microtemplates.js

/**
 * from Secrets of the JavaScript Ninja by John Resig 
 * Example:
 * 
 * var hello = tmpl("Hello, <%= name %>!");
 * alert(hello({name: "world"}));
 */
(function() {
	var cache = {};
	this.tmpl = function tmpl(str, data) {
		// Figure out if we're getting a template, or if we need to
		// load the template - and be sure to cache the result.
		var fn = !(/\W/.test(str)) ? cache[str] = cache[str] || tmpl(document.getElementById(str).innerHTML) :
    		// Generate a reusable function that will serve as a template
    		// generator (and which will be cached).
    		new Function("obj", "var p=[],print=function(){p.push.apply(p,arguments);};" +
    		// Introduce the data as local variables using with(){}
    		"with(obj){p.push('" +
    		// Convert the template into pure JavaScript
    		str
    		    .replace(/[\r\t\n]/g, " ")
    		    .split("<%").join("\t")
    		    .replace(/((^|%>)[^\t]*)'/g, "$1\r")
    		    .replace(/\t=(.*?)%>/g, "',$1,'")
    		    .split("\t").join("');")
    		    .split("%>").join("p.push('")
    		    .split("\r").join("\\'")
    		+ "');}return p.join('');");

		// Provide some basic currying to the user
		return data ? fn(data) : fn;
	};
})();