Angular way to stop negative values from being entered in input type number (on copy-paste & increase, decrease) also

Question

my requirement is in an angular project i'm taking number input in a form like this

<input type="number" #input class="form-control" [(ngModel)]="dataItem.quantity"

i should not allow user to enter negative values even from copy-paste or through increase / decrease button of input type number or thought keyboard.

how can we acheive this, i have seen some directives, there they are taking input as 'text', my case is it should be "input type number" only.

It should allow decimals also.

Please Help me.

Answer 1

You can do like below

HTML:

<input type="number" min="0" (input)="checkValue($event)">

TS:

checkValue(event) {
  if (event.target.value < 0) {
    event.target.value = 0;
  }
}

You can use (keyup) too

Update:

In the Angular way, you can create a pipe. Working stackblitz

In the HTML:

<input type="number" min="0" [ngModel]="testValue | nonegativevalue" (ngModelChange)="testValue=$event">

nonegativevaluepipe

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({name: 'nonegativevalue'})
export class NoNegativeValue implements PipeTransform {
  transform(value: number): number {
    if(value < 0) {
      value = 0;
      return value;
    }
    return value;
  }
}

If you use reactive form, then check this stackblitz

Answer 2

Try this..

<input type="number" min="0" #input class="form-control" [(ngModel)]="dataItem.quantity" 
oninput="this.value = this.value.replace(/[^0-9.]/g, '').replace(/(\..*)\./g, '$1');">