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js/DOMLoader.script.js

@@ -0,0 +1,131 @@
+/*
+
+	DOMLoader : 0.2 : mudcu.be
+	---------------------------
+	DOMLoader.script.add({
+		strictOrder: true,
+		srcs: [
+			{
+				src: "../js/jszip/jszip.js",
+				verify: "JSZip",
+				callback: function() {
+					console.log(1)
+				}
+			},
+			{ 
+				src: "../inc/downloadify/js/swfobject.js",
+				verify: "swfobject",
+				callback: function() {
+					console.log(2)
+				}
+			}
+		],
+		callback: function() {
+			console.log(3)
+		}
+	});
+	
+*/
+
+if (typeof(DOMLoader) === "undefined") DOMLoader = {};
+
+DOMLoader.script = function() {
+	this.loaded = {};
+	this.loading = {};
+	return this;
+};
+
+DOMLoader.script.prototype.add = function(config) {
+	var that = this;
+	var srcs = config.srcs;
+	if (typeof(srcs) === "undefined") {
+		srcs = [{ 
+			src: config.src, 
+			verify: config.verify
+		}];
+	}
+	/// adding the elements to the head
+	var doc = document.getElementsByTagName("head")[0];
+	/// 
+	var testElement = function(element, test) {
+		if (that.loaded[element.src]) return;
+		if (test && !eval(test)) return;
+		that.loaded[element.src] = true;
+		//
+		if (that.loading[element.src]) that.loading[element.src]();
+		delete that.loading[element.src];
+		//
+		if (element.callback) element.callback();
+		if (typeof(getNext) !== "undefined") getNext();
+	};
+	///
+	var batchTest = [];
+	var addElement = function(element) {
+		if (/([\w\d.\[\]])$/.test(element.verify)) { // check whether its a variable reference
+			element.test = "(typeof(" + element.verify + ") !== \"undefined\")";
+			batchTest.push(element.test);
+		}
+		var script = document.createElement("script");
+		script.onreadystatechange = function() {
+			if (this.readyState !== "loaded" && this.readyState !== "complete") return;
+			testElement(element);
+		};
+		script.onload = function() {
+			testElement(element);
+		};
+		script.setAttribute("type", "text/javascript");
+		script.setAttribute("src", element.src);
+		doc.appendChild(script);
+		that.loading[element.src] = function() {};
+	};
+	/// checking to see whether everything loaded properly
+	var onLoad = function(element) {
+		if (element) {
+			testElement(element, element.test);
+		} else {
+			for (var n = 0; n < srcs.length; n ++) {
+				testElement(srcs[n], srcs[n].test);
+			}
+		}
+		if (!config.strictOrder && eval(batchTest.join(" && "))) { // finished loading all the requested scripts
+			if (config.callback) config.callback();
+		} else { // keep calling back the function
+			setTimeout(function() { //- should get slower over time?
+				onLoad(element);
+			}, 10);
+		}
+	};
+	/// loading methods;  strict ordering or loose ordering
+	if (config.strictOrder) {
+		var ID = -1;
+		var getNext = function() {
+			ID ++;
+			if (!srcs[ID]) { // all elements are loaded
+				if (config.callback) config.callback();
+			} else { // loading new script
+				var element = srcs[ID];
+				var src = element.src;
+				if (that.loading[src]) { // already loading from another call (attach to event)
+					that.loading[src] = function() {
+						if (element.callback) element.callback();
+						getNext();
+					}
+				} else if (!that.loaded[src]) { // create script element
+					addElement(element);
+					onLoad(element);
+				} else { // it's already been successfully loaded
+					getNext();
+				}
+			}
+		};
+		getNext();
+	} else { // loose ordering
+		for (var ID = 0; ID < srcs.length; ID ++) {
+			if (that.loaded[srcs[ID].src]) return;
+			addElement(srcs[ID]);
+		}
+		onLoad();
+	}
+};
+
+DOMLoader.script = (new DOMLoader.script());