CanJS Live Value Control

gistfile1.js

var stringify = function(obj) {
    if(obj === undefined || obj === null) {
    } else if(typeof obj === "object") {
      if(obj instanceof can.Observe) { // Get native object or array from Observe or Observe.List
        obj = obj.attr()
      } else { // Clone object to prevent change original values
        obj = can.isFunction(obj.slice) ? obj.slice() : can.extend({}, obj)
      }
      // Convert each object property or array item into stringified new
      can.each(obj, function(val, prop) { obj[prop] = stringify(val) })
    } else if(can.isFunction(obj.toString)) {
      obj = obj.toString()
    }

    return obj
  }

return can.Control('LiveValue', {
  init: function(el) {
    var opt = this.options

    // Todo refactor
    if(opt.obj && opt.prop) {
      // Fine
    } else if(opt.obj && !opt.prop) {
      var elName = el.attr('name')

      if(elName) {
        opt.prop = el.attr('name')

        this.on()
      } else {
        console.warn("Cant initialize LiveValue control without option 'prop' or element name attribute")

        this.destroy()
        return
      }
    } else if(!opt.compute) {
      console.warn("Cant initialize LiveValue control without 'obj' or 'compute'")

      this.destroy()
      return
    }

    this.set()
  },
  "{obj} {prop}": "set",
  "{compute} change": "set",
  set: function() {
    var opt = this.options,
        el = this.element,
        val;

    if(this.hasObj()) {
      val = opt.obj.attr(opt.prop);
    } else if(this.hasCompute()) {
      val = opt.compute()
    }

    el.val(stringify(val))
  },
  "change": function() {
    var opt = this.options,
        val = this.element.val();

    if(this.hasObj()) {
      opt.obj.attr(opt.prop, val)
    } else if(this.hasCompute()) {
      opt.compute(val)
    }
  },
  "keydown": function(el, ev) {
    if(ev.keyCode == 13) {
      this.element.trigger('change')
    }
  },
  hasObj: function() {
    var opt = this.options;

    return opt.obj && opt.prop;
  },
  hasCompute: function() {
    return this.options.compute;
  }
});