gistfile1.txt

$(".content").weld({
  some : "data",
  user  : "tmpvar"
}, function(el, key, value) {
  if (key === "user") {
    el.attr(src, '/path/to/' + value);
  }
});


$(".content").weld({
  some : "data",
  user  : "tmpvar"
},
{
  insert : function(parent, element, cb) {
    // append or prepend or etc
    if(cb) {
      parent.append(cb(element));
    }    
    else {
      parent.append(element);
    }
  }
})