[](https://www.npmjs.com/package/@polymer/iron-validator-behavior) [](https://travis-ci.org/PolymerElements/iron-validator-behavior) [](https://webcomponents.org/element/@polymer/iron-validator-behavior) ## IronValidatorBehavior Use `IronValidatorBehavior` to implement a custom input/form validator. Element instances implementing this behavior will be registered for use in elements that implement `IronValidatableBehavior`. See: [Documentation](https://www.webcomponents.org/element/@polymer/iron-validator-behavior), [Demo](https://www.webcomponents.org/element/@polymer/iron-validator-behavior/demo/demo/index.html). ## Usage ### Installation ``` npm install --save @polymer/iron-validator-behavior ``` ### In a Polymer 3 element that is a validator ```js import {PolymerElement, html} from '@polymer/polymer'; import {mixinBehaviors} from '@polymer/polymer/lib/legacy/class.js'; import {IronValidatorBehavior} from '@polymer/iron-validator-behavior/iron-validator-behavior.js'; class SampleValidator extends mixinBehaviors([IronValidatorBehavior], PolymerElement){ // This validator only validates strings, and is only valid if // the value is "cat". function validate(value) { return value === 'cat'; } } customElements.define('sample-validator', SampleValidator); ``` ### Using this validator element in an html file ```html ``` ## Contributing If you want to send a PR to this element, here are the instructions for running the tests and demo locally: ### Installation ```sh git clone https://github.com/PolymerElements/iron-validator-behavior cd iron-validator-behavior npm install npm install -g polymer-cli ``` ### Running the demo locally ```sh polymer serve --npm open http://127.0.0.1:/demo/ ``` ### Running the tests ```sh polymer test --npm ```