ng2-tag-input

Angular2 Tag Input

This is a component for Angular 2. Design and API are blandly inspired by Angular Material's md-chips.

Demo

Check out the live demo (with source code) here http://www.webpackbin.com/VkEgHA8xM. [OUTDATED]

Quick start. Install the component from NPM by running:

npm install ng2-tag-input --save

Please notice that the latest version on NPM may not reflect the branch master. Send me an email or open an issue and tag me if you need it to be published.

If you want to run the tests, run the command:

npm test

Set up the module

The component is updated to use the latest version of Angular 2. This means it requires some configuration to correctly work with your app. Ensure, you are registering the following providers when bootstrapping the app:

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { FormsModule } from '@angular/forms';
import { App } from './home/home';

import { NgModule }       from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';

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

platformBrowserDynamic().bootstrapModule(AppModule);

Please do have a look at the file demo/app.ts if you are unsure how to configure the app.

Configuration

Ensure you import the module:

import { TagInputModule } from 'ng2-tag-input';

// please notice this is the new way of telling a Component
// to import another component...no more directives[]
@NgModule({
   imports: [TagInputModule]
})
export class MyModule {}

Configuration for SystemJS

Many users have reported issues with SystemJS. I got it working with the following additions to the SystemJS configuration:

// packages object
{
        'ng2-tag-input': {
            main: 'dist/ng2-tag-input.bundle.js',
            format: 'cjs',
        },
        'ng2-material-dropdown': {
            defaultExtension: 'js',
            main: 'dist/ng2-dropdown.bundle.js',
            format: 'cjs',
        },
        'ng2-tag-input/modules/components/tag-input.template.html': {
            defaultJSExtension: false
        }
        // rest of the configuration
};

API for TagInputComponent

Inputs

Model

• ngModel - [string[] | TagModel[]] - Model of the component. Accepts an array of strings as input OR an array of objects.

If you do use an array of objects, make sure you:

• define two properties, value and display. Value will uniquely identify the items, display will be the value displayed.
• or, in alternative, provide the keys using the inputs identifyBy and displayBy

Properties

• placeholder - [?string] - String that sets the placeholder of the input for entering new terms.
• secondaryPlaceholder - [?string] - String that sets the placeholder of the input for entering new terms when there are 0 items entered.
• maxItems - [?number] - Sets the maximum number of items it is possible to enter.
• readonly - [?boolean] - Sets the tag input static, not allowing deletion/addition of the items entered.
• separatorKeys - [?number[]] - Array of keyboard keys with which is possible to define the key for separating terms. By default, only Enter is the defined key.
• transform - [?(item: string) => string] - a function that takes as argument the value of an item, and returns a string with the new value when appended. If the method returns null/undefined/false, the item gets rejected.
• inputId - [?string] - custom ID assigned to the input
• inputClass - [?string] - custom class assigned to the input
• clearOnBlur - [?boolean] - if set to true, it will clear the form's text on blur events
• hideForm - [?number] - if set to true, will remove the form from the component
• onTextChangeDebounce - [?number] - number of ms for debouncing the onTextChange event

Validation

• validators - [?Validators[]] - an array of Validators (custom or Angular's) that will validate the tag before adding it to the list of items. It is possible to use multiple validators.
• errorMessages - [?Object{error: message}] - an object whose key is the name of the error (ex. required) and the value is the message you want to display to your users

Autocomplete

• autocompleteItems - [?string[]] - an array of items to populate the autocomplete dropdown
• onlyFromAutocomplete - [?boolean] - if true, it will be possible to add new items only from the autocomplete dropdown
• showDropdownIfEmpty - [?boolean] - if true, the dropdown of the autocomplete will be shown as soon as the user focuses on the form

Tags as Objects

• identifyBy - [?any] - any value you want your tag object to be defined by
• displayBy - [?string] - the string displayed in a tag object

Outputs

• onAdd - [?onAdd($event: string)] - event fired when an item has been added
• onRemove - [?onRemove($event: string)] - event fired when an item has been removed
• onSelect - [?onSelect($event: string)] - event fired when an item has been selected
• onFocus - [?onFocus($event: string)] - event fired when the input is focused - will return current input value
• onBlur - [?onBlur($event: string)] - event fired when the input is blurred - will return current input value
• onTextChange - [?onTextChange($event: string)] - event fired when the input value changes

API for TagInputDropdownComponent

TagInputDropdownComponent is a proxy between ng2-tag-input and ng2-material-dropdown.

• offset - [?string] - offset to adjust the position of the dropdown with absolute values

More options to customise the dropdown will follow.

Basic Example

Component

@Component({
    selector: 'app',
    template: `<tag-input [(ngModel)]='items'></tag-input>`
});
export class App {
    items = ['Pizza', 'Pasta', 'Parmesan'];
    options = {
        placeholder: "+ term",
        secondaryPlaceholder: "Enter a new term",
        separatorKeys: [4, 5]
        maxItems: 10
    }
    onItemAdded(item) {
        console.log(``${item} has been added`)
    }
    onItemRemoved(item) {
        console.log(``${item} has been removed :(`)
    }
    // ...
}

<tag-input [(ngModel)]='items'
           [placeholder]="options.placeholder"
           [secondaryPlaceholder]="options.secondaryPlaceholder"
           [maxItems]="options.maxItems"
           [separatorKeys]="options.separatorKeys">
</tag-input>

Using an array of objects

// itemsAsObjects = [{value: 0, display: 'Angular'}, {value: 1, display: 'React'}];
<tag-input [ngModel]="itemsAsObjects"></tag-input>

Using an array of with custom identifyBy and displayBy

// itemsAsObjects = [{id: 0, name: 'Angular'}, {id: 1, name: 'React'}];
<tag-input [ngModel]="itemsAsObjects" [identifyBy]="'id'" [displayBy]="'name'"></tag-input>

Max number of items

<tag-input [(ngModel)]='items' [maxItems]='5'></tag-input>

Autocomplete

<tag-input [ngModel]="['@item']"
           [autocompleteItems]="['Item1', 'item2', 'item3']">
       <tag-input-dropdown></tag-input-dropdown>
</tag-input>

This will accept items only from the autocomplete dropdown:

<tag-input [ngModel]="['@item']"
           [onlyFromAutocomplete]="true"
           [showDropdownIfEmpty]="true"
           [autocompleteItems]="['iTem1', 'item2', 'item3']">
    <tag-input-dropdown></tag-input-dropdown>
</tag-input>

Define a template for your menu items

<tag-input [ngModel]="['@item']"
           [onlyFromAutocomplete]="true"
           [showDropdownIfEmpty]="true"
           [autocompleteItems]="['iTem1', 'item2', 'item3']">
    <tag-input-dropdown>
        <template let-item="item" let-index="index">
            {{ index }}: {{ item }}
        </template>
    </tag-input-dropdown>
</tag-input>

Additional keys to separate tags

If you want to use more keys to separate items, add them to separatorKeys as an array of keyboard key codes.

<tag-input [(ngModel)]='items' separatorKeys="[32]"></tag-input>

Validation

Create some validation methods in your component:

class MyComponent {
    private startsWithAt(control: FormControl) {
        if (control.value.charAt(0) !== '@') {
            return {
                'startsWithAt@': true
            };
        }

        return null;
    }
    
    private endsWith$(control: FormControl) {
        if (control.value.charAt(control.value.length - 1) !== '$') {
            return {
                'endsWith$': true
            };
        }

        return null;
    }
    
    public validators = [this.startsWithAt, this.endsWith$];
    
    public errorMessages = {
        'startsWithAt@': 'Your items need to start with "@"',
        'endsWith$': 'Your items need to end with "$"'
    };
}

Pass them to the tag-input component:

<tag-input [ngModel]="['@item']"
           [errorMessages]="errorMessages"
           [validators]="validators">
</tag-input>

Items Transformer

Set up a transformer, which is a function that takes the item's string as parameter, and should return the transformed string.

class MyComponent {
    public transformer(item: string): string {
        return `@${item}`;
    }
    // ...
}

Every item entered will be prefixed with @.

<tag-input [ngModel]="['@item']" [transform]="transformer"></tag-input>

Events

Set up some methods that will run when its relative event is fired.

<tag-input [(ngModel)]='items'
           (onBlur)="onInputBlurred($event)"
           (onFocus)="onInputFocused($event)"
           (onSelect)="onSelected($event)"
           (onRemove)="onItemRemoved($event)"
           (onTextChange)="onTextChange($event)"
           (onAdd)="onItemAdded($event)">
</tag-input>

Readonly

If readonly is passed to the tag-input, it won't be possible to select, add and remove items.

<tag-input [ngModel]="['Javascript', 'Typescript']" [readonly]="true"></tag-input>

Custom items template

Define your own template, but remember to set up the needed events using the input reference.

<tag-input [ngModel]="['@item']" #input>
    <template let-item="item"> <!-- DEFINE HERE YOUR TEMPLATE -->
        <span>
            <!-- YOU MAY ACTUALLY DISPLAY WHATEVER YOU WANT IF YOU PASS AN OBJECT AS ITEM -->
            item: {{ item.display }}
        </span>
        <span (click)="input.removeItem(item)" class="ng2-tag__remove-button">
            x
        </span>
    </template>
</tag-input>

Built-in Themes

If you don't like how the default theme looks, or you just need it to fit in a different design, you can choose 2 new themes: dark and minimal.

<tag-input [(ngModel)]='items' theme='minimal'></tag-input>
<tag-input [(ngModel)]='items' theme='dark'></tag-input>

You still don't like them? It's fine, read the next section.

Customization

Thanks to the newly introduced component inheritance, it is possible to finally customize the component with your own settings. It is not super straightforward, but you can finally define your own templates and styles. Let's see how it's done.

The first thing to do, is to define a new component and extend tag-input:

import { Component, forwardRef } from '@angular/core';
import { TagInputComponent } from 'ng2-tag-input';
import { NG_VALUE_ACCESSOR } from '@angular/forms';

// all this boilerplate is needed
@Component({
    selector: 'custom-tag-input', // or whatever you want
    providers: [{
        provide: NG_VALUE_ACCESSOR,
        useExisting: forwardRef(() => CustomComponent),
        multi: true
    }],
    
    // not needed, but you may want it
    styleUrls: [ './custom.scss' ],
    
    // you can add your own, but for now let's go with this
    templateUrl: '{{ node_modules }}/ng2-tag-input/dist/modules/components/tag-input.template.html' 
    // or
    // template: require('ng2-tag-input/dist/modules/components/tag-input.template.html')
})
export class CustomComponent extends TagInputComponent { }

And here is where we define our own styles:

// I'm overwriting the variables
$tag-color: #222;
$tag-border-radius: 100px;
$color-primary-default: #000;
// have a look at https://github.com/Gbuomprisco/ng2-tag-input/tree/master/modules/components/themes
// for having an idea on how to change the variables and how they're defined

@import "~ng2-tag-input/dist/modules/components/tag-input.style.scss";

We now need to register this newly created component. Here is how our app module looks like:

// .. all other imports
import { TagInputModule } from 'ng2-tag-input';
import { CustomComponent } from './custom/custom.component'; // my newly defined component

@NgModule({
    imports: [
        BrowserModule,
        CommonModule,
        FormsModule,

        TagInputModule, // we need this here
    ],
    declarations: [ Home, CustomComponent ], // we need this here
    bootstrap: [ Home ], // this is just an example
    entryComponents: [ Home ] // this is just an example
})
export class AppModule {}
platformBrowserDynamic().bootstrapModule(AppModule);

Use tags without a form

It is possible to use <tag> components independently from the tag-input component. In order to do so, pass to the component the input model (TagModel).

Notice: by default, these are unstyled. You are free to add the required styles yourself. For example, just add a class tag. If you wish to copy the same style as the one used in the component, please have a look at source code.

<div class="flex">
    <tag [model]="{display: 'Tag 1'}" class='tag'></tag>
    <tag [model]="{display: 'Tag 2'}" class='tag'></tag>
    <tag [model]="{display: 'Tag 3'}" [readonly]="true" class='tag'></tag>
</div>