Upgrading to Angular 2 - Reactive Forms (RC3 New Forms)

by Guido Tapia

in software-engineering,

June 30, 2016

Upgrading to new the new form engine in Angular 2 (RC3) is fairly straight forward and not nearly as dawnting as some of the router changes in the past. So here is my quick and dirty how to which worked on my projects (no other guarantee).

Firstly - Read the docs One of the issues with working in this beta/RC arena is that the documentation of these things is quite hard to find. The best doc I found about this is here: https://docs.google.com/document/u/1/d/1RIezQqE4aEhBRmArIAS1mRIZtWFf6JxN_7B4meyWK0Y/pub Read that, it basically has all you need towards the bottom.

npm packages.json When you upgrade to RC3 you will need to run:

npm install --save @angular/forms

This will install your latest form.

Gulp Update your gulp script and ensure the new forms files are copied to your testing directory.

System.js Update your system JS to include this new forms folder. Since System.js can be configured a million ways I will just show what I added to my config:

packages: {
'@angular/forms' : {defaultExtension: 'js', main: 'index.js'}
map : {
 '@angular/forms' : 'lib/@angular/forms'

Bootstrapper In your boot.ts or app.ts add the following:

import {disableDeprecatedForms, provideForms} from '@angular/forms';
bootstrap(AppComponent, [ ... disableDeprecatedForms(), provideForms() ]);

Templates: Search and replace your templates for the following:

ngFormModel -> formGroup
ngSwitchWhen -> ngSwitchCase (not really new forms but RC3 so do it anyway)
ngFormControl -> formControl

That’s all I had to do, but according to “the doc” you should also do the following (note, I did not test these):

formControlName (deprecated: ngControl)
formGroupName (deprecated: ngControlGroup)
formArrayName (deprecated: ngControlGroup)


Components In your components remove all the old form related imports, these would be coming from @angular/common probably. The ones I removed are:

Control, ControlGroup, FormBuilder, Validators

And then replace with the new directives/components from @angular/forms. The new names are:

FormControl() (deprecated: Control)
FormGroup() (deprecated: ControlGroup)
FormArray() (deprecated: ControlArray)
FormBuilder (same)
Validators (same)

All directives are included in the single REACTIVE_FORM_DIRECTIVES so just add this to your @Component.directives array. Then remember to search and replace component your code for the following.

ControlGroup -> FormGroup
ControlArray -> FormArray
Control -> FormControl

Conclusion Very straight forward once you find “the doc” (the magical doc).