The problem with the function scope object

There is an object created via new:

function class_1()
{
this.A_1;
this.B_1;
}

class_1.prototype.func_class_1 = function()
{
	/*
		here are some actions with variables this.A_1, this.B_1
	*/
}

function class_2 (_obj /*object of type class_1*/)
{
this.A_2;
this.B_2;
this.Obj_2 = _obj;
}

class_2.prototype.func_class_2  = function()
{
	//function call problem !!!
	this.Obj_2.func_class_1();
}

var o1 = new class_1();
var o2 = new class_2(o1);

o2.func_class_2(); //Uncaught Error: Field or method "func_class_1()" does not already exist, and can't create it on undefined

Help !
I tried various options with this, call and bind, nothing helped. How to organize a call to "this.Obj_2.func_Class_1()" ?

Which firmware version are you running this on, and on what device?

I just ran this on the latest builds and it works fine.

However: If you put this in the right-hand side of the web IDE you get loads of errors. I'd fix those first.

Specifically what do you intend to do with this.A_1;/etc? You're just referencing fields that don't exist yet, without setting them to anything.

Thank you for such a quick response !
I use the cost of production of Amperka (http://amperka.ru/) - "IskraJS" based on Espruino 1v92.194

In the code there are no syntax errors it builds and runs fine, below part of code:

function TObj_1(_pin)
{	
	/*** константы класса ***/
	this.MinPulse = 453.0; //минимальная длительность импульса которая соответствует крайнему "меньшему" положения ротора
	this.MaxPulse = 2050.0; //макисмальная длительность импульса которая соответствует крайнему "меньшему" положения ротора
	this.Ks = 8.7; //коэффициент преобразования в ф-ции Y=kA+B (линейная кривая самого сервопривода
		
	/*** поля класса ***/
	this.Pin = null; //пин микропроцессора на котором "сидит" сервопривод
	this.Value = 0.0; //конечное значение яркости свечения
	this.CurValue = 0.0; //текущее значение яркости свечения
	this.Speed = 0.0; //текущая скорость процесса

	this.Pin = _pin; //задать пин к которому привязан сервопривод
}
TObj_1.prototype.BunRunAnimation = function()
{
	this.FlagBunAnimation = true; //запретить "ручной" запуск Animation(...)
		this.StopAnimation(); //остановить текущую анимацию
};

function TObj_2(_tobj_1)
{
	this.PHASE_ARR = [ "START_MOVE", "START_WAIT", "DOWN_MOVE", "DOWN_WAIT", "UP_MOVE", "UP_WAIT" ];
	
	this.ANGLE_START = 30; //конечный угол ротора фазы START_MOVE
	this.ANGLE_UP = 20; //конечный угол ротора фазы UP_MOVE
	this.ANGLE_DOWN = 0; //конечный угол ротора фазы DOWN_MOVE
	
	this.TIME_START = 15; //время нахождения в позиции START_WAIT, секунд
	this.TIME_UP = 0.5;  //время нахождения в позиции UP_MOVE, секунд
	this.TIME_DOWN = 0.7;  //время нахождения в позиции UP_WAIT, секунд
		
	this.SPEED_START = 25; //скорось движения ротора в фазе START_MOVE, %/s
	this.SPEED_UP = 40;  //скорось движения ротора в фазе UP_MOVE, %/s
	this.SPEED_DOWN = 25;  //скорось движения ротора в фазе DOWN_MOVE, %/s
	
	this.INTERVAL_PLAY = 60.0; //определяет период в ms запуска внутренней ф-и setTimeout
	

	this.Obj1 = _tobj_1; //инициируем поле объектом класса Servo
};
TObj_2.prototype.TaskRun = function()
{
	let _this = this;
	
	if( !_this.FlagTaskRun )
		{
			_this.FlagTaskRun = true; 
				_this.Obj1.BunRunAnimation(); //Error !
			
			_this.CurPhase = _this.PHASE_ARR[0]; 
		}
		
	switch(_this.CurPhase)
	{
		case "START_MOVE":
							if( !_this.FlagSTART_MOVE )
							{
								_this.Obj1.AnimationTask(_this.ANGLE_START, _this.SPEED_START);
									_this.FlagSTART_MOVE = true;
							}
							else
							{
								if ( !_this.Obj1.GetStatusRunAnimation() ) //Error !
								{
									_this.CurPhase = _this.PHASE_ARR[1]; 
										_this.FlagSTART_MOVE = false; 
								}
							}
							
			break;
};

Moving this to 'other boards' - IskraJS isn't an official board - they're just using the Open Source Espruino firmware.

I've tried to run your code even on a 1v92 version of Espruino and it works (without the Exception) - perhaps you could contact Amperka to see if they can help you out.

Thanks again !
Already sent a request to Amperka

The problem is solved. Loss of context occurred in one of the plugins. The firmware of the Amperka code executes correctly.

Great! By 'loss of context', you mean you called it in a setTimeout or something?

Yes, "this" was lost in one of setTimeout

JavaScript provides you with standard means to ensure the desired context:

• You can pass parameter for the function in

  setTimeout(function(_, otherParms,...){
  _.memberOfContextObject;
  _.memberOfContextObject();
  }, timeoutTimeInMS, contextObject, otherParms,...);
  

• Alternative is to bind the function and then pass to `

  setTimeout(function(otherParms,...){
  this.memberOfContextObject;
  this.memberOfContextObject();
  }.bind(contextObject), timeoutTimeInMS, otherParms,...);
  

• This works too, but is not as flexible as above options:

  function anyFunctionOfThis() {
  var _this = this; // create non-this reference of this
  setTimeout(function(otherParms,...){
    _this.memberOfContextObject;
    _this.memberOfContextObject();
  }, timeoutTimeInMS, otherParms,...);
  

As you know, you can defined the function as a named function outside of setTimeout(... or setInterval(... or ..., functionAsCallbackParm,...either as function or 'method of an object' (see object-oriented programming with JS). I use this when I have to provide them as callbacks in multiple places:

var fun      = function(otherParms,...) { ... };
var funBound = fun.bind(contextObject);

setTimeout(funBound, timoutTimeInMS, otherParms,...

There are many options and combinations there of you can chose from for the optimal use in your situation.

For the alternative 'this', I use the _this or short form of it _ to indicate that it is about the this / context object. I've also seen that to be used. But I prefer a more eye catching - and short - form, therefore: _ is my choice.

Or.. if the contextObject you need is the outer scope just use a arrow function as setTimeout callback and be done with it.

Other public choices for the this alter ego are me and self :D

Thank you all for the advice !

function myclassA()
{
	this.A = 1;
	this.TimerID = null;
}

myclassA.prototype.func_1 = function()
{
	/* here some code */
	this.TimerID = setInterval(this.func_2.bind(this), 50);
}

myclassA.prototype.func_2 = function()
{
	/* There was an error ! )) */
}

function myclassB(_object)
{
	this.B = 1;
	this.Obj = _object;
}

myclassB.prototype.func_1 = function()
{
	/* here some code */
	this.Obj.func_1();
}

...?

...do not exactly get what above code should proof or disproof...

(function(){
var MyClassA = function(name, checkInInterval)
  {
    this.name = name;
    this.checkInInterval = checkInInterval;
    this.TimerID = null;
    this.commander = null;
  }
MyClassA.prototype.func_1 = function(commander)
  {
    /* here some code */
    this.commander = commander;
    this.TimerID = setInterval(this.func_2.bind(this), this.checkInInterval);
  }
MyClassA.prototype.func_2 = function()
  {
    var time = (typeof getTime != "undefined") ? getTime() : new Date().getTime();
    console.log(Math.floor(time)
       + ": Hi, my name is " + this.name
       + "; " + this.commander.name
       + " commanded me to check in"
       + " every " + (this.checkInInterval / 1000)
       + " seconds. --- Bye!");
  }

var MyClassB = function(name, _object)
  {
    this.name = name;
    this.Obj = _object;
  }
MyClassB.prototype.func_1 = function()
  {
    /* here some code */
    this.Obj.func_1(this);
  }

var objAlf, objAnn, objBen, objBob;

var onInit = function()
  {
    objAlf = new MyClassA("Alf",2000);
    objAnn = new MyClassA("Ann",5000);
    objBen = new MyClassB("Ben",objAlf);
    objBob = new MyClassB("Bob",objAnn);
    objBen.func_1();
    objBob.func_1();
  }
  
setTimeout(onInit, 1000);
})()

Should run in Espruino and provide output in the console like that:

1513144683321: Hi, my name is Alf; Ben commanded me to check in every 2 seconds. --- Bye!
1513144685319: Hi, my name is Alf; Ben commanded me to check in every 2 seconds. --- Bye!
1513144686318: Hi, my name is Ann; Bob commanded me to check in every 5 seconds. --- Bye!
1513144687321: Hi, my name is Alf; Ben commanded me to check in every 2 seconds. --- Bye!
1513144689322: Hi, my name is Alf; Ben commanded me to check in every 2 seconds. --- Bye!
1513144691320: Hi, my name is Alf; Ben commanded me to check in every 2 seconds. --- Bye!
1513144691321: Hi, my name is Ann; Bob commanded me to check in every 5 seconds. --- Bye!
1513144693321: Hi, my name is Alf; Ben commanded me to check in every 2 seconds. --- Bye!
1513144695319: Hi, my name is Alf; Ben commanded me to check in every 2 seconds. --- Bye!
1513144696318: Hi, my name is Ann; Bob commanded me to check in every 5 seconds. --- Bye!

...you can also just open the debugger of (chrome) browser (with 'right-click' Inspect) and paste the code into the console... :)

As the output shows, Alf - objAlf - and Ann - objAnn- know still about their names, their time interval to show up, and who commanded them: Ben and Bob.