title: Vue warn invalid value from option expected an object but got function
body: <p>I'm trying to bind a computed function to my style. And in this computed function I'm using a property. But Vue gives me the error that it expects an object but gets a function. This is my code.</p>
  
  <pre><code>&lt;template&gt;
    &lt;div id="banner" :style="extractImageURL"&gt;
  
    &lt;/div&gt;
  &lt;/template&gt;
  
  &lt;script&gt;
  export default {
      props: ['imageURL'],
      computed(){
        extractImageURL()
        {
          return "background-image: url(" + this.imageURL + ");"
        }
      }
  }
  &lt;/script&gt;
  </code></pre>