code: function() {
      var c=[], ce=this.childElements, celts=this.ctlElements, eltType;
      if (ce && ce.length) {
        for (var i=0, sz=ce.length;sz>i;i++) {
          eltType=celts[ce[i].name].type;
          if (eltType==="component") {
            c.push(ce[i].controller);
          } else if (eltType==="template") {
            c.push(ce[i]);
          } else {
            log.error(this+" Invalid element type: "+eltType);
          }
        }
      }
      return c.length>0? c : null;
    }
docs: Calculate the content array that will be set on component's controller