onChange


<h1>onChange</h1>
<h2>(const)</h2>
<div>
<p>Notify a directive when any of its bindings have changed.</p>
<p>This method is called right after the directive&#39;s bindings have been checked,
and before any of its children&#39;s bindings have been checked.</p>
<p>It is invoked only if at least one of the directive&#39;s bindings has changed.</p>
.l-main-section
  h2 Example:
pre(class="prettyprint linenums")
  code.
@Directive({
  selector: '[class-set]',
  properties: [
    'propA',
    'propB'
  ],
  lifecycle: [onChange]
})
class ClassSet {
  propA;
  propB;
  onChange(changes:{[idx: string, PropertyUpdate]}) {
    // This will get called after any of the properties have been updated.
    if (changes['propA']) {
      // if propA was updated
    }
    if (changes['propA']) {
      // if propB was updated
    }
  }
}
</div>