using-a-computed-property.html

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<!--
# Using a Computed Property

Shows data binding to a property that is computed based on other property
values.

Define computed properties in the `computed` object on the element’s prototype:

    Polymer({
      firstName: 'Rob',
      lastName: 'Dodson',
      computed: {
        fullName: "firstName + ' ' + lastName"
      }
    });

A computed property consists of a property name and a Polymer expression.
When any value in the expression changes, the computed property updates.

In this example, `fullName` is a computed property that updates whenever
`firstName` or `lastName` change.

Read the
[official documentation for computed properties](http://www.polymer-project.org/docs/polymer/polymer.html#computed-properties).

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

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

<polymer-element name="my-element">
  <template>
    <label>First Name: <input type="text" value="{{firstName}}"></label>
    <label>Last Name: <input type="text" value="{{lastName}}"></label>
    <div>Full name: {{fullName}}</div>
  </template>
  <script>
    Polymer({
      firstName: 'Rob',
      lastName: 'Dodson',
      computed: {
        fullName: "firstName + ' ' + lastName"
      }
    });
   </script>
</polymer-element>