Aurelia autocomplete

app.html

<template>
  <require from="./autocomplete"></require>
  <form>
    <label class="form-component">
      Country
      <autocomplete service.bind="countryNameService" 
                    value.bind="countryName"
                    placeholder="Country">
      </autocomplete>
    </label>
    
    <label class="form-component">
      Country 2
      <autocomplete service.bind="countryService" 
                    value.bind="country"
                    placeholder="Country">
        <template replace-part="suggestion">
          ${suggestion.code}: ${suggestion.name}
        </template>
      </autocomplete>
    </label>
  </form>
</template>

app.js

import {countries} from './countries';

export class App {
  countryNameService = new CountryNameSuggestionService();
  countryName = null;
  
  countryService = new CountrySuggestionService();
  country = null;
}

export class CountryNameSuggestionService {
  suggest(value) {
    if (value === '') {
      return Promise.resolve([]);
    }
    value = value.toLowerCase();
    const suggestions = countries.filter(x => x.name.toLowerCase().indexOf(value) === 0)
      .map(x => x.name);
    return Promise.resolve(suggestions);
  }
  
  getName(suggestion) {
    return suggestion;
  }
}

export class CountrySuggestionService {
  suggest(value) {
    if (value === '') {
      return Promise.resolve([]);
    }
    value = value.toLowerCase();
    const suggestions = countries.filter(x => x.name.toLowerCase().indexOf(value) === 0);
    return Promise.resolve(suggestions);
  }
  
  getName(suggestion) {
    return suggestion.name;
  }
}

autocomplete.css

autocomplete {
  display: inline-block;
}

autocomplete .suggestions {
  list-style-type: none;
  cursor: default;
  padding: 0;
  margin: 0;
  border: 1px solid #ccc;
  background: #fff;
  box-shadow: -1px 1px 3px rgba(0,0,0,.1);
  
  position: absolute;
  z-index: 9999; 
  max-height: 15rem; 
  overflow: hidden; 
  overflow-y: auto; 
  box-sizing: border-box;
}

autocomplete .suggestion {
  padding: 0 .3rem;
  line-height: 1.5rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  color: #333;
}

autocomplete .suggestion:hover,
autocomplete .suggestion.selected { 
  background: #f0f0f0;
}

autocomplete.html

<template>
  <require from="./autocomplete.css"></require>

  <input type="text" autocomplete="off"
         aria-autocomplete="list"
         aria-expanded.bind="expanded"
         aria-owns.one-time="'au-autocomplate-' + id + '-suggestions'"
         aria-activedescendant.bind="index >= 0 ? 'au-autocomplate-' + id + '-suggestion-' + index : ''"
         id.one-time="'au-autocomplete-' + id"
         placeholder.bind="placeholder"
         value.bind="inputValue & debounce:delay"
         keydown.delegate="keydown($event.which)"
         blur.trigger="blur()">
  <ul class="suggestions" role="listbox"
      if.bind="expanded"
      id.one-time="'au-autocomplate-' + id + '-suggestions'"
      ref="suggestionsUL">
    <li repeat.for="suggestion of suggestions" 
        id.one-time="'au-autocomplate-' + id + '-suggestion-' + $index"
        role="option"
        class-name.bind="($index === index ? 'selected' : '') + ' suggestion'"
        mousedown.delegate="suggestionClicked(suggestion)">
      <template replaceable part="suggestion">
        ${suggestion}
      </template>
    </li>
  </ul>
</template>

autocomplete.js

import {bindingMode, observable} from 'aurelia-binding';
import {bindable} from 'aurelia-templating';
import {inject} from 'aurelia-dependency-injection';
import {DOM} from 'aurelia-pal';

let nextID = 0;

@inject(Element)
export class Autocomplete {
  @bindable service;
  @bindable({ defaultBindingMode: bindingMode.twoWay }) value;
  @bindable placeholder = '';
  @bindable delay = 300;
  id = nextID++;
  expanded = false;
  @observable inputValue = '';
  updatingInput = false;
  suggestions = [];
  index = -1;
  suggestionsUL = null;
  userInput = '';
  
  constructor(element) {
    this.element = element;
  }
  
  display(name) {
    this.updatingInput = true;
    this.inputValue = name;
    this.updatingInput = false;
  }
  
  getName(suggestion) {
    if (suggestion == null) {
      return '';
    }
    return this.service.getName(suggestion);
  }
  
  collapse() {
    this.expanded = false;
    this.index = -1;
  }
  
  select(suggestion) {
    this.value = suggestion;
    const name = this.getName(this.value);
    this.userInput = name;
    this.display(name);
    this.collapse();
  }
  
  valueChanged() {
    this.select(this.value);
  }
  
  inputValueChanged(value) {
    if (this.updatingInput) {
      return;
    }
    this.userInput = value;
    if (value === '') {
      this.value = null;
      this.collapse();
      return;
    }
    this.service.suggest(value)
      .then(suggestions => {
        this.index = -1;
        this.suggestions.splice(0, this.suggestions.length, ...suggestions);
        if (suggestions.length === 1) {
          this.select(suggestions[0]);
        } else if (suggestions.length === 0) {
          this.collapse();
        } else {
          this.expanded = true;
        }
      });
  }
  
  scroll() {
    const ul = this.suggestionsUL;
    const li = ul.children.item(this.index === -1 ? 0 : this.index);
    if (li.offsetTop + li.offsetHeight > ul.offsetHeight) {
      ul.scrollTop += li.offsetHeight;
    } else if(li.offsetTop < ul.scrollTop) {
      ul.scrollTop = li.offsetTop;
    }
  }
  
  keydown(key) {
    if (!this.expanded) {
      return true;
    }
    
    // down
    if (key === 40) {
      if (this.index < this.suggestions.length - 1) {
        this.index++;
        this.display(this.getName(this.suggestions[this.index]));
      } else {
        this.index = -1;
        this.display(this.userInput);
      } 
      this.scroll();
      return;
    }
    
    // up
    if (key === 38) {
      if (this.index === -1) {
        this.index = this.suggestions.length - 1;
        this.display(this.getName(this.suggestions[this.index]));
      } else if (this.index > 0) {
        this.index--;
        this.display(this.getName(this.suggestions[this.index]));
      } else {
        this.index = -1;
        this.display(this.userInput);
      }
      this.scroll();
      return;  
    }
    
    // escape
    if (key === 27) {
      this.display(this.userInput);
      this.collapse();
      return;
    }
    
    // enter
    if (key === 13) {
      if (this.index >= 0) {
        this.select(this.suggestions[this.index]);
      }
      return;
    }
    
    return true;
  }
  
  blur() {
    this.select(this.value);
    this.element.dispatchEvent(DOM.createCustomEvent('blur'));
  }
  
  suggestionClicked(suggestion) {
    this.select(suggestion);
  }
  
  focus() {
    this.element.firstElementChild.focus();
  }
}

// aria-activedescendant
// https://webaccessibility.withgoogle.com/unit?unit=6&lesson=13
// https://www.w3.org/TR/wai-aria/states_and_properties#aria-autocomplete
// https://www.w3.org/TR/wai-aria/roles#combobox

countries.js

export const countries = [ 
  {name: 'Afghanistan', code: 'AF'}, 
  {name: 'Åland Islands', code: 'AX'}, 
  {name: 'Albania', code: 'AL'}, 
  {name: 'Algeria', code: 'DZ'}, 
  {name: 'American Samoa', code: 'AS'}, 
  {name: 'AndorrA', code: 'AD'}, 
  {name: 'Angola', code: 'AO'}, 
  {name: 'Anguilla', code: 'AI'}, 
  {name: 'Antarctica', code: 'AQ'}, 
  {name: 'Antigua and Barbuda', code: 'AG'}, 
  {name: 'Argentina', code: 'AR'}, 
  {name: 'Armenia', code: 'AM'}, 
  {name: 'Aruba', code: 'AW'}, 
  {name: 'Australia', code: 'AU'}, 
  {name: 'Austria', code: 'AT'}, 
  {name: 'Azerbaijan', code: 'AZ'}, 
  {name: 'Bahamas', code: 'BS'}, 
  {name: 'Bahrain', code: 'BH'}, 
  {name: 'Bangladesh', code: 'BD'}, 
  {name: 'Barbados', code: 'BB'}, 
  {name: 'Belarus', code: 'BY'}, 
  {name: 'Belgium', code: 'BE'}, 
  {name: 'Belize', code: 'BZ'}, 
  {name: 'Benin', code: 'BJ'}, 
  {name: 'Bermuda', code: 'BM'}, 
  {name: 'Bhutan', code: 'BT'}, 
  {name: 'Bolivia', code: 'BO'}, 
  {name: 'Bosnia and Herzegovina', code: 'BA'}, 
  {name: 'Botswana', code: 'BW'}, 
  {name: 'Bouvet Island', code: 'BV'}, 
  {name: 'Brazil', code: 'BR'}, 
  {name: 'British Indian Ocean Territory', code: 'IO'}, 
  {name: 'Brunei Darussalam', code: 'BN'}, 
  {name: 'Bulgaria', code: 'BG'}, 
  {name: 'Burkina Faso', code: 'BF'}, 
  {name: 'Burundi', code: 'BI'}, 
  {name: 'Cambodia', code: 'KH'}, 
  {name: 'Cameroon', code: 'CM'}, 
  {name: 'Canada', code: 'CA'}, 
  {name: 'Cape Verde', code: 'CV'}, 
  {name: 'Cayman Islands', code: 'KY'}, 
  {name: 'Central African Republic', code: 'CF'}, 
  {name: 'Chad', code: 'TD'}, 
  {name: 'Chile', code: 'CL'}, 
  {name: 'China', code: 'CN'}, 
  {name: 'Christmas Island', code: 'CX'}, 
  {name: 'Cocos (Keeling) Islands', code: 'CC'}, 
  {name: 'Colombia', code: 'CO'}, 
  {name: 'Comoros', code: 'KM'}, 
  {name: 'Congo', code: 'CG'}, 
  {name: 'Congo, The Democratic Republic of the', code: 'CD'}, 
  {name: 'Cook Islands', code: 'CK'}, 
  {name: 'Costa Rica', code: 'CR'}, 
  {name: 'Cote D\'Ivoire', code: 'CI'}, 
  {name: 'Croatia', code: 'HR'}, 
  {name: 'Cuba', code: 'CU'}, 
  {name: 'Cyprus', code: 'CY'}, 
  {name: 'Czech Republic', code: 'CZ'}, 
  {name: 'Denmark', code: 'DK'}, 
  {name: 'Djibouti', code: 'DJ'}, 
  {name: 'Dominica', code: 'DM'}, 
  {name: 'Dominican Republic', code: 'DO'}, 
  {name: 'Ecuador', code: 'EC'}, 
  {name: 'Egypt', code: 'EG'}, 
  {name: 'El Salvador', code: 'SV'}, 
  {name: 'Equatorial Guinea', code: 'GQ'}, 
  {name: 'Eritrea', code: 'ER'}, 
  {name: 'Estonia', code: 'EE'}, 
  {name: 'Ethiopia', code: 'ET'}, 
  {name: 'Falkland Islands (Malvinas)', code: 'FK'}, 
  {name: 'Faroe Islands', code: 'FO'}, 
  {name: 'Fiji', code: 'FJ'}, 
  {name: 'Finland', code: 'FI'}, 
  {name: 'France', code: 'FR'}, 
  {name: 'French Guiana', code: 'GF'}, 
  {name: 'French Polynesia', code: 'PF'}, 
  {name: 'French Southern Territories', code: 'TF'}, 
  {name: 'Gabon', code: 'GA'}, 
  {name: 'Gambia', code: 'GM'}, 
  {name: 'Georgia', code: 'GE'}, 
  {name: 'Germany', code: 'DE'}, 
  {name: 'Ghana', code: 'GH'}, 
  {name: 'Gibraltar', code: 'GI'}, 
  {name: 'Greece', code: 'GR'}, 
  {name: 'Greenland', code: 'GL'}, 
  {name: 'Grenada', code: 'GD'}, 
  {name: 'Guadeloupe', code: 'GP'}, 
  {name: 'Guam', code: 'GU'}, 
  {name: 'Guatemala', code: 'GT'}, 
  {name: 'Guernsey', code: 'GG'}, 
  {name: 'Guinea', code: 'GN'}, 
  {name: 'Guinea-Bissau', code: 'GW'}, 
  {name: 'Guyana', code: 'GY'}, 
  {name: 'Haiti', code: 'HT'}, 
  {name: 'Heard Island and Mcdonald Islands', code: 'HM'}, 
  {name: 'Holy See (Vatican City State)', code: 'VA'}, 
  {name: 'Honduras', code: 'HN'}, 
  {name: 'Hong Kong', code: 'HK'}, 
  {name: 'Hungary', code: 'HU'}, 
  {name: 'Iceland', code: 'IS'}, 
  {name: 'India', code: 'IN'}, 
  {name: 'Indonesia', code: 'ID'}, 
  {name: 'Iran, Islamic Republic Of', code: 'IR'}, 
  {name: 'Iraq', code: 'IQ'}, 
  {name: 'Ireland', code: 'IE'}, 
  {name: 'Isle of Man', code: 'IM'}, 
  {name: 'Israel', code: 'IL'}, 
  {name: 'Italy', code: 'IT'}, 
  {name: 'Jamaica', code: 'JM'}, 
  {name: 'Japan', code: 'JP'}, 
  {name: 'Jersey', code: 'JE'}, 
  {name: 'Jordan', code: 'JO'}, 
  {name: 'Kazakhstan', code: 'KZ'}, 
  {name: 'Kenya', code: 'KE'}, 
  {name: 'Kiribati', code: 'KI'}, 
  {name: 'Korea, Democratic People\'S Republic of', code: 'KP'}, 
  {name: 'Korea, Republic of', code: 'KR'}, 
  {name: 'Kuwait', code: 'KW'}, 
  {name: 'Kyrgyzstan', code: 'KG'}, 
  {name: 'Lao People\'S Democratic Republic', code: 'LA'}, 
  {name: 'Latvia', code: 'LV'}, 
  {name: 'Lebanon', code: 'LB'}, 
  {name: 'Lesotho', code: 'LS'}, 
  {name: 'Liberia', code: 'LR'}, 
  {name: 'Libyan Arab Jamahiriya', code: 'LY'}, 
  {name: 'Liechtenstein', code: 'LI'}, 
  {name: 'Lithuania', code: 'LT'}, 
  {name: 'Luxembourg', code: 'LU'}, 
  {name: 'Macao', code: 'MO'}, 
  {name: 'Macedonia, The Former Yugoslav Republic of', code: 'MK'}, 
  {name: 'Madagascar', code: 'MG'}, 
  {name: 'Malawi', code: 'MW'}, 
  {name: 'Malaysia', code: 'MY'}, 
  {name: 'Maldives', code: 'MV'}, 
  {name: 'Mali', code: 'ML'}, 
  {name: 'Malta', code: 'MT'}, 
  {name: 'Marshall Islands', code: 'MH'}, 
  {name: 'Martinique', code: 'MQ'}, 
  {name: 'Mauritania', code: 'MR'}, 
  {name: 'Mauritius', code: 'MU'}, 
  {name: 'Mayotte', code: 'YT'}, 
  {name: 'Mexico', code: 'MX'}, 
  {name: 'Micronesia, Federated States of', code: 'FM'}, 
  {name: 'Moldova, Republic of', code: 'MD'}, 
  {name: 'Monaco', code: 'MC'}, 
  {name: 'Mongolia', code: 'MN'}, 
  {name: 'Montserrat', code: 'MS'}, 
  {name: 'Morocco', code: 'MA'}, 
  {name: 'Mozambique', code: 'MZ'}, 
  {name: 'Myanmar', code: 'MM'}, 
  {name: 'Namibia', code: 'NA'}, 
  {name: 'Nauru', code: 'NR'}, 
  {name: 'Nepal', code: 'NP'}, 
  {name: 'Netherlands', code: 'NL'}, 
  {name: 'Netherlands Antilles', code: 'AN'}, 
  {name: 'New Caledonia', code: 'NC'}, 
  {name: 'New Zealand', code: 'NZ'}, 
  {name: 'Nicaragua', code: 'NI'}, 
  {name: 'Niger', code: 'NE'}, 
  {name: 'Nigeria', code: 'NG'}, 
  {name: 'Niue', code: 'NU'}, 
  {name: 'Norfolk Island', code: 'NF'}, 
  {name: 'Northern Mariana Islands', code: 'MP'}, 
  {name: 'Norway', code: 'NO'}, 
  {name: 'Oman', code: 'OM'}, 
  {name: 'Pakistan', code: 'PK'}, 
  {name: 'Palau', code: 'PW'}, 
  {name: 'Palestinian Territory, Occupied', code: 'PS'}, 
  {name: 'Panama', code: 'PA'}, 
  {name: 'Papua New Guinea', code: 'PG'}, 
  {name: 'Paraguay', code: 'PY'}, 
  {name: 'Peru', code: 'PE'}, 
  {name: 'Philippines', code: 'PH'}, 
  {name: 'Pitcairn', code: 'PN'}, 
  {name: 'Poland', code: 'PL'}, 
  {name: 'Portugal', code: 'PT'}, 
  {name: 'Puerto Rico', code: 'PR'}, 
  {name: 'Qatar', code: 'QA'}, 
  {name: 'Reunion', code: 'RE'}, 
  {name: 'Romania', code: 'RO'}, 
  {name: 'Russian Federation', code: 'RU'}, 
  {name: 'RWANDA', code: 'RW'}, 
  {name: 'Saint Helena', code: 'SH'}, 
  {name: 'Saint Kitts and Nevis', code: 'KN'}, 
  {name: 'Saint Lucia', code: 'LC'}, 
  {name: 'Saint Pierre and Miquelon', code: 'PM'}, 
  {name: 'Saint Vincent and the Grenadines', code: 'VC'}, 
  {name: 'Samoa', code: 'WS'}, 
  {name: 'San Marino', code: 'SM'}, 
  {name: 'Sao Tome and Principe', code: 'ST'}, 
  {name: 'Saudi Arabia', code: 'SA'}, 
  {name: 'Senegal', code: 'SN'}, 
  {name: 'Serbia and Montenegro', code: 'CS'}, 
  {name: 'Seychelles', code: 'SC'}, 
  {name: 'Sierra Leone', code: 'SL'}, 
  {name: 'Singapore', code: 'SG'}, 
  {name: 'Slovakia', code: 'SK'}, 
  {name: 'Slovenia', code: 'SI'}, 
  {name: 'Solomon Islands', code: 'SB'}, 
  {name: 'Somalia', code: 'SO'}, 
  {name: 'South Africa', code: 'ZA'}, 
  {name: 'South Georgia and the South Sandwich Islands', code: 'GS'}, 
  {name: 'Spain', code: 'ES'}, 
  {name: 'Sri Lanka', code: 'LK'}, 
  {name: 'Sudan', code: 'SD'}, 
  {name: 'Suriname', code: 'SR'}, 
  {name: 'Svalbard and Jan Mayen', code: 'SJ'}, 
  {name: 'Swaziland', code: 'SZ'}, 
  {name: 'Sweden', code: 'SE'}, 
  {name: 'Switzerland', code: 'CH'}, 
  {name: 'Syrian Arab Republic', code: 'SY'}, 
  {name: 'Taiwan, Province of China', code: 'TW'}, 
  {name: 'Tajikistan', code: 'TJ'}, 
  {name: 'Tanzania, United Republic of', code: 'TZ'}, 
  {name: 'Thailand', code: 'TH'}, 
  {name: 'Timor-Leste', code: 'TL'}, 
  {name: 'Togo', code: 'TG'}, 
  {name: 'Tokelau', code: 'TK'}, 
  {name: 'Tonga', code: 'TO'}, 
  {name: 'Trinidad and Tobago', code: 'TT'}, 
  {name: 'Tunisia', code: 'TN'}, 
  {name: 'Turkey', code: 'TR'}, 
  {name: 'Turkmenistan', code: 'TM'}, 
  {name: 'Turks and Caicos Islands', code: 'TC'}, 
  {name: 'Tuvalu', code: 'TV'}, 
  {name: 'Uganda', code: 'UG'}, 
  {name: 'Ukraine', code: 'UA'}, 
  {name: 'United Arab Emirates', code: 'AE'}, 
  {name: 'United Kingdom', code: 'GB'}, 
  {name: 'United States', code: 'US'}, 
  {name: 'United States Minor Outlying Islands', code: 'UM'}, 
  {name: 'Uruguay', code: 'UY'}, 
  {name: 'Uzbekistan', code: 'UZ'}, 
  {name: 'Vanuatu', code: 'VU'}, 
  {name: 'Venezuela', code: 'VE'}, 
  {name: 'Viet Nam', code: 'VN'}, 
  {name: 'Virgin Islands, British', code: 'VG'}, 
  {name: 'Virgin Islands, U.S.', code: 'VI'}, 
  {name: 'Wallis and Futuna', code: 'WF'}, 
  {name: 'Western Sahara', code: 'EH'}, 
  {name: 'Yemen', code: 'YE'}, 
  {name: 'Zambia', code: 'ZM'}, 
  {name: 'Zimbabwe', code: 'ZW'} 
];

index.html

<!doctype html>
<html>
  <head>
    <title>Aurelia</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/meyer-reset/2.0/reset.min.css">
    <style>
      .form-component {
        display: block;
      }
    </style>
  </head>
  <body aurelia-app>
    <h1>Loading...</h1>
    
    <script src="https://jdanyow.github.io/rjs-bundle/node_modules/requirejs/require.js"></script>
    <script src="https://jdanyow.github.io/rjs-bundle/config.js"></script>
    <script src="https://jdanyow.github.io/rjs-bundle/bundles/aurelia.js"></script>
    <script src="https://jdanyow.github.io/rjs-bundle/bundles/babel.js"></script>
    <script>
      require(['aurelia-bootstrapper']);
    </script>
  </body>
</html>

Great Job @jdanyow! Just curious how can you avoid filling the input box if only one value matches the entry. Basically, give the ability to user to input stuff that are not in the suggestion list.

change:

  blur() {
-    this.select(this.value);
+    this.select(this.inputValue);
    this.element.dispatchEvent(DOM.createCustomEvent('blur'));
  }

here's an updated version of the control:

https://gist.run/?id=acf8253329939b2e046cd0e3394351fe