curl-amd/src/curl/plugin/link.js

curl.js is small, fast, extensible module loader that handles AMD, CommonJS Modules/1.1, CSS, HTML/text, and legacy scripts.

/** MIT License (c) copyright 2010-2013 B Cavalier & J Hann */

/**
 * curl link! plugin
 *
 * Licensed under the MIT License at:
 * 		http://www.opensource.org/licenses/mit-license.php
 *
 */

(function (global) {
"use strict";

/*
 * curl link! plugin
 * This plugin will load css files as <link> elements.  It does not wait for
 * css file to finish loading / evaluating before executing dependent modules.
 * This plugin also does not handle IE's 31-stylesheet limit.
 * If you need any of the above behavior, use curl's css! plugin instead.
 *
 * All this plugin does is insert <link> elements in a non-blocking manner.
 *
 * usage:
 * 		// load myproj/comp.css and myproj/css2.css
 *      require(['link!myproj/comp,myproj/css2']);
 *      // load some/folder/file.css
 *      define(['css!some/folder/file'], {});
 *
 * Tested in:
 *      Firefox 1.5, 2.0, 3.0, 3.5, 3.6, and 4.0b6
 *      Safari 3.0.4, 3.2.1, 5.0
 *      Chrome 7+
 *      Opera 9.52, 10.63, and Opera 11.00
 *      IE 6, 7, and 8
 *      Netscape 7.2 (WTF? SRSLY!)
 * Does not work in Safari 2.x :(
*/


	var
		// compressibility shortcuts
		createElement = 'createElement',
		// doc will be undefined during a build
		doc = global.document,
		// regexp to find url protocol for IE7/8 fix (see fixProtocol)
		isProtocolRelativeRx = /^\/\//,
		// find the head element and set it to it's standard property if nec.
		head;

	if (doc) {
		head = doc.head || (doc.head = doc.getElementsByTagName('head')[0]);
	}

	function nameWithExt (name, defaultExt) {
		return name.lastIndexOf('.') <= name.lastIndexOf('/') ?
			name + '.' + defaultExt : name;
	}

	function createLink (doc, href) {
		var link = doc[createElement]('link');
		link.rel = "stylesheet";
		link.type = "text/css";
		link.href = href;
		return link;
	}

	function fixProtocol (url, protocol) {
		// IE 7 & 8 can't handle protocol-relative urls:
		// http://www.stevesouders.com/blog/2010/02/10/5a-missing-schema-double-download/
		return url.replace(isProtocolRelativeRx, protocol + '//');
	}

	define(/*=='curl/plugin/link',==*/ {

//		'normalize': function (resourceId, toAbsId) {
//			// remove options
//			return resourceId ? toAbsId(resourceId.split("!")[0]) : resourceId;
//		},

		'load': function (resourceId, require, callback, config) {
			var url, link, fix;

			url = nameWithExt(require['toUrl'](resourceId), 'css');
			fix = 'fixSchemalessUrls' in config ? config['fixSchemalessUrls'] : doc.location.protocol;
			url = fix ? fixProtocol(url, fix) : url;
			link = createLink(doc, url);
			head.appendChild(link);

			callback(link.sheet || link.styleSheet);

		}

	});

})(this);