signup3.html

<ion-header>
    <ion-navbar>
        <ion-title>Registrarse</ion-title>
    </ion-navbar>
</ion-header>

<ion-content>
    <form #signUpForm="ngForm" (submit)="signUp()">
        <ion-list>
            <ion-item>
                <ion-label stacked>Correo electrónico</ion-label>
                <ion-input [(ngModel)]="userModel.email" type="email" autocorrect="off" autocapitalize="none" name="email" pattern="[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,3}$"
                    required></ion-input>
            </ion-item>

            <ion-item>
                <ion-label stacked>Contraseña</ion-label>
                <ion-input [(ngModel)]="userModel.password" type="password" name="password" required minlength="6"></ion-input>
            </ion-item>

            <div padding-left padding-right padding-top>
                <button ion-button [disabled]="!signUpForm.form.valid" block>Registrarse</button>                
            </div>
        </ion-list>
    </form>
    <div padding>
        <div padding-bottom>Entrar con una red social:</div>
        <button ion-button block (click)="signInWithFacebook()" class="facebook-btn">Entrar con Facebook</button>
    </div>
</ion-content>