4 * Use `Polymer.PaperInputAddonBehavior` to implement an add-on for `<paper-input-container>`. A
5 * add-on appears below the input, and may display information based on the input value and
6 * validity such as a character counter or an error message.
9 Polymer.PaperInputAddonBehavior = {
15 attached: function() {
16 this.fire('addon-attached');
20 * The function called by `<paper-input-container>` when the input value or validity changes.
22 * inputElement: (Node|undefined),
23 * value: (string|undefined),
24 * invalid: (boolean|undefined)
25 * }} state All properties are optional -
26 * inputElement: The input element.
27 * value: The input value.
28 * invalid: True if the input value is invalid.
30 update: function(state) {