rgrove/multi-yui.js

## multi-yui.js
YUI.add('multi', function (Y) {

/**
Loads different versions of YUI in sandboxed iframes and makes them available
for use in the parent frame by exposing them as properties on a `Y.Multi`
instance.

This is primarily intended to be used for testing. You probably shouldn't use it
for anything real.

@example

Load YUI 3.2.0 and make it available as `multi.YUI_320`. Load YUI 3.3.0 and
make it available as `multi.YUI_330`.

    var multi = new Y.Multi({
        seeds: {
            YUI_320: 'http://yui.yahooapis.com/3.2.0/build/yui/yui-min.js',
            YUI_330: 'http://yui.yahooapis.com/3.3.0/build/yui/yui-min.js'
        }
    });

    multi.on('ready', function () {
        multi.YUI_320().use(function (Y) {
            Y.log("OMG I'm using YUI 3.2.0!");
        });

        multi.YUI_330().use(function (Y) {
            Y.log("OMG I'm using YUI 3.3.0!");
        });
    });

@example

Load YUI 3.2.0 and 3.3.0, and instantiate both of them before firing the `ready`
event. The YUI instances, complete with `use()`ed modules attached, will be made
available on the `multi` instance.

    var multi = new Y.Multi({
        seeds: {
            Y_320: {
                url: 'http://yui.yahooapis.com/3.2.0/build/yui/yui-min.js',
                use: ['node']
            },

            Y_330: {
                url: 'http://yui.yahooapis.com/3.3.0/build/yui/yui-min.js',
                use: ['node']
            }
        }
    });

    multi.on('ready', function () {
        multi.Y_320.log("OMG I'm using YUI 3.2.0!");
        multi.Y_330.log("OMG I'm using YUI 3.3.0!");
    });

@module multi
@class Multi
@param {Object} config Config object.
    @param {Object} config.seeds Mapping of seed names to either URLs or config
        objects.
@constructor
**/

var doc = Y.config.doc;

function Multi(config) {
    this._config = Y.merge({
        seeds: {}
    }, config);

    this._iframes     = [];
    this._seedCount   = Y.Object.size(this._config.seeds);
    this._seedsLoaded = 0;

    /**
    Fired when all requested seed files have been loaded (and instantiated, if
    instantiation was requested). Subscribe to this event in order to be
    notified when you can start using the requested YUI versions.

    @event ready
    @fireOnce
    **/
    this.publish('ready', {fireOnce: true});

    Y.Object.each(this._config.seeds, this._createFrame, this);
}

Multi.prototype = {
    _createFrame: function (seed, name) {
        var iframe    = doc.createElement('iframe'),
            self      = this,
            url       = seed.url || seed,
            use       = seed.use,
            iframeDoc;

        iframe.style.display = 'none';

        this._iframes.push(iframe);
        doc.body.insertBefore(iframe, doc.body.firstChild);

        // Load the YUI seed URL into the iframe when it loads.
        iframe.onload = function () {
            // If a "use" array was passed, create a YUI instance before
            // indicating completion. Otherwise, just attach the YUI global.
            if (use) {
                self[name] = iframe.contentWindow.YUI().use(use, function () {
                    self._seedLoaded();
                });
            } else {
                self[name] = iframe.contentWindow.YUI;
                self._seedLoaded();
            }
        };

        iframeDoc = iframe.contentWindow.document;

        iframeDoc.write(
            '<!DOCTYPE html>' +
            '<html>' +
            '<head>' +
                '<meta charset="utf-8">' +
                '<title>MultiYUI: ' + name + '</title>' +
                '<script src="' + url + '"></script>' +
            '</head>' +
            '<body></body>' +
            '</html>'
        );

        // Allows window.onload to fire.
        iframeDoc.close();
    },

    _seedLoaded: function () {
        this._seedsLoaded += 1;

        if (this._seedsLoaded === this._seedCount) {
            this.fire('ready');
        }
    }
};

Y.augment(Multi, Y.EventTarget);

Y.Multi = Multi;

}, '@VERSION@', {requires: ['event-custom']});
	YUI.add('multi', function (Y) {

	/**
	Loads different versions of YUI in sandboxed iframes and makes them available
	for use in the parent frame by exposing them as properties on a `Y.Multi`
	instance.

	This is primarily intended to be used for testing. You probably shouldn't use it
	for anything real.

	@example

	Load YUI 3.2.0 and make it available as `multi.YUI_320`. Load YUI 3.3.0 and
	make it available as `multi.YUI_330`.

	var multi = new Y.Multi({
	seeds: {
	YUI_320: 'http://yui.yahooapis.com/3.2.0/build/yui/yui-min.js',
	YUI_330: 'http://yui.yahooapis.com/3.3.0/build/yui/yui-min.js'
	}
	});

	multi.on('ready', function () {
	multi.YUI_320().use(function (Y) {
	Y.log("OMG I'm using YUI 3.2.0!");
	});

	multi.YUI_330().use(function (Y) {
	Y.log("OMG I'm using YUI 3.3.0!");
	});
	});

	@example

	Load YUI 3.2.0 and 3.3.0, and instantiate both of them before firing the `ready`
	event. The YUI instances, complete with `use()`ed modules attached, will be made
	available on the `multi` instance.

	var multi = new Y.Multi({
	seeds: {
	Y_320: {
	url: 'http://yui.yahooapis.com/3.2.0/build/yui/yui-min.js',
	use: ['node']
	},

	Y_330: {
	url: 'http://yui.yahooapis.com/3.3.0/build/yui/yui-min.js',
	use: ['node']
	}
	}
	});

	multi.on('ready', function () {
	multi.Y_320.log("OMG I'm using YUI 3.2.0!");
	multi.Y_330.log("OMG I'm using YUI 3.3.0!");
	});

	@module multi
	@class Multi
	@param {Object} config Config object.
	@param {Object} config.seeds Mapping of seed names to either URLs or config
	objects.
	@constructor
	**/

	var doc = Y.config.doc;

	function Multi(config) {
	this._config = Y.merge({
	seeds: {}
	}, config);

	this._iframes = [];
	this._seedCount = Y.Object.size(this._config.seeds);
	this._seedsLoaded = 0;

	/**
	Fired when all requested seed files have been loaded (and instantiated, if
	instantiation was requested). Subscribe to this event in order to be
	notified when you can start using the requested YUI versions.

	@event ready
	@fireOnce
	**/
	this.publish('ready', {fireOnce: true});

	Y.Object.each(this._config.seeds, this._createFrame, this);
	}

	Multi.prototype = {
	_createFrame: function (seed, name) {
	var iframe = doc.createElement('iframe'),
	self = this,
	url = seed.url \|\| seed,
	use = seed.use,
	iframeDoc;

	iframe.style.display = 'none';

	this._iframes.push(iframe);
	doc.body.insertBefore(iframe, doc.body.firstChild);

	// Load the YUI seed URL into the iframe when it loads.
	iframe.onload = function () {
	// If a "use" array was passed, create a YUI instance before
	// indicating completion. Otherwise, just attach the YUI global.
	if (use) {
	self[name] = iframe.contentWindow.YUI().use(use, function () {
	self._seedLoaded();
	});
	} else {
	self[name] = iframe.contentWindow.YUI;
	self._seedLoaded();
	}
	};

	iframeDoc = iframe.contentWindow.document;

	iframeDoc.write(
	'<!DOCTYPE html>' +
	'<html>' +
	'<head>' +
	'<meta charset="utf-8">' +
	'<title>MultiYUI: ' + name + '</title>' +
	'<script src="' + url + '"></script>' +
	'</head>' +
	'<body></body>' +
	'</html>'
	);

	// Allows window.onload to fire.
	iframeDoc.close();
	},

	_seedLoaded: function () {
	this._seedsLoaded += 1;

	if (this._seedsLoaded === this._seedCount) {
	this.fire('ready');
	}
	}
	};

	Y.augment(Multi, Y.EventTarget);

	Y.Multi = Multi;

	}, '@VERSION@', {requires: ['event-custom']});