Answer:64

apps/forms/64-form-array/src/app/app.component.ts

@@ -6,68 +6,43 @@ import {
   WritableSignal,
 } from '@angular/core';
 import {
-  AbstractControl,
-  FormArray,
-  FormControl,
-  FormGroup,
-  ReactiveFormsModule,
-  Validators,
-} from '@angular/forms';
-import { ContactFormComponent } from './contact-form.component';
-
-type ContactFormGroup = FormGroup<{
-  firstname: FormControl<string>;
-  lastname: FormControl<string>;
-  relation: FormControl<string>;
-  email: FormControl<string>;
-}>;
-
-type EmailFormGroup = FormGroup<{
-  type: FormControl<string>;
-  email: FormControl<string>;
-}>;
+  applyEach,
+  email,
+  form,
+  FormField,
+  FormRoot,
+  required,
+  SchemaPathTree,
+  validate,
+} from '@angular/forms/signals';
 
-type RegistrationForm = {
-  name: FormControl<string>;
-  pseudo: FormControl<string>;
-  contacts: FormArray<ContactFormGroup>;
-  emails: FormArray<EmailFormGroup>;
-};
-
-type RegistrationValue = {
-  name: string;
-  pseudo: string;
-  contacts: Array<{
-    firstname: string;
-    lastname: string;
-    relation: string;
-    email: string;
-  }>;
-  emails: Array<{
-    type: string;
-    email: string;
-  }>;
-};
+import { ContactFormComponent } from './contact-form.component';
+import { Contact, Email, Registration } from './types';
 
-export const minLengthArray = (min: number) => {
-  return (c: AbstractControl) => {
-    if (c.value.length >= min) return null;
+function ContactSchema(item: SchemaPathTree<Contact>) {
+  required(item.firstName, { message: 'This field is required' });
+  required(item.lastname, { message: 'This field is required' });
+  required(item.relation, { message: 'This field is required' });
+  required(item.email, { message: 'Email is required' });
+  email(item.email, { message: 'Enter a valid email' });
+}
 
-    return { MinLengthArray: true };
-  };
-};
+function EmailSchema(item: SchemaPathTree<Email>) {
+  required(item.type, { message: 'This field is required' });
+  required(item.email, { message: 'Email is required' });
+  email(item.email, { message: 'Enter a valid email' });
+}
 
 @Component({
   selector: 'app-root',
-  imports: [ReactiveFormsModule, JsonPipe, ContactFormComponent],
+  imports: [JsonPipe, ContactFormComponent, FormField, FormRoot],
   changeDetection: ChangeDetectionStrategy.OnPush,
   template: `
     <main class="min-h-screen bg-slate-50 text-slate-900">
       <div class="mx-auto max-w-5xl px-6 py-12">
         <h1 class="mb-6 text-3xl font-semibold">Registration form</h1>
         <form
-          [formGroup]="form"
-          (ngSubmit)="onSubmit()"
+          [formRoot]="registrationForm"
           class="space-y-8 rounded-xl border border-slate-200 bg-white p-6 shadow-sm">
           <section class="space-y-4">
             <h2 class="text-xl font-semibold">Profile</h2>
@@ -78,12 +53,14 @@ export const minLengthArray = (min: number) => {
                 <input
                   class="input"
                   type="text"
-                  formControlName="name"
-                  required
-                  aria-required="true" />
+                  [formField]="registrationForm.name" />
                 <span class="hint">
-                  @if (showError(form.controls.name)) {
-                    This field is required
+                  @if (
+                    registrationForm.name().invalid() &&
+                    (registrationForm.name().touched() ||
+                      registrationForm.name().dirty())
+                  ) {
+                    {{ registrationForm.name().errors()[0].message }}
                   }
                 </span>
               </label>
@@ -93,12 +70,14 @@ export const minLengthArray = (min: number) => {
                 <input
                   class="input"
                   type="text"
-                  formControlName="pseudo"
-                  required
-                  aria-required="true" />
+                  [formField]="registrationForm.pseudo" />
                 <span class="hint">
-                  @if (showError(form.controls.pseudo)) {
-                    This field is required
+                  @if (
+                    registrationForm.pseudo().invalid() &&
+                    (registrationForm.pseudo().touched() ||
+                      registrationForm.pseudo().dirty())
+                  ) {
+                    {{ registrationForm.pseudo().errors()[0]?.message }}
                   }
                 </span>
               </label>
@@ -116,17 +95,23 @@ export const minLengthArray = (min: number) => {
               </button>
             </div>
 
-            <div formArrayName="contacts" class="space-y-4">
-              @for (contact of contacts.controls; track $index) {
+            <div class="space-y-4">
+              @for (contact of registrationForm.contacts; track contact) {
                 <app-contact-form
                   [group]="contact"
                   [index]="$index"
                   (remove)="removeContact($index)"></app-contact-form>
               }
             </div>
 
-            @if (contacts.invalid && (contacts.touched || contacts.dirty)) {
-              <p class="hint">At least one contact is required.</p>
+            @if (
+              registrationForm.contacts().invalid() &&
+              (registrationForm.contacts().touched() ||
+                registrationForm.contacts().dirty())
+            ) {
+              <p class="hint">
+                {{ registrationForm.contacts().errors()[0]?.message }}
+              </p>
             }
           </section>
 
@@ -138,8 +123,8 @@ export const minLengthArray = (min: number) => {
               </button>
             </div>
 
-            <div formArrayName="emails" class="space-y-4">
-              @for (email of emails.controls; track $index) {
+            <div class="space-y-4">
+              @for (emailField of registrationForm.emails; track emailField) {
                 <div
                   class="rounded-lg border border-slate-200 bg-slate-50/40 p-4"
                   data-testid="email-item">
@@ -156,39 +141,44 @@ export const minLengthArray = (min: number) => {
                     </button>
                   </div>
 
-                  <div
-                    class="mt-4 grid gap-4 sm:grid-cols-2"
-                    [formGroupName]="$index">
+                  <div class="mt-4 grid gap-4 sm:grid-cols-2">
                     <label
                       class="flex flex-col gap-1 text-sm font-medium text-slate-700">
                       Type
-                      <select class="input" formControlName="type">
+                      <select class="input" [formField]="emailField.type">
                         <option value="personal">Personal</option>
                         <option value="professional">Professional</option>
                         <option value="other">Other</option>
                       </select>
                       <span class="hint">
-                        @if (showError(email.controls.type)) {
-                          This field is required
+                        @if (
+                          emailField.type().invalid() &&
+                          (emailField.type().touched() ||
+                            emailField.type().dirty())
+                        ) {
+                          {{ emailField.type().errors()[0]?.message }}
                         }
                       </span>
                     </label>
+
                     <label
                       class="flex flex-col gap-1 text-sm font-medium text-slate-700">
                       Email
                       <input
                         class="input"
                         type="email"
-                        formControlName="email"
-                        required
-                        aria-required="true" />
+                        [formField]="emailField.email" />
                       <span class="hint">
-                        @if (showError(email.controls.email)) {
-                          @if (email.controls.email.hasError('required')) {
-                            Email is required
-                          }
-                          @if (email.controls.email.hasError('email')) {
-                            Enter a valid email
+                        @if (
+                          emailField.email().invalid() &&
+                          (emailField.email().touched() ||
+                            emailField.email().dirty())
+                        ) {
+                          @for (
+                            err of emailField.email().errors();
+                            track err.kind
+                          ) {
+                            {{ err.message }}
                           }
                         }
                       </span>
@@ -202,8 +192,12 @@ export const minLengthArray = (min: number) => {
           <div
             class="flex flex-wrap items-center justify-between gap-4 border-t border-slate-200 pt-4">
             <div class="text-sm text-slate-600">
-              <span [class.text-rose-600]="form.invalid">
-                {{ form.invalid ? 'Form incomplete' : 'Ready to submit' }}
+              <span [class.text-rose-600]="registrationForm().invalid()">
+                {{
+                  registrationForm().invalid()
+                    ? 'Form incomplete'
+                    : 'Ready to submit'
+                }}
               </span>
             </div>
             <button type="submit" class="btn-primary">Submit</button>
@@ -246,87 +240,76 @@ export const minLengthArray = (min: number) => {
   ],
 })
 export class AppComponent {
-  readonly contacts = new FormArray<ContactFormGroup>([], {
-    validators: [minLengthArray(1)],
+  readonly formModel = signal<Registration>({
+    name: '',
+    pseudo: '',
+    contacts: [],
+    emails: [],
   });
 
-  readonly emails = new FormArray<EmailFormGroup>([]);
+  readonly registrationForm = form(
+    this.formModel,
+    (schemePath) => {
+      required(schemePath.name, { message: 'This field is required' });
+      required(schemePath.pseudo, { message: 'This field is required' });
 
-  readonly form = new FormGroup<RegistrationForm>({
-    name: new FormControl('', {
-      nonNullable: true,
-      validators: [Validators.required],
-    }),
-    pseudo: new FormControl('', {
-      nonNullable: true,
-      validators: [Validators.required],
-    }),
-    contacts: this.contacts,
-    emails: this.emails,
-  });
+      applyEach(schemePath.contacts, ContactSchema);
+      applyEach(schemePath.emails, EmailSchema);
+
+      validate(schemePath.contacts, ({ value }) => {
+        if (value().length >= 1) return null;
 
-  submittedData: WritableSignal<RegistrationValue | null> = signal(null);
+        return {
+          kind: 'MinLengthArray',
+          message: 'At least one contact is required.',
+        };
+      });
+    },
+    {
+      submission: {
+        action: async () => {
+          return this.submittedData.set(this.formModel());
+        },
+      },
+    },
+  );
+
+  submittedData: WritableSignal<Registration | null> = signal(null);
 
   addContact(): void {
-    this.contacts.push(this.createContactGroup());
+    this.formModel.update((model) => ({
+      ...model,
+      contacts: [
+        ...model.contacts,
+        { firstName: '', lastname: '', relation: '', email: '' },
+      ],
+    }));
   }
 
   removeContact(index: number): void {
-    this.contacts.removeAt(index);
+    this.formModel.update((model) => ({
+      ...model,
+      contacts: [
+        ...model.contacts.slice(0, index),
+        ...model.contacts.slice(index + 1),
+      ],
+    }));
   }
 
   addEmail(): void {
-    this.emails.push(this.createEmailFormGroup());
+    this.formModel.update((model) => ({
+      ...model,
+      emails: [...model.emails, { type: 'personal', email: '' }],
+    }));
   }
 
   removeEmail(index: number): void {
-    this.emails.removeAt(index);
-  }
-
-  onSubmit(): void {
-    this.form.markAllAsTouched();
-    if (this.form.invalid) {
-      return;
-    }
-
-    this.submittedData.set(this.form.getRawValue());
-  }
-
-  showError(control: FormControl<string>): boolean {
-    return control.invalid && (control.touched || control.dirty);
-  }
-
-  private createContactGroup(): ContactFormGroup {
-    return new FormGroup({
-      firstname: new FormControl('', {
-        nonNullable: true,
-        validators: [Validators.required],
-      }),
-      lastname: new FormControl('', {
-        nonNullable: true,
-        validators: [Validators.required],
-      }),
-      relation: new FormControl('', {
-        nonNullable: true,
-        validators: [Validators.required],
-      }),
-      email: new FormControl('', {
-        nonNullable: true,
-        validators: [Validators.required, Validators.email],
-      }),
-    });
-  }
-
-  private createEmailFormGroup(): EmailFormGroup {
-    return new FormGroup({
-      type: new FormControl('personal', {
-        nonNullable: true,
-        validators: [Validators.required],
-      }),
-      email: new FormControl('', {
-        nonNullable: true,
-        validators: [Validators.required, Validators.email],
-      }),
-    });
+    this.formModel.update((model) => ({
+      ...model,
+      emails: [
+        ...model.emails.slice(0, index),
+        ...model.emails.slice(index + 1),
+      ],
+    }));
   }
 }