Promise实现简易AMD加载器

在最新的Chrome和FF中已经 实现了Promise。有了Promise我们用数行代码即可实现一个简易AMD模式的加载器

var registry = {

    promises: { },

    resolves: { },

    getDependencyPromise: function(name) {

        if (!this.promises[name]) {

            var resolves = this.resolves;

            this.promises[name] = new Promise(function(resolve, reject) {

                resolves[name] = resolve;

            });

        }

        return this.promises[name];

    },

    resolve: function(name, value) {

        this.getDependencyPromise(name); // creates promise if necessary

        this.resolves[name](value);

        delete this.resolves[name];

    }

};



function define(name, deps, definition) {

    require(deps, function() {

        registry.resolve(name, definition.apply(this, arguments));

    });

}



function require(deps, definition) {

    var promises = deps.map(registry.getDependencyPromise, registry);

    Promise.all(promises).then(function(result) {

        definition.apply(this, result);

    });

}

使用方式如下

 

define('framework', ['component', 'library'], function(cmp, lib) {

    return { init: 'initialized:\ncomponent: ' + cmp.description +

        '\nand library: ' + lib.version};

});



require(['framework'], function(framework) {

    alert(framework.init);

});



define('library', [], function() {

    return { version: '0.0.1' };

});



define('component', ['library'], function(lib) {

    return { description: 'uses library version: ' + lib.version };

});

原文地址    http://curiosity-driven.org/amd-loader-with-promises