Angular Trim on Blur Directive

The directive helps to trim whitespaces of an input text value on blur.

It lies on a simple fact that Angular listens to input event to bring the view-to-model binding into being.

* According to the description of updateOn property of AbstractControlOptions interface, when updateOn is set to blur or submit, Angular listens to blur or submit event for model update. In this directive, update-on-blur case is handled in a hack way. No further processing is required for update-on-submit case.

Since extra input and blur events are dispatched, if you bind a callback to input event or blur event, the callback will be invoked twice on input or blur.

To overcome the disadvantage, a debounced function is recommended for the event binding.

The compiled package is tested with Angular 5 and 6. To use it in Angular 4, you may import the .ts file directly (see Usage). For Angular 2, you may try it in Angular 4’s way, but it’s not tested.

Usage

1.Install ng2-trim-on-blur.

    npm i -S ng2-trim-on-blur

2.Import TrimOnBlurModule to your Angular module.

Angular 4

import { TrimOnBlurModule } from 'ng2-trim-on-blur/src';
@NgModule({
  imports: [
    ...
    TrimOnBlurModule,
    ...
  ],
  ...

Angular 5+

import { TrimOnBlurModule } from 'ng2-trim-on-blur';
@NgModule({
  imports: [
    ...
    TrimOnBlurModule,
    ...
  ],
  ...

3.Add the “trimOnBlur” attribute to an input element.

     <input type="text" ... trimOnBlur>

4.Want to trim the value on input? Try ngx-trim-directive.

Good luck.