I'm using VueJS to make a simple enough resource management game/interface. At the minute I'm looking to activate the roll function every 12.5 seconds and use the result in another function.
At the moment though I keep getting the following error:

Uncaught TypeError: Cannot read property 'roll' of undefined(...)

I have tried:

• app.methods.roll(6);


• app.methods.roll.roll(6);


• roll.roll()


• roll()

but can't seem to access the function. Anyone any ideas how I might achieve this?

methods: {



  // Push responses to inbox.

  say: function say(responseText) {

    console.log(responseText);

    var pushText = responseText;

    this.inbox.push({ text: pushText });

  },



  // Roll for events

  roll: function roll(upper) {

    var randomNumber = Math.floor(Math.random() * 6 * upper) + 1;

    console.log(randomNumber);

    return randomNumber;

  },



  // Initiates passage of time and rolls counters every 5 time units.

  count: function count() {

    function counting() {

      app.town.date += 1;

      app.gameState.roll += 0.2;



      if (app.gameState.roll === 1) {

        var result = app.methods.roll(6);

        app.gameState.roll === 0;

        return result;

      }

    }



    setInterval(counting, 2500);



    ...



    // Activates the roll at times.

  }

}