A simple string template.

string-template.js

/**
 * A simple string template function.
 *
 * For example:
 * 
 * var str = 'Hi, {{ username }}! Your age is {{ age }}. You locate in {{ location.city }}, {{ location.province }}.';
 * var user = {
 *   username: 'Alex Chao',
 *   age: 25,
 *   location: {
 *     province: 'Guangdong',
 *     city: 'Dongguan'
 *   }
 * };
 * stringTmpl(str, user);
 */
function stringTmpl(str, data) {
  var re = /\{\{([\w\W]+?)\}\}/g;
  return str.replace(re, function(m, s1) {
    var val = data;
    s1 = trim(s1).split('.');
    for (var i = 0; i < s1.length; i++) {
      val = val[s1[i]];
    }
    return val;
  });
}

function trim(str) {
  return str.trim ? str.trim() : str.replace(/^\s+/, '').replace(/\s+$/, '');
}