allex_propertymixinslowlevellib/Settable.js

JavaScript mixins for property handling

module.exports = function (inheritMethods, dummyFunc, isFunction, Gettable) {
  'use strict';

  function Settable(){
  }
  Settable.prototype.destroy = 
  Settable.prototype.__cleanUp = dummyFunc;
  Settable.prototype.set = function(name,val){
    return Settable.set(name, val, this);
  };

  ///signature kind of optimized for array forEach and similar methods (for easy bind ...)
  Settable.set = function (name, val, obj) {
    var origval = Gettable.get(obj,name),methodname = 'get_'+name;
    if(origval===val){return false;}

    methodname = 'set_'+name;
    var changed = false;
    if(isFunction(obj[methodname])){
      changed = obj[methodname].call(obj,val);
      if (changed && isFunction(changed.done)) return changed;
      return changed!==false;
    }

    if (!(name in obj)) {
      //console.warn ('Settable problem: "'+name+'" cannot be set on', obj, 'with value', val);
      throw new Error('"'+name+'" cannot be set');
    }
    obj[name] = val;
    return true;

  };

  Settable.addMethods = function (chld) {
    inheritMethods(chld, Settable, 'set');
  };
  return Settable;
};