Building reactive forms
Reactive forms, as the name implies, reactively provide access to web forms. They are built with reactivity in mind, where input controls and their values can be manipulated using observable streams. They also maintain an immutable state of form data, making them easier to test because we can be sure that the form state can be modified explicitly and consistently.
Reactive forms have a programmatic approach to creating form elements and setting up validation rules by setting everything up in the component class. The Angular key classes involved in this approach are the following:
FormControl: Represents an individual form control, such as an<input>element.FormGroup: Represents a collection of form controls. The<form>element is the topmostFormGroupin the hierarchy of a reactive form.FormArray: Represents a collection of form controls, just likeFormGroup, but can be modified at runtime. For example, we can add or...
