emberx-select

A select component based on the native html select.

We've tried other select components, and were missing the reliability, maintainability, and accessbility of the native html <select>. <XSelect> is a drop-in component to let you use any object for your selectable options. You can use it out of the box, or as a building block of something more ambitious.

The goal of <XSelect> is to let you see how it works and style it right in your template, rather than passing in a ball of configuration or wrapping a hard-coded, inaccessible jQuery plugin.

Installation

ember install emberx-select

Usage

By allowing arbitrary html to appear in the template of the select element, you can use it just like you would normally. This means things like having <optgroup> tags inside your select, or even plain old <option> elements to represent things like empty values.

<XSelect> thinly wraps a native <select> element so that it can be object and binding aware. It is used in conjuction with the x-option component to construct select boxes. E.g.

Ember >= 3.4:

<XSelect @value={{bob}} @onChange={{action "selectPerson"}} as |xs|>
  <xs.option @value={{fred}}>Fred Flintstone</xs.option>
  <xs.option @value={{bob}}>Bob Newhart</xs.option>
</XSelect>

Ember < 3.4:

{{#x-select value=bob on-change=(action "selectPerson") as |xs|}}
  {{#xs.option value=fred}}Fred Flintstone{{/xs.option}}
  {{#xs.option value=bob}}Bob Newhart{{/xs.option}}
{{/x-select}}

The options are always up to date, so that when the object bound to value changes, the corresponding option becomes selected.

Whenever the select tag receives a change event, it will fire onChange action. This is the default action that is fired but not the only event that's available.

Contextual Components

As of version 3.0.0, emberx-select will only support contextual components. This means you will have to use Ember 2.3 or higher. Using contextual components allows emberx-select to skip some potentially expensive DOM traversals. Now the options can register through data rather than through the DOM.

<XSelect @value={{model.status}} as |xs|>
  <xs.option @value=1>Active</xs.option>
  <xs.option @value=2>Inactive</xs.option>
</XSelect>

Multiselect

<XSelect> supports the multiple option. This means you can pass an array as its value, and it will set its selections directly on that array.

<XSelect @value=selections @multiple=true @onChange={{action "selectionsChanged"}} as |xs|>
 <xs.option @value={{fred}}>Fred Flintstone</xs.option>
 <xs.option @value={{bob}}>Bob Newhart</xs.option>
 <xs.option @value={{andrew}}>Andrew WK</xs.option>
</XSelect>

The selections array will be initialized to an empty array if not present.

Actions and Action Arguments

All of <XSelect>s actions are closure actions. This means you must use the action helper (i.e. @onClick={{action "onClick"}}). The function that is dispatched by <XSelect> whenever the event fires has a function signature of:

/**
* @param {Object} value - the value selected by the user.
* @param {Object} event - the DOM event of the action
*/
function (value, event) {
  // action body...
}

Most of the time all you need is the value that has been selected, but sometimes your action requires more context than just that. In those cases, you can pass any arguments you need from the template. For example:

<XSelect @onClick={{action "didMakeSelection" isXSelectRequired}} @required={{isXSelectRequired}} as |xs|>
  <option>Nothing</option>
  <xs.option @value={{something}}>Something</xs.option>
</XSelect>

then, inside your action handler:

import Controller from '@ember/controller';

export default Controller.extend({
  actions: {
    didMakeSelection(value, event, isXSelectRequired) {
      if (!value & isXSelectRequired) {
        this.set('error', 'You must fill out this field');
      } else {
        this.set('selection', value);
      }
    }
  }
});

<XSelect> provides other actions that fire on different event types. These actions follow the HTML input event naming convention.

onBlur

onBlur fires anytime the blur event is triggered on the <XSelect> component. When the action fires it sends two arguments: the value, the DOM event.

onFocusOut

onFocusOut fires anytime the focusOut event is triggered on the <XSelect> component. When the action fires it sends two arguments: the value, the DOM event.

onClick

onClick fires when <XSelect> is clicked. When the action fires it sends two arguments: the value, the DOM event.

onDisable (x-option)

onDisable fires when x-option detects a change to its disabled attribute. When the action fires it sends two arguments: the value and if it is disabled (boolean).

Test Helper

<XSelect> 4.0 ships with an entirely new test helper that goes beyond just allowing you to select an option. It allows you to interact with your <select> element in all different ways. For example, if you need to assert your first option is disabled or not:

expect(xselect.options(0).isDisabled).to.equal(true);

Under the hood this new test helper is using a BigTest Interactor. Interactors allow you to think about how you're going to interact with the DOM and abstract that into composable & immutable containers. Interactors are similar to page objects, but for components.

Using the test helper

Import the select interactor:

// you can name the import whatever you want
import XSelectInteractor from 'emberx-select/test-support/interactor';

At the top of your test file you need to initialize the interactor. This should go at the top most part of your test so it's available to all tests in the file. Here's an example in Qunit:

module("Acceptance | Your Test", function(hooks) {
  let xselect = new XSelectInteractor('.selector-for-select');
  setupApplicationTest(hooks);
  // ...
});

Once you have initialized the interactor, you're ready to start selecting!

module("Acceptance | Your Test", function(hooks) {
  let xselect = new XSelectInteractor('.selector-for-select');
  // ...

  test('Selecting an option', async (assert) => {
    await xselect
      .select('Fred Flintstone')
      .when(() => assert.equal(xselect.options(0).isSelected, true));

    // for a multiselect pass an array
    // await xselect
    //   .select(['Fred Flintstone', 'Bob Newhart'])
    //   .when(() => assert.equal(xselect.options(0).isSelected, true));;
  });
});

You can do more than just select options with this helper.

module('Acceptance | Your Test', function(hooks) {
  let xselect = new XSelectInteractor('.selector-for-select');
  // ...

  test('Selecting an option', async (assert) => {
    await xselect.select('Fred Flintstone')
      // assert the change is has happened. It's important to make the
      // assertion inside of `when`, so tests are not flakey.
      .when(() => assert.equal(xselect.options(0).isSelected, true));
  });
});

In this example we're using @bigtest/convergence#when to assert. The TL;DR of convergence is it basically converges on the state of the DOM. It checks every 10ms until the assertion is truthy. Once it's truthy the test passes. You can read more about convergences here

You don't need to include @bigtest/convergence in your project, it's already a dependency of @bigtest/interactor and interactor provides all of the convergence methods to you (like when and do).

This is the full interactor which has all of the attributes or interactions for an HTMLSelectElement.

const xSelectInteractor = interactor({
  hasFocus: is(':focus'),
  name: attribute('name'),
  form: attribute('form'),
  title: attribute('title'),
  size: attribute('size'),
  tabindex: attribute('tabindex'),
  isDisabled: property('disabled'),
  isRequired: property('required'),
  isAutofocus: property('autofocus'),

  options: collection('option', {
    name: attribute('name'),
    value: property('value'),
    title: attribute('title'),
    isSelected: property('selected'),
    isDisabled: property('disabled'),
    hasSelectedClass: hasClass('is-selected')
  })
});

Example usage might be:

<select name="World" class="x-select">
  <option value="hello world">Hello world!</option>
</select>

let xselect = new XSelectInteractor('.x-select');

xselect.options(0).value; //=> "hello world"
xselect.options(0).text; //=> "Hello World!"
xselect.name; //=> "World"
xselect.form; //=> null
xselect.hasFocus; //=> false
xselect.tabIndex; //=> 0

If you want to see this test helper used in many different ways look no further than this addons test suite!

Extending the XSelect interactor

If you want to add custom interactions to your <XSelect> interactor, you can do so by importing it into the custom interactor you want to create, and extend it:

import XSelectInteractor from 'emberx-select/test-support/interactor';
import { clickable } from '@bigtest/interactor';

@XSelectInteractor.extend
class NewInteractor {
  submitForm = clickable('[data-test-form-submit]');

  fillAndSubmit(value) {
    return this.select(value).submitForm();
  }
}

EmberX

emberx-select is part of the "missing components of ember" collectively known as emberx:

Other Resources

EmberScreencasts video on creating select boxes with vanilla Ember and emberx-select

Running Tests

ember test
ember test --server

Release Process

Every commit to master results in a build and push to the demo application at http://emberx-select.netlify.com

Npm releases use semver and happen at the project owner's discretion.

Code of Conduct

Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms, which can be found in the CODE_OF_CONDUCT.md file in this repository.

adopted-ember-addons / emberx-select

readme