title: How to disable button when input is empty in Vue?
body: <p>I'd bind a button to input using v-bind with a function :</p>
  <p>The code inside my <strong>template</strong> :</p>
  <pre><code>&lt;template&gt;
    &lt;input
      type=&quot;email&quot;
      v-model=&quot;email&quot;
      v-bind:placeholder=&quot;$t('fields.email_place_holder')&quot;
    /&gt;
    &lt;input
      v-bind:disabled=&quot;{ isDisable }&quot;
      type=&quot;submit&quot;
      v-bind:value=&quot;$t('buttons.notify_me')&quot;
      class=&quot;notify-me-button&quot;
    /&gt;
  &lt;/template&gt;
  </code></pre>
  <p>The code inside my <strong>script</strong> :</p>
  <pre><code>  methods: {
      isDisable() {
        return email.lenght &gt; 0;
      }
    }
  </code></pre>
  <p>But the <code>button</code> does not change its status , I tried to change the <strong>css style</strong> with the same way and the result is the same.The problem is that button responds once time on the first value returned by <code>isDisable()</code>.</p>