ngx-select-dropdown

ngx-select-dropdown Custom Dropdown component for Angular 4+ with multiple and single selection options

Features

• single select dropdown
• multi select dropdown
• search dropdown list
• arrows keys support
• limit number of items displayed in dropdown
• custom sort
• angular forms support
• angular v4 and above supported
• cross browser support

Examples

• demo-page

Installation

• npm install ngx-select-dropdown

Using with webpack and tsc builds/ angular-cli builds

• import SelectDropDownModule into your app.module;

import { SelectDropDownModule } from 'ngx-select-dropdown'

• add SelectDropDownModule to the imports of your NgModule:

@NgModule({
  imports: [
    ...,
    SelectDropDownModule
  ],
  ...
})
class YourModule { ... }

• include css styles in you angular-cli.json for versions earlier than 1.4.0

 "styles": [
        "../node_modules/ngx-select-dropdown/dist/assets/style.css"
      ],

• use <ngx-select-dropdown></ngx-select-dropdown> in your templates to add the custom dropdown in your view like below

<ngx-select-dropdown [instanceId]="'instance1'" (change)="selectionChanged($event)" [multiple]="true" [(ngModel)]="dataModel" [config]="config" [options]="dropdownOptions"></ngx-select-dropdown>

• use with reactive form like

<ngx-select-dropdown [instanceId]="'instance2'"  (change)="selectionChanged($event)" formControlName="selectData" [multiple]="true" [config]="config" [options]="dropdownOptions"></ngx-select-dropdown>

Config

Input

• multiple: boolean - true/false beased if multiple selection required or not Defaults to false.
• options: Array - Array of string/objects that are to be the dropdown options.
• disabled: boolean - disabled attribute to disable the dropdown when required.
• config: Object - configuration object.
• instanceId: any - instanceId of the dropdwon component instance.

config = {
        displayFn:(item: any) => { return item.hello.world; } //to support flexible text displaying for each item
        displayKey:"description", //if objects array passed which key to be displayed defaults to description
        search:true //true/false for the search functionlity defaults to false,
        height: 'auto' //height of the list so that if there are more no of items it can show a scroll defaults to auto. With auto height scroll will never appear
        placeholder:'Select' // text to be displayed when no item is selected defaults to Select,
        customComparator: ()=>{} // a custom function using which user wants to sort the items. default is undefined and Array.sort() will be used in that case,
        limitTo: 0 // number thats limits the no of options displayed in the UI (if zero, options will not be limited)
        moreText: 'more' // text to be displayed whenmore than one items are selected like Option 1 + 5 more
        noResultsFound: 'No results found!' // text to be displayed when no items are found while searching
        searchPlaceholder:'Search' // label thats displayed in search input,
        searchOnKey: 'name' // key on which search should be performed this will be selective search. if undefined this will be extensive search on all keys
        clearOnSelection: false // clears search criteria when an option is selected if set to true, default is false
        inputDirection: 'ltr' // the direction of the search input can be rtl or ltr(default)
      }

Output

• change: Event - change event when user changes the selected options
• open: Event - open event when the dropdown toogles on
• close: Event - close event when the dropdown toogles off
• searchChange: Event - search change event when the search text changes

Dropdown service (Injectable)

• openDropdown(instanceId:string) - method to open a particular dropdown instance
• closeDropdown(instanceId:string) - method to close a particular dropdown instance
• isOpen(instanceId:string) - method to check if a particular instance dropdown is open
• openInstances: string[] - instanceId list of all the open instances

Change detection

As of now ngx-select-dropdown uses Default change detection startegy which means dirty checking checks for immutable data types. And in Javascript Objects and arrays are mutable. So when changing any of the @Input parameters if you mutate an object change detection will not detect it. For ex:-

this.options.push({id: 34, description: 'Adding new item'});

// or

config.height = '200px';

Both the above scenarios will not trigger the change detection. In order for the componet to detect the changes what you need to do is:-

this.options = [...this.options, {id: 34, description: 'Adding new item'}];

// or

config = {...config, height:'200px'};

Changelog

• v0.1.0

 Added a change event so that user can attach a change event handler.
 If multiselect the selected text will display first item and + count for eg. (Option 1 + 2 more) .

• v0.2.0

 Angular 4 and above support.
 Bug with search functionality fixed.

• v0.3.0

 Support for Observable data source for options and async pipe.
 IE bug with styling.
 Few other minor bug fixes.

• v0.4.0

 Use arrows keys and enter to select items from available options.
 Case insensitive search.
 Few other minor bug fixes.

• v0.5.0

 Support for scroll bar with too many list items.
 Few other minor bug fixes.

• v0.7.0

 Support for limito pipe to limit number of options displayed in case of too many options.
 Support for customComparator / custom sort function
 Few other minor bug fixes.

• v0.7.2

 Support for angular 6
 Removed dependency on rxjs

• v0.8.0

 No Results found indicator with custom text passed with config
 Custom text for *more* when more than 1 items selected
 Open event emitted
 Close event emitted
 Search placeholder text

• v1.0.0

 Search on a specified key value.
 Support for Reactive forms
 Few other minor imoprovements and fixes

• v1.2.0

 Search text change event searchChange

• v1.3.0

 Clear search on selection config
 Disable with reactive forms .disable()

• v1.5.0

Custom function for displaying text for each option
Add disabled class to different items based on item.disabled

• v2.0.0

Angular library approach opted for development
Angular Ivy compatibility

• v3.0.0

Dropdown singleton service to interact with dropdown instances
Instance identifier
Upgraded to Angular v14 

• v3.0.1

Auto drop based on the screen position
Over-ride css styles for available and selected items using class names `selected-item(s)` and `available-item(s)`

Help Improve

Found a bug or an issue with this? Open a new issue here on GitHub.

Contributing to this project

Anyone and everyone is welcome to contribute. Please take a moment to review the guidelines for contributing.

• Bug reports
• Feature requests
• Pull requests