angular - ngModelChange with input length -

i want set limit on number of integers in input field maxlength when type text. below code in template.

  <ion-input        type="number"        placeholder="username (required)"        [ngmodel]="test"       (ngmodelchange)="getlength($event)"       name="test">    </ion-input> 

in .ts,

  getlength(data){     if(data.length > 8){       console.log(1);       let data1 = data.substring(0,8);       this.test = data1;        return false;     }   } 

any idea how prevent event keypress when length greater 8.

thanks, ashley

use formbuilder perform more complex validation, it'll save lot of time , effort.

import {formbuilder, formgroup} '@angular/forms';  constructor(private fb: formbuilder) {}  public myform: formgroup = this.fb.group({   username: ['', [validators.required, validators.maxlength(8)]] }); 

and use like:

<!-- swap div whatever parent container --> <div>   <ion-input type="number" formcontrolname="username"> </div> 

then check validity of form with:

this.myform.valid 

which evaluate either true or false depending on whether it's valid or not.

edit: add answer above, can use pipe:

import {pipe, pipetransform} '@angular/core';  @pipe({   name: 'maxlength' })  export class maxlength implements pipetransform {    transform(value: string): string {      if (value) {       return value.length > 8 ? value.splice(0, 8) : value;     }   } } 

i haven't tested might have tweak in order work properly. should give rough idea.