('id');
        ytid = document.getElementById($ytid);
        ytid.addEventListener("onStateChange", "(function(status){foo(status,"+$ytid+");})");
        ytid.unMute(); 
        ytid.setVolume(100);
    });
};

function foo( status, player ) {
    console.log(status);
    console.log(player);
    //var pl = player;
}

Answer 1

似乎唯一可用的参数表示状态。

由于您似乎传递了一个已求值的字符串，因此您可能需要为每个字符串创建一个单独的函数:

function foo( status, player ) {
    // do something with status and player
}

ytplayer1.addEventListener("onStateChange", "foo1");
function foo1( status ) {
    foo( status, ytplayer1 );
}

ytplayer2.addEventListener("onStateChange", "foo2");
function foo2( status ) {
    foo( status, ytplayer2 );
}

ytplayer3.addEventListener("onStateChange", "foo3");
function foo3( status ) {
    foo( status, ytplayer3 );
}

或者您可以尝试传递整个匿名函数字符串:

function foo( status, player ) {
    // do something with status and player
}

ytplayer1.addEventListener("onStateChange", "(function(status){foo(status,ytplayer1);})");

ytplayer2.addEventListener("onStateChange", "(function(status){foo(status,ytplayer2);})");

ytplayer3.addEventListener("onStateChange", "(function(status){foo(status,ytplayer3);})");    

---

编辑: *在命名空间中创建唯一函数的通用示例。

    // gets called by the namespaced functions
function foo( status, player ) {
    // do something with status and player
}

  // create some namespace
window.myNamespace = {};

  // this gets called to create a new function in the namespace,
  //     and call addEventListener, which references the proper function
function funcFactory( player, i ) {

        // create a new function in myNamespace
    window.myNamespace[ "foo" + i ] = function( status ) {
        foo( status, player );
    };
        // Add event listener that calls that function
    player.addEventListener( "onStateChange", "window.myNamespace.foo" + i );
}

   // your loop
for( var i = 1; i < 10; i++ ) {
    var playa = someGeneratedPlayer();
    funcFactory( playa, i );
}