Simple Javascript Templating


Suppose you need just a little bit of templating functionality, here’s a code snippet for you:

 * Very simple find/replace template.
 * Optional filter function that is used on tags with three curlies. Ex: `}`
 * @function {mixin} Application.template
 * @param {string} t templateable string
 * @param {object} d data object
 * @... {string} yourKey containing value to replace
 * @param {function(value)} filter a filter function that is passed members of `d` that are templated by triple curlys
 * @return {string} string with templates filled
 * @author [Jasper Palfree](
 * @license [GPLv3](
 * @example
 * This will return the text: `this is a template!`

 * 	template("this is a ", {what: "template!"});
 * @example
 * This will return the text: `this is a template!`

 * 	template("this is a ", {nested: {what:'template!'} });
function template(t, d, filter){
	var data = d;
	var ret = t;
	var segments = ret.match(/\\{?\\{\\{[a-zA-Z$_][a-zA-Z0-9_.$]*\\}\\}\\}?/g);
	for(var x=0, len = segments.length; x < len; x++){
                    var tags = segments[x].replace(/[\\{\\}]*/g,').split('.');
		var id = tags.shift();
                    var repl = (tags.length > 0)? arguments.callee('+tags.join(',data[id],filter) : '+data[id];
		if(segments[x].match(/^\\{\\{\\{/) && typeof filter === 'function'){
			repl = filter(repl);
		ret = ret.replace(segments[x], repl);
	return ret;

What can you do with it?

Well, let’s say you have some data in javascript that you want to put into the DOM.

// mimicking retrieval from data source
var entries = [
    {id:'1', data: {title:"Title1", content:"<p>This is an entry</p>"}},
    {id:'2', data: {title:"Title2", content:"<p>This is another entry</p>"}},
    {id:'3', data: {title:"Title3", content:"<p>This is yet another fracking entry</p>"}}

What you can do is set up a template in your HTML, by placing it in script tags and specify a type such as type="text/html". For example, you may do something like this:

<script type="text/html" id="tpl-entry">
    <div class="entry">
        <div class="content">

Now you can retrieve the inner html of that script tag and use it as the template for your data, like so:

var el = document.getElementById('entryWrap'),
    tpl = document.getElementById('tpl-entry').innerHTML,
    html = ';
for(var x in entries){
    html += template(tpl, entries[x]);

If you like, you can also add a filter function that can filter any data in the template called with a triple-curly.

Here’s the full example usage on jsFiddle.