<form [formGroup]="myForm" (ngSubmit)="onSubmit()">
    <mat-form-field class="example-full-width">
      <input matInput placeholder="What is your name" [formControl]="myForm.controls['name']"/>
      <mat-error *ngIf="myForm.controls['name'].hasError('required')">Required!</mat-error>
      <mat-error *ngIf="myForm.controls['name'].hasError('maxlength')">Too long!</mat-error>
    </mat-form-field>
    <button mat-raised-button color="primary" type="submit" [disabled]="!form.isValid">Submit</button>
</form>