title: Can't get prop to update in vue.js component
body: <p>I have been trying for hours to get this to work. I need to update a boolean that is passed to a child component, but it always returns <code>false</code>.</p>
  <p>I have created the variable with a default value <code>false</code> here.</p>
  <p><code>someApp.js</code></p>
  <pre><code>let someApp = new Vue({
      el: &quot;#app&quot;,
      data: {
          // ... irrelevent data
          showDialogRepair: false
      },
  </code></pre>
  <p>I also have the following method defined in <code>someApp.js</code>:</p>
  <pre><code>add_repair: function () {
             this.showDialogRepair = true
              console.log(this.showDialogRepair)
          },
  </code></pre>
  <p>I'm using another component <code>some-list</code> inside of <code>someApp</code> and passing my <code>showDialogRepair</code> variable as a prop called <code>showData</code>:</p>
  <pre><code>&lt;some-list
    ...
    :showData=&quot;showDialogRepair&quot;
    ...
  &gt;
  &lt;/some-list&gt;
  </code></pre>
  <p>The variable <code>showDialogRepair</code> is updated by the <code>add_repair()</code> function and <code>console.log</code> returns <code>true</code></p>
  <p>Now inside <code>repair-list</code> I have registered my props:</p>
  <pre><code>Vue.component('some-list', {
      props: {
          ...
          showData: {type: Boolean}
      },
  </code></pre>
  <p>My data:</p>
  <pre><code>data: function () {
          return {
              ...
              showDialogRepair: this.showData
          }
      },
  </code></pre>
  <p>and finally the method I am calling from the child component <code>some-list</code>:</p>
  <pre><code>add_new_repair: function () {
              console.log(this.showData)
          },
  </code></pre>
  <p>Which is returning <code>false</code></p>
  <p>I have also tried to add a watcher in <code>watch:</code></p>
  <pre><code>showDialogRepair: function (newVal, oldVal) {
              this.showDialogRepair = newVal;
          },
  </code></pre>
  <p>Any help is greatly appreciated.</p>