title: How to show error messages in forms in Ionic 3
body: <p>Here i have try to display error messages in <code>forms</code> in <code>Ionic-3</code>.</p>
  
  <p>Here is my <code>email.html</code> file:</p>
  
  <pre><code>&lt;form [formGroup]="form" (submit)="signIn()"&gt;
      &lt;ion-grid&gt;
          &lt;ion-row&gt;
              &lt;ion-col&gt;
                   &lt;ion-item&gt;
                      &lt;ion-label color="primary" floating&gt;Email&lt;/ion-label&gt;
                      &lt;ion-input [formControl]="form.controls['email']"&gt;&lt;/ion-input&gt;
                    &lt;/ion-item&gt;
  
                    &lt;p *ngIf="form.controls.email.errors &amp;&amp; form.controls.email.dirty" class="danger" padding&gt;Email is not valid.&lt;/p&gt;
  
              &lt;/ion-col&gt;
          &lt;/ion-row&gt;
      &lt;/ion-grid&gt;
  
      &lt;ion-list padding&gt;
          &lt;ion-item&gt;
              &lt;button ion-button default item-end color="light" (click)="cancel()"&gt;CANCEL&lt;/button&gt;
              &lt;button ion-button default item-end color="next" [disabled]="!form.valid" (click)="next()"&gt;NEXT&lt;/button&gt;
          &lt;/ion-item&gt;
      &lt;/ion-list&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>In my <code>email.ts</code> file i have:</p>
  
  <pre><code>export class EmailSignupPage {
  
     form : FormGroup;
  
     constructor(
         private formBuilder: FormBuilder,
         public navCtrl: NavController,
         public navParams: NavParams,
     ) {
         this.form = this.formBuilder.group({
          email: ['', Validators.compose([Validators.required, Validators.email])]
         });
     }
  
     ionViewDidLoad() {
  
     }
  
     next() {
         this.navCtrl.push(CredentialPage);
     }
  
     cancel() {
         this.navCtrl.popToRoot();
     }
  }
  </code></pre>
  
  <p>I think my code is fine in <code>email.ts</code> file, but i don't know how to display errors in my form when it validate as i'm new to ionic and angular! </p>
  
  <p>Is there any one who can help me with this?</p>
  
  <p>Thanks!</p>