[Javascript] Undefined

[Chaosy]

When I launch my code I get the "ERROR: Cannot read property 'getFullYear' of undefined"

I've managed to track it down:

if (!isNaN(Date.parse(finishedD)) && finishedD !== undefined){ //I even filter out undefined here, but that did not help as you see.
  _finishedDate = finishedD;
  console.log(this.dueDate + '   ' + finishedD);
  console.log(this.dueDate + '   ' + _finishedDate);
  _isDone = true;
  console.log('pre crash');
  if (!this.inTimeFilter()) {
    _isOverdue = true;
  }
  console.log('aftermath');
}

Which writes out:
Thu Dec 31 2015 00:00:00 GMT+0100 (Västeuropa, normaltid) Wed Mar 02 2016 00:00:00 GMT+0100 (Västeuropa, normaltid)
Thu Dec 31 2015 00:00:00 GMT+0100 (Västeuropa, normaltid) Wed Mar 02 2016 00:00:00 GMT+0100 (Västeuropa, normaltid)
pre crash

So the issue is the !this.inTimerFilter()

inTimeFilter() {
  console.log(this.dueDate + '   ' + this.finishedDate);
  return this.finishedDate.getFullYear() <= this.dueDate.getFullYear() &&
    this.finishedDate.getMonth() <= this.dueDate.getMonth() &&
    this.finishedDate.getDate() <= this.dueDate.getDate();
}

Which writes:
Thu Dec 31 2015 00:00:00 GMT+0100 (Västeuropa, normaltid) undefined

What. It was fine just before calling the method.

 

[Dr Super Good]

The problem is that dueDate does not have a member function named getFullYear.
Please post the full script.

 

[Chaosy]

It does.
dueDate is of the type Date which have that function.
JavaScript Date Reference

edit: the problem is that this.finishedDate is undefined somehow. Despite it having a value one line above.

 

[Aniki]

Where do you set this.finishedDate?

I think these kind of problems are easiest to track down while stepping through the debugger. I think all major browsers have pretty good javascript debuggers and they are easy to use.

 

[Chaosy]

Okay I debugged further.

I found something useful.
If I make another variable, and make it reference _finishedDate, and then use that one instead of finishedDate, it works.
I have no clue why and it's ugly as fuck.

_finishedDate = value;
this.test = _finishedDate; //I then use this.test instead of finishedDate

 

[GhostWolf]

Your code doesn't show you setting this.finishedDate, which as I am writing I see Aniki asked about.
But in fact, the question need not be asked, you clearly showed you are not setting it with the log message Thu Dec 31 2015 00:00:00 GMT+0100 (Västeuropa, normaltid) undefined.

Just as a small hint for the future, when you want to log multiple objects, preferably don't concatenate them with implicit string conversion.
It's usually a lot more useful to be able to see the actual objects (e.g. in Chrome's devtools).
For example, where you print the dates, I would have done console.log(this.dueDate, this.finishedDate).
This becomes more obvious when you delve into non-native objects (your own classes, etc.), where with string concatenation you will get something along the lines of "[object Object]", which is very unhelpful.

And finally as a side note, both null and undefined evaluate to false, so unless you need to differentiate these cases, you can drop equality tests, e.g. if (object) is the same as if (object !== null && object !== undefined).

 

[Chaosy]

this.finishedDate is a capsuled (is that the right word?) version of _finishedDate to make it private. And since I do set _finishedDate as shown above, this.finished date which refers to _finishedDate, should have the same value, right?

Object.defineProperty(this, 'finishedDate', {
  get: function() {
    return _finishedDate;
  },
  set: function(value) {
    if (!isNaN(Date.parse(value))) {
      _finishedDate = value;
      this.test = _finishedDate;
      _isDone = true;
      if (!this.inTimeFilter()) {
        _isOverdue = true;
      }
    } else {
      console.log('happens?'); //no this, does not happen.
      _finishedDate = undefined;
    }
  }
});

 

[Aniki]

Maybe when you call Object.defineProperty(this, 'finishedDate', { ... }); the this variable does not point to the object for which you later call the inTimeFilter method?

See if the window object has it =)...

 

[GhostWolf]

You are returning a global called _finishedDate, which is undefined, as the log message showed. Use this like the rest of the code.
The only reason this.test works is that it is, indeed, using this.

(if you run in a browser environment, for example, then window._finishedDate = value; this.test = window._finishedDate; is what you executed)