Angular Multiselect Dropdown for Bootstrap CSS

Compiled for Angular 15 with Ivy enabled. If you are using an older version of Angular and are relying on the View Engine, you can use version 2.1 of this library.

Customizable multiselect dropdown in Angular(9+), TypeScript with Bootstrap css.

Dependencies

• Bootstrap CSS 3 or 4
• Font Awesome (optional)

Install

• Install with npm: npm install ngx-bootstrap-multiselect --save.

Usage

Import NgxBootstrapMultiselectModule into your @NgModule.

import { NgxBootstrapMultiselectModule } from 'ngx-bootstrap-multiselect';

@NgModule({
  // ...
  imports: [
    NgxBootstrapMultiselectModule,
  ]
  // ...
})

Define options in your consuming component:

import { IMultiSelectOption } from 'ngx-bootstrap-multiselect';

export class MyClass implements OnInit {
    optionsModel: number[];
    myOptions: IMultiSelectOption[];

    ngOnInit() {
        this.myOptions = [
            { id: 1, name: 'Option 1' },
            { id: 2, name: 'Option 2' },
        ];
    }
    onChange() {
        console.log(this.optionsModel);
    }
}

In your template, use the component directive:

<ngx-bootstrap-multiselect [options]="myOptions" [(ngModel)]="optionsModel" (ngModelChange)="onChange()"></ngx-bootstrap-multiselect>

Customize

Import the IMultiSelectOption and IMultiSelectTexts interfaces to enable/override settings and text strings:

// Default selection
optionsModel: number[] = [1, 2];

// Settings configuration
mySettings: IMultiSelectSettings = {
    enableSearch: true,
    checkedStyle: 'fontawesome',
    buttonClasses: 'btn btn-default btn-block',
    dynamicTitleMaxItems: 3,
    displayAllSelectedText: true
};

// Text configuration
myTexts: IMultiSelectTexts = {
    checkAll: 'Select all',
    uncheckAll: 'Unselect all',
    checked: 'item selected',
    checkedPlural: 'items selected',
    searchPlaceholder: 'Find',
    searchEmptyResult: 'Nothing found...',
    searchNoRenderText: 'Type in search box to see results...',
    defaultTitle: 'Select',
    allSelected: 'All selected',
};

// Labels / Parents
myOptions: IMultiSelectOption[] = [
    { id: 1, name: 'Car brands', isLabel: true },
    { id: 2, name: 'Volvo', parentId: 1 },
    { id: 3, name: 'Honda', parentId: 1 },
    { id: 4, name: 'BMW', parentId: 1 },
    { id: 5, name: 'Colors', isLabel: true },
    { id: 6, name: 'Blue', parentId: 5 },
    { id: 7, name: 'Red', parentId: 5 },
    { id: 8, name: 'White', parentId: 5 }
];

<ngx-bootstrap-multiselect [options]="myOptions" [texts]="myTexts" [settings]="mySettings" [(ngModel)]="optionsModel"></ngx-bootstrap-multiselect>

Settings

Texts

Other examples

Single select

Although this dropdown is designed for multiple selections, a common request is to only allow a single selection without requiring the user to unselect their previous selection each time. This can be accomplished by setting selectionLimit to 1 and autoUnselect to true.

{
  ...
  selectionLimit: 1,
  autoUnselect: true,
  ...
}

Lazy Loading

This Stackblitz link demonstrates an implementation of lazy loading: Lazy loading Stackblitz

If using search during lazy load, the search term must be supplied to the back end to return the appropriate number of results. Standard inline search will not work, since the front end does not know how many items to load to retrieve the desired number of matches.

If selectAddedValues is set to true for lazy loading, all values loaded to the checklist are checked when matching Select All criteria. If a search is used with Select All, each search is added to a collection to be matched against when scrolling in. If selectAddedValues is false, only presently viewed matches will check on Select All.

If a user searches countries on al and clicks Select All, all matches will be selected as they load in on scrolling. If the user clears the search box, only matches to al will select upon scrolling in all country values.

If the user then searches an and clicks Select All, all matches to an and al will select upon scrolling in. If the user then clicks Unselect All while an is the search criteria, all matches to an will clear, except those that match al, which is still stored.

Clicking Select All or Unselect All with no search criteria present will clear all previously stored searches. Any search match that is manually unchecked will remain unchecked unless matched by a new search Select All.

The implementor will be responsible for completing checks when the form is submitted. This could possibly either consist of completing the load of all lazy load checklists before submitting or sending checked items and search criteria to a back-end api to complete.

Use model driven forms with ReactiveFormsModule:

import { IMultiSelectOption } from 'ngx-bootstrap-multiselect';

export class MyClass implements OnInit {
    myOptions: IMultiSelectOption[] = [
        { id: 1, name: 'Option 1' },
        { id: 2, name: 'Option 2' },
    ];

    ngOnInit() {
        this.myForm = this.formBuilder.group({
            optionsModel: [1, 2], // Default model
        });

        this.myForm.controls['optionsModel'].valueChanges
            .subscribe((selectedOptions) => {
                // changes
            });
    }
}

<form [formGroup]="myForm">
    <ngx-bootstrap-multiselect [options]="myOptions" formControlName="optionsModel"></ngx-bootstrap-multiselect>
</form>

Developing

Pull requests are welcome!

License

[MIT]