title: Vue.js - Element UI - Dynamic rules validation form
body: <p>I'm using <code>vue-js2.3</code> and <code>element-ui</code>.</p>
  
  <p>I would like to define the validation rules of my form dynamically</p>
  
  <h3>Example</h3>
  
  <p><a href="https://jsfiddle.net/cgL6y9kq/" rel="noreferrer">https://jsfiddle.net/cgL6y9kq/</a></p>
  
  <h3>Problem</h3>
  
  <p>The <code>required</code> is not dynamically defined by <code>phoneMandatory</code></p>
  
  <h3>Questions</h3>
  
  <p>How can I change the attribute on an existing rule dynamically?
  How can I add or remove rules dynamically ?</p>