Built-in validators

- [Instructor] Angular has support for validation logic…at all of the fundamental building blocks for forms,…formControl, formGroup and formArray.…You can wire up validation for these…by passing in a validator function when you create them.…Angular provides a set of validator functions…as part of the platform…like required, min and max length and pattern.…These functions exist on a class named validators…that is exported from the Angular forms scoped packaged,…just like the rest of the Angular form goodies.…

In the order sheet component TS file,…up in the import statement…for the Angular form scope package,…I can add validators to the list…to make use of some of the built-in ones.…And then down in the buildForm method,…I'm going to add a required validator…onto the customer name formControl.…The formBuilder.control method accepts a validator function…as the second parameter.…So I can set the second argument in the call here…to be validators.required.…

So this formControl is now required to have a value,…but it would be helpful to give the user…