Angular 5 Reactive Form Pattern Validators

Question

I need to come up with a validation pattern in Reactive Form (Form Control) using Validators.pattern. The conditions are Alphanumeric, Only underscore_, hyphen- are allowed. Any type of space should not be allowed. Is there any one single pattern that will help me achieve this.

Thanks.

Answer 1

Validators.pattern with FormBuilder We can use Validators.pattern for pattern validation while creating form either by FormBuilder or by FormGroup. Here we will provide code snippet for FormBuilder.

unamePattern = "^[a-z0-9_-]{8,15}$";
userForm = this.formBuilder.group({
username: ['', Validators.pattern(this.unamePattern)],}) 

But if you dont want to allow "-" just use this

unamePattern = "^[a-z0-9_]{8,15}$";

Answer 2

Try Validators.pattern(/^[a-zA-Z0-9_-]*$/)