programmatically-changing-the-styles-of-an-element.html

<!--
Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
Code distributed by Google as part of the polymer project is also
subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
-->

<!--
# Programmatically changing the styles of an element

Shows how to change an element's styles by modifying its `style` property.

[jsbin](http://jsbin.com/bator/edit)
-->

<link rel="import" href="../../components/polymer/polymer.html">

<polymer-element name="my-element">
  <template>
    <style>
      :host {
        color: #666;
      }
    </style>
    <p>Inside my-element</p>
    <button on-tap="{{changeColor}}">Change color</button>
  </template>
  <script>
    Polymer({
      created: function() {
        this.colors = ['red', 'green', 'blue'];
      },
      index: 0,
      changeColor: function(e, detail, sender) {
        // Cycle through this.colors.
        this.style.color = this.colors[this.index++ % this.colors.length];
      }
    });
  </script>
</polymer-element>