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

<blockquote>
  <p>Uncaught TypeError: Cannot read property 'roll' of undefined(...)</p>
</blockquote>

<p>I have tried:</p>

<ul>
<li><code>app.methods.roll(6);</code></li>
<li><code>app.methods.roll.roll(6);</code></li>
<li><code>roll.roll()</code></li>
<li><code>roll()</code></li>
</ul>

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

<pre><code>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.
  }
}
</code></pre>