@ng-select/ng-select

What is @ng-select/ng-select?

@ng-select/ng-select is a highly customizable Angular component for creating select dropdowns. It provides a wide range of features including single and multiple selection, custom templates, filtering, and more.

What are @ng-select/ng-select's main functionalities?

Single Selection

This feature allows users to select a single item from a dropdown list. The `items` input takes an array of objects, and `bindLabel` specifies the property to display in the dropdown.

<ng-select [items]="cities" bindLabel="name" placeholder="Select a city"></ng-select>

Multiple Selection

This feature enables users to select multiple items from the dropdown. Setting the `multiple` input to `true` allows for multiple selections.

<ng-select [items]="cities" bindLabel="name" [multiple]="true" placeholder="Select cities"></ng-select>

Custom Templates

Custom templates allow for more control over the appearance of the dropdown items. The `ng-option-tmp` directive can be used to define a custom template for each item.

<ng-select [items]="cities" bindLabel="name" placeholder="Select a city">
  <ng-template ng-option-tmp let-item="item" let-index="index">
    <div class="custom-option">
      <span>{{item.name}}</span>
    </div>
  </ng-template>
</ng-select>

Filtering

The filtering feature allows users to search through the dropdown items. Setting the `searchable` input to `true` enables this functionality.

<ng-select [items]="cities" bindLabel="name" [searchable]="true" placeholder="Select a city"></ng-select>

Async Data

This feature supports loading data asynchronously. The `items` input can take an observable, and the dropdown will update as the data is loaded.

<ng-select [items]="cities$ | async" bindLabel="name" placeholder="Select a city"></ng-select>

Other packages similar to @ng-select/ng-select

ngx-select-dropdown

ngx-select-dropdown is another Angular package for creating dropdowns. It offers similar functionalities such as single and multiple selection, custom templates, and filtering. However, it may not be as feature-rich or customizable as @ng-select/ng-select.

ng-multiselect-dropdown

ng-multiselect-dropdown is focused on providing a multi-select dropdown component for Angular. It supports features like filtering and custom templates but is primarily designed for multiple selections, unlike @ng-select/ng-select which supports both single and multiple selections.

angular-ng-autocomplete

angular-ng-autocomplete is an Angular component for creating autocomplete dropdowns. It provides features like filtering and custom templates, similar to @ng-select/ng-select, but is more focused on autocomplete functionality rather than general dropdowns.

README

Angular ng-select - Lightweight all in one UI Select, Multiselect and Autocomplete

See Demo page.

---

Versions

Angular	ng-select
>=12.0.0 <13.0.0	v7.x
>=11.0.0 <12.0.0	v6.x
>=10.0.0 <11.0.0	v5.x
>=9.0.0 <10.0.0	v4.x
>=8.0.0 <9.0.0	v3.x
>=6.0.0 <8.0.0	v2.x
v5.x.x	v1.x

---

Table of contents

• Features
• Getting started
• API
• Change detection
• Custom styles
  • Validation state
• Contributing
• Development
• Inspiration

Features

• Custom binding to property or object
• Custom option, label, header and footer templates
• Virtual Scroll support with large data sets (>5000 items).
• Infinite scroll
• Keyboard navigation
• Multiselect
• Flexible autocomplete with client/server filtering
• Custom search
• Custom tags
• Append to
• Group items
• Output events
• Accessibility
• Good base functionality test coverage
• Themes

Warning

Library is under active development and may have API breaking changes for subsequent major versions after 1.0.0.

Getting started

Step 1: Install ng-select:

NPM

npm install --save @ng-select/ng-select

YARN

yarn add @ng-select/ng-select

Step 2: Import the NgSelectModule and angular FormsModule module:

import { NgSelectModule } from '@ng-select/ng-select';
import { FormsModule } from '@angular/forms';

@NgModule({
  declarations: [AppComponent],
  imports: [NgSelectModule, FormsModule],
  bootstrap: [AppComponent]
})
export class AppModule {}

Step 3: Include a theme:

To allow customization and theming, ng-select bundle includes only generic styles that are necessary for correct layout and positioning. To get full look of the control, include one of the themes in your application. If you're using the Angular CLI, you can add this to your styles.scss or include it in .angular-cli.json (Angular v5 and below) or angular.json (Angular v6 onwards).

@import "~@ng-select/ng-select/themes/default.theme.css";
// ... or 
@import "~@ng-select/ng-select/themes/material.theme.css";

Step 4 (Optional): Configuration

You can also set global configuration and localization messages by injecting NgSelectConfig service, typically in your root component, and customize the values of its properties in order to provide default values.

  constructor(private config: NgSelectConfig) {
      this.config.notFoundText = 'Custom not found';
      this.config.appendTo = 'body';
      // set the bindValue to global config when you use the same 
      // bindValue in most of the place. 
      // You can also override bindValue for the specified template 
      // by defining `bindValue` as property
      // Eg : <ng-select bindValue="some-new-value"></ng-select>
      this.config.bindValue = 'value';
  }

Usage

Define options in your consuming component:

@Component({...})
export class ExampleComponent {

    selectedCar: number;

    cars = [
        { id: 1, name: 'Volvo' },
        { id: 2, name: 'Saab' },
        { id: 3, name: 'Opel' },
        { id: 4, name: 'Audi' },
    ];
}

In template use ng-select component with your options

<!--Using ng-option and for loop-->
<ng-select [(ngModel)]="selectedCar">
   <ng-option *ngFor="let car of cars" [value]="car.id">{{car.name}}</ng-option>
</ng-select>

<!--Using items input-->
<ng-select [items]="cars" 
           bindLabel="name" 
           bindValue="id" 
           [(ngModel)]="selectedCar">
</ng-select>

For more detailed examples see Demo page

SystemJS

If you are using SystemJS, you should also adjust your configuration to point to the UMD bundle.

In your systemjs config file, map needs to tell the System loader where to look for ng-select:

map: {
  '@ng-select/ng-select': 'node_modules/@ng-select/ng-select/bundles/ng-select.umd.js',
}

API

Inputs

Input	Type	Default	Required	Description
[addTag]	boolean | ((term: string) => any | Promise<any>)	false	no	Allows to create custom options.
addTagText	string	Add item	no	Set custom text when using tagging
appearance	string	underline	no	Allows to select dropdown appearance. Set to outline to add border instead of underline (applies only to Material theme)
appendTo	string	null	no	Append dropdown to body or any other element using css selector. For correct positioning body should have position:relative
bindValue	string	-	no	Object property to use for selected model. By default binds to whole object.
bindLabel	string	label	no	Object property to use for label. Default label
[closeOnSelect]	boolean	true	no	Whether to close the menu when a value is selected
clearAllText	string	Clear all	no	Set custom text for clear all icon title
[clearable]	boolean	true	no	Allow to clear selected value. Default true
[clearOnBackspace]	boolean	true	no	Clear selected values one by one when clicking backspace. Default true
[compareWith]	(a: any, b: any) => boolean	(a, b) => a === b	no	A function to compare the option values with the selected values. The first argument is a value from an option. The second is a value from the selection(model). A boolean should be returned.
dropdownPosition	bottom | top | auto	auto	no	Set the dropdown position on open
[groupBy]	string | Function	null	no	Allow to group items by key or function expression
[groupValue]	(groupKey: string, cildren: any[]) => Object	-	no	Function expression to provide group value
[selectableGroup]	boolean	false	no	Allow to select group when groupBy is used
[selectableGroupAsModel]	boolean	true	no	Indicates whether to select all children or group itself
[items]	Array<any>	[]	yes	Items array
[loading]	boolean	-	no	You can set the loading state from the outside (e.g. async items loading)
loadingText	string	Loading...	no	Set custom text when for loading items
labelForId	string	-	no	Id to associate control with label.
[markFirst]	boolean	true	no	Marks first item as focused when opening/filtering.
[isOpen]	boolean	-	no	Allows manual control of dropdown opening and closing. True - won't close. False - won't open.
maxSelectedItems	number	none	no	When multiple = true, allows to set a limit number of selection.
[hideSelected]	boolean	false	no	Allows to hide selected items.
[multiple]	boolean	false	no	Allows to select multiple items.
notFoundText	string	No items found	no	Set custom text when filter returns empty result
placeholder	string	-	no	Placeholder text.
[searchable]	boolean	true	no	Allow to search for value. Default true
[readonly]	boolean	false	no	Set ng-select as readonly. Mostly used with reactive forms.
[searchFn]	(term: string, item: any) => boolean	null	no	Allow to filter by custom search function
[searchWhileComposing]	boolean	true	no	Whether items should be filtered while composition started
[trackByFn]	(item: any) => any	null	no	Provide custom trackBy function
[clearSearchOnAdd]	boolean	true	no	Clears search input when item is selected. Default true. Default false when closeOnSelect is false
[editableSearchTerm]	boolean	false	no	Allow to edit search query if option selected. Default false. Works only if multiple is false.
[selectOnTab]	boolean	false	no	Select marked dropdown item using tab. Default false
[openOnEnter]	boolean	true	no	Open dropdown using enter. Default true
[typeahead]	Subject	-	no	Custom autocomplete or advanced filter.
[minTermLength]	number	0	no	Minimum term length to start a search. Should be used with typeahead
typeToSearchText	string	Type to search	no	Set custom text when using Typeahead
[virtualScroll]	boolean	false	no	Enable virtual scroll for better performance when rendering a lot of data
[inputAttrs]	{ [key: string]: string }	-	no	Pass custom attributes to underlying input element
[tabIndex]	number	-	no	Set tabindex on ng-select
[keyDownFn]	($event: KeyboardEvent) => bool	true	no	Provide custom keyDown function. Executed before default handler. Return false to suppress execution of default key down handlers

Outputs

Output	Description
(add)	Fired when item is added while [multiple]="true". Outputs added item
(blur)	Fired on select blur
(change)	Fired on model change. Outputs whole model
(close)	Fired on select dropdown close
(clear)	Fired on clear icon click
(focus)	Fired on select focus
(search)	Fired while typing search term. Outputs search term with filtered items
(open)	Fired on select dropdown open
(remove)	Fired when item is removed while [multiple]="true"
(scroll)	Fired when scrolled. Provides the start and end index of the currently available items. Can be used for loading more items in chunks before the user has scrolled all the way to the bottom of the list.
(scrollToEnd)	Fired when scrolled to the end of items. Can be used for loading more items in chunks.

Methods

Name	Description
open	Opens the select dropdown panel
close	Closes the select dropdown panel
focus	Focuses the select element
blur	Blurs the select element

Other

Name	Type	Description
[ngOptionHighlight]	directive	Highlights search term in option. Accepts search term. Should be used on option element. README
NgSelectConfig	configuration	Configuration provider for the NgSelect component. You can inject this service and provide application wide configuration.
SELECTION_MODEL_FACTORY	service	DI token for SelectionModel implementation. You can provide custom implementation changing selection behaviour.

Custom selection logic

Ng-select allows to provide custom selection implementation using SELECTION_MODEL_FACTORY. To override default logic provide your factory method in your angular module.

// app.module.ts
providers: [
    { provide: SELECTION_MODEL_FACTORY, useValue: <SelectionModelFactory>CustomSelectionFactory }
]

// selection-model.ts
export function CustomSelectionFactory() {
    return new CustomSelectionModel();
}

export class CustomSelectionModel implements SelectionModel {
    ...
}

Change Detection

Ng-select component implements OnPush change detection which means the dirty checking checks for immutable data types. That means if you do object mutations like:

this.items.push({id: 1, name: 'New item'})

Component will not detect a change. Instead you need to do:

this.items = [...this.items, {id: 1, name: 'New item'}];

This will cause the component to detect the change and update. Some might have concerns that this is a pricey operation, however, it is much more performant than running ngDoCheck and constantly diffing the array.

Custom styles

If you are not happy with default styles you can easily override them with increased selector specificity or creating your own theme. This applies if you are using no ViewEncapsulation or adding styles to global stylesheet. E.g.

<ng-select class="custom"></ng-select>

.ng-select.custom {
    border:0px;
    min-height: 0px;
    border-radius: 0;
}
.ng-select.custom .ng-select-container  {            
    min-height: 0px;
    border-radius: 0;
}

If you are using ViewEncapsulation, you could use special ::ng-deep selector which will prevent scoping for nested selectors altough this is more of a workaround and we recommend using solution described above.

.ng-select.custom ::ng-deep .ng-select-container  {            
    min-height: 0px;
    border-radius: 0;
}

WARNING: Keep in mind that ng-deep is deprecated and there is no alternative to it yet. See Here.

Validation state

By default when you use reactive forms validators or template driven forms validators css class ng-invalid will be applied on ng-select. You can show errors state by adding custom css style

ng-select.ng-invalid.ng-touched .ng-select-container {
    border-color: #dc3545;
    box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075), 0 0 0 3px #fde6e8;
}

Contributing

Contributions are welcome. You can start by looking at issues with label Help wanted or creating new Issue with proposal or bug report. Note that we are using https://conventionalcommits.org/ commits format.

Development

Perform the clone-to-launch steps with these terminal commands.

Run demo page in watch mode

git clone https://github.com/ng-select/ng-select
cd ng-select
yarn
yarn run start

Testing

yarn run test
or
yarn run test:watch

Release

To release to npm just run ./release.sh, of course if you have permissions ;)

Inspiration

This component is inspired by React select and Virtual scroll. Check theirs amazing work and components :)