Script loader

Script.js

/*
Script("hoge.js", "huga.js", function(err, args) {
    err || console.log("script loaded");
});
 */


(function(global) {

var _loaded = {}; // { source: boolean, ... }

function Script(var_args) { // @var_args: (path, path, ... callback?)
    var args = arguments;
    var i = 0, iz = args.length;
    var callback = null;

    // detect callback
    if (typeof args[iz - 1] === "function") {
        callback = args[iz - 1];
        --iz;
    }
    var flow = new Flow(iz, callback);

    for (; i < iz; ++i) {
        load(args[i], flow);
    }
}

function load(src, flow) {
    if (src in _loaded) {
        flow.pass(); // already loaded
    } else {
        var script = document.createElement("script");

        script.onerror = function(event) {
            alert("Script load failed: " + src);
            flow.miss(src);
        };
        script.onload = function() {
            _loaded[src] = true;
            flow.pass();
        };
        script.src = src;
        (document.head || document.body).appendChild(script);
    }
}

global.Script = Script;

})(this);