This is not a Drill

Sooo… This is it. DoD. TH does that mean.. who knows, but it sounds cool.

While working on an Ionic project today (A game sorta app), Firebase errors started to kick in. After a couple minutes of debugging, found out i could’nt use “this” in an anonymous javascript function. here’s the snippet.


 GameStatus.on('value', function(snapshot) {
    console.log(snapshot.val())
    this.deck = snapshot.val().deck
    this.card = snapshot.val().initCard
    this.playerTwoCards = snapshot.val().joinCard
    this.lastCard = snapshot.val().lastcard
    this.isTurn = snapshot.val().status

    console.log(this.playerTwoCards);      
    console.log("Cards Updated")
    console.log('Local deck is '+deck)
    console.log('Global deck is '+this.deck)
      
    console.log(snapshot.val())
     });

The error was simple and confusing this is null. After a couple of minutes of googling, I found out that it had something to do with Javascript Closures. So yeah, “this” was null. Then I Tried something funny. I don’t know why I thought it would work.

    GameStatus.on('value', function(snapshot) {
        console.log(snapshot.val())
       JoinedGame.prototype.deck = snapshot.val().deck
       JoinedGame.prototype.card = snapshot.val().initCard
       JoinedGame.prototype.playerTwoCards = snapshot.val().joinCard
       JoinedGame.prototype.lastCard = snapshot.val().lastcard
       JoinedGame.prototype.isTurn = snapshot.val().status

        console.log(JoinedGame.prototype.playerTwoCards);
        console.log("Cards Updated")
        console.log('Local deck is '+deck)
        console.log('Global deck is '+this.deck)
      
       console.log(snapshot.val())
     });

Of course, that would’nt work …What the heck does prototype do?

Eventually, I came up with this solution. The Correct solution by the way.

    var _this = this;
    GameStatus.on('value', function(snapshot) {

      _this.deck = snapshot.val().deck
      _this.card = snapshot.val().joinCard
      _this.playerTwoCards = snapshot.val().initCard  
      _this.lastCard = snapshot.val().lastcard
      _this.isTurn = snapshot.val().status
      console.log("Cards Updated")
      console.log(snapshot.val())
      console.log(deck); //not null

    });

And the rest sorted Itself out. Off to more debugging now… I’ll be updating this as more stuff happens.

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