Angular2: Forms with Material Design: ng-message doesn't work like it should

Question

Because I'm fairly new with Angular2 I've probably made a mistake to do with data binding from the .html sheet to the .ts file but I can't work the current problem out. I have a form with an input field and this field has the required -and maxlength-tag. I have these restrictions display an error when not followed by using Material Design. And I have a button to post the input.

<form name="postFeedForm">
      <table>
        <tr>
          <td class="long-td">
            <md-input-container class="md-block | long-inputfield">
              <input mdInput name="newDescription" [(ngModel)]="newDescription" #description placeholder="What's up?" required maxlength="150">
              <md-hint align="end">{{description.value.length}} / 150</md-hint>
              <div ng-messages="postFeedForm.description.$error" ng-show="postFeedForm.description.$dirty">
                <div ng-message="required">Please enter a description</div>
                <div ng-message="md-maxlength">Exceeded the maximum characters {{description.value.length}} / 150</div>
              </div>
            </md-input-container>
          </td>
          <td>
            <button md-button class="text-upper | spikes_red" type="submit" (click)="post()">Post</button>
          </td>
        </tr>
      </table>
    </form>

I'm not sure about the "#description"-tag but without it I get an error. The problem is that I've followed different examples and I probably mixed them up. What I'm trying to do can be found here (including Code Pen): https://material.angularjs.org/latest/demo/input

The .ts file:

export class DashboardComponent {
  newDescription: string;

  post() {
    // Post some feed
    ...
    description: this.newDescription,
    ...
  }
}

Source: https://github.com/angular/material2/blob/master/src/demo-app/input/input-demo.html

Answer 1

Now with "2.0.0-beta.3" you can use 'md-error' for error validation:

HTML:

<md-input-container>
    <input mdInput placeholder="email" [formControl]="emailFormControl" required>
    <md-error *ngIf="emailFormControl.hasError('required')">
    This field is required
    </md-error>
    <md-error *ngIf="emailFormControl.hasError('pattern')">
    Please enter a valid email address
    </md-error>
</md-input-container>

TS:

import { FormControl, Validators } from '@angular/forms';
...
const EMAIL_REGEX = /^[a-zA-Z0-9.!#$%&’*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*$/;
....
export class PageComponent {
....
public emailFormControl = new FormControl('', [Validators.required, Validators.pattern(EMAIL_REGEX)]);
....
}