title: Vue class binding on this input field
body: <p>I would like to bind a class on the input field where this class is suppose to be applied. In my case I have input fields that I am dynamically creating and since I can't bind values with v-model for input fields that are dynamically created I can't bind the class with <code>v-model</code> data.
  This are the fields that I am creating inside of <code>v-for</code> loop:</p>
  
  <pre><code>  &lt;template v-for="input in ninjaForm.fields"&gt;
      &lt;div class="control"&gt;
        &lt;input
          class="input is-large"
          :class="{ hasValue: input.value }"
          :ref="input.label.toLowerCase()"
          :type="input.type"
          :name="input.label.toLowerCase()"
          :required="input.required == 1"&gt;
        &lt;label&gt;{{ input.label }}&lt;/label&gt;
      &lt;/div&gt;
    &lt;/template&gt;
  </code></pre>
  
  <p>I would like to know how can I bind a class now with that input field, so that I can check if the input field has some kind of value, so for example something like this:</p>
  
  <pre><code>:class="{ 'has-value' : this.input.value != ''}"
  </code></pre>
  
  <p>Hoe can I do that with Vue?</p>