URL Tag replace

url_tag_replace.js

/* User data sample */
var user = {
  uid: 5678,
  email: '[email protected]'
};
/* Tag separator: *| */
/* g modiffier is mandatory */
var pattern = /\*\|([a-zA-Z0-9_]+)\|\*/g; 
var url = 'http://www.acme.com/tnt/buy/?user=*|UID|*&email=*|EMAIL|*&size=*|SIZE|*';

var result;
var results = [];
/*Iterate all results*/
while((result = pattern.exec(url)) !== null){
  if(result.index === pattern.lastIndex){
    pattern.lastIndex++;
  }
  //Save all match and group match
  results.push({
    tag: result[0],
    variable: result[1]
  });
}

for(var i = 0; i < results.length; i++){
  var tag = results[i].tag;
  var variable = results[i].variable;
  //Find tag within URL and replace it by variable value
  if(user[variable.toLowerCase()]){
    url = url.replace(tag, user[variable.toLowerCase()]);
  }
  
}

console.log(url);