Nano Templater

gistfile1.js

var getTemplate = (function (html) {
	var templates = {};
	//<([A-Z]\w+)[^>]*>([\s\S]*?)<\/([A-Z]\w+)[^>]*>
	html.replace(/<template\s+data-template-name="(.+)"\s*>([\s\S]*?)<\/template>/g, function (str, name, value) {
		templates[name] = value.replace(/([>{])\s+|\s+([<}])/g, '$1$2').replace(/\s+/g, ' ');
	});
	return function (name, data) {
		var template = templates[name];
		if (data) {
    	template = template.replace(/{{([^{}]+)}}/gm, function (match, p1) {
				return data[p1];
			});
		}
		return template;
	}
}(html));

https://jsfiddle.net/e6makt9p/16/