Choices.js Stimulus wrapper preview

README.md

Choices.js Stimulus wrapper

https://joshuajohnson.co.uk/Choices/

Soon, this will be published as an NPM package, but there's an absence of documentation right now. It supports almost all functions from the original library; soon it will support 100% of them.

This wrapper adds Ajax pre-fetch search. Happens if controller has a data-search-path attribute.

Stimulus controller targets use new v2 syntax. Controller attaches a reference to itself on the element so that you can access the internal state from external scripts.

Verified to support single and multi-select drop-downs.

You can pre-populate options into the datalist.

Full compatibility with Turbolinks 5/6 including page caching.

choices_controller.js

import { Controller } from 'stimulus'
import * as Choices from 'choices.js'

export default class extends Controller {
  static targets = ['select', 'options']

  initialize () {
    this.element['choices'] = this
    this.refresh = this.refresh.bind(this)
    this.add = this.add.bind(this)
    this.remove = this.remove.bind(this)
    this.search = this.search.bind(this)
    this.update = this.update.bind(this)
    this.filter = this.filter.bind(this)
    this.options = this.options.bind(this)
    this.optionsReducer = this.optionsReducer.bind(this)
    this.searchPath = this.element.dataset.searchPath
    this.forceOption = this.element.dataset.forceOption || true
  }

  connect () {
    setTimeout(this.setup.bind(this), 5)
  }

  setup () {
    this.choices = new Choices(this.selectTarget, this.options())
    this.input = this.element.querySelector('input')
    this.refresh()
    if (this.searchPath) this.input.addEventListener('input', this.search)
    this.selectTarget.addEventListener('change', this.refresh)
    this.selectTarget.addEventListener('addItem', this.add)
    this.selectTarget.addEventListener('removeItem', this.remove)
  }

  disconnect () {
    if (this.searchPath) this.input.removeEventListener('input', this.search)
    this.selectTarget.removeEventListener('change', this.refresh)
    this.selectTarget.removeEventListener('addItem', this.add)
    this.selectTarget.removeEventListener('removeItem', this.remove)
    try {
      this.choices.destroy()
    } catch {}
    this.choices = undefined
  }

  refresh () {
    this.choices.setChoices([], 'value', 'label', true)
    if (this.hasOptionsTarget) {
      ;[...this.optionsTarget.children].forEach(this.append.bind(this))
    }
  }

  append (option) {
    if (
      ![...this.selectTarget.options].some(o => {
        return o.label === option.label
      })
    )
      this.choices.setChoices([option], 'value', 'label', false)
  }

  add (event) {
    if (this.hasOptionsTarget) {
      const option = [...this.optionsTarget.children].find(option => {
        return option.label === event.detail.label
      })
      if (option) {
        option.setAttribute('selected', '')
      } else {
        const newOption = document.createElement('option')
        newOption.setAttribute('label', event.detail.label)
        newOption.setAttribute('value', event.detail.value)
        newOption.setAttribute('selected', '')
        this.optionsTarget.appendChild(newOption)
      }
    }
  }

  remove (event) {
    if (this.hasOptionsTarget) {
      const option = [...this.optionsTarget.children].find(item => {
        return item.label === event.detail.label
      })
      if (option)
        this.searchPath ? option.remove() : option.removeAttribute('selected')
    }
    if (this.forceOption && !this.selectTarget.options.length)
      this.selectTarget.add(document.createElement('option'))
  }

  search (event) {
    if (event.target.value) {
      fetch(this.searchPath + event.target.value, {
        headers: { 'X-Requested-With': 'XMLHttpRequest' }
      })
        .then(response => response.json())
        .then(this.update)
    } else {
      this.refresh()
    }
  }

  update (data) {
    this.choices.setChoices(data.filter(this.filter), 'value', 'label', true)
  }

  filter (item) {
    return ![...this.selectTarget.options].some(option => {
      return option.label === item.label
    })
  }

  options () {
    return 'silent renderChoiceLimit maxItemCount addItems removeItems removeItemButton editItems duplicateItemsAllowed delimiter paste searchEnabled searchChoices searchFloor searchResultLimit position resetScrollPosition addItemFilter shouldSort shouldSortItems placeholder placeholderValue prependValue appendValue renderSelectedChoices loadingText noResultsText noChoicesText itemSelectText addItemText maxItemText'
      .split(' ')
      .reduce(this.optionsReducer, {})
  }

  optionsReducer (accumulator, currentValue) {
    if (this.element.dataset[currentValue])
      accumulator[currentValue] = this.element.dataset[currentValue]
    return accumulator
  }
}

event.rb

class Event < ApplicationRecord
  # gem "pg_search", "~> 2.3" # https://github.com/Casecommons/pg_search
  include PgSearch::Model
  pg_search_scope :stemmed, against: :name, using: {tsearch: {prefix: true}, trigram: {}}
  def self.typeahead_search(term)
    Event
      .stemmed(term)
      .map { |event| {value: event.id, label: event.name} }
  end
end

events_controller.rb

class EventsController < ApplicationController
  skip_before_action :verify_authenticity_token, only: [:search]

  def search
    render json: Event.typeahead_search(params[:name])
  end
end

multi.html.erb

<div data-controller="choices" data-search-path="/events/search?name=" data-remove-item-button="true" data-duplicate-items-allowed="false" data-search-result-limit="100" data-no-choices-text="Start typing to search...">
  <datalist data-choices-target="options"></datalist>
  <select data-choices-target="select"></select>
</div>

routes.rb

Rails.application.routes.draw do
  resources :events do
    collection do
      get "search", constraints: lambda { |request| request.xhr? }
    end
  end
end

single.html.erb

<div data-controller="choices" data-search-path="/events/search?name=" data-remove-item-button="true" data-search-result-limit="100" data-no-choices-text="Start typing to search...">
  <datalist data-choices-target="options"></datalist>
  <%= f.collection_select :event_id, @events, :id, :name, {include_blank: true}, {data: {"choices-target": "select"}} %>
</div>