Reactive Forms

Angular Framework has Template Driven Forms and Model-Driven Forms (Reactive Forms). Template Driven Forms is HTML centric, whereas Model Driven Forms is typescript centric via the Reactive Forms.

Reactive Forms provides the flexibility of validation, unit testing, and code splitting.

Custom Form Control

When creating custom components, we need to implement ControlValueAccessor and provide it via NG_VALUE_ACCESSOR to communicate with Angular Forms API.

Building Blocks

• FormControl maps to individual HTML input element.
• FromGroup group of individual FormContral instances.
• FormArray is an array of FormControl, FormGroup, or FormArray instances.

Validators

• NG_VALIDATORS — InjectionToken for registering additional synchronous validators used with AbstractControls.

References

• Reactive Forms — Angular.
• Mastering Angular Reactive Forms — BPB Online.
• Angular Forms (Angular Connect 2017) — Kara Erickson — YouTube