Untitled

import {App, Platform} from 'ionic-angular';
     import {StatusBar} from 'ionic-native';
     import {HomePage} from './pages/home/home';

     import { FORM_DIRECTIVES, FormBuilder,  ControlGroup,Control, Validators,    AbstractControl } from 'angular2/common';
import {LandingmenuPage} from './pages/landingmenu/landingmenu';
import {FormPage} from './pages/validatelogin/validatelogin';


@App({
  template: '<ion-nav id="nav" [root]="rootPage"></ion-nav>',
  config: {} // http://ionicframework.com/docs/v2/api/config/Config/
})
export class MyApp {
  rootPage: any = FormPage;

  constructor(platform: Platform) {
    platform.ready().then(() => {
      // Okay, so the platform is ready and our plugins are available.
      // Here you can do any higher level native things you might need.
      StatusBar.styleDefault();
    });
  }
}

<ion-navbar *navbar>
    <ion-title>
        Authorization
    </ion-title>
</ion-navbar>

<ion-content class="home" padding>
    <form [ngFormModel]="authForm" >
        <ion-item [class.error]="!username.valid && username.touched">
            <ion-label floating>Username</ion-label>
            <ion-input type="text" value="" [ngFormControl]="username"></ion-input>
        </ion-item>
        <div *ngIf="username.hasError('required') && username.touched"
            class="error-box">* Username is required!</div>
        <div *ngIf="username.hasError('minlength') && username.touched"
            class="error-box">* Minimum username length is 8!</div>
        <div *ngIf="username.hasError('checkFirstCharacterValidator') && username.touched"
            class="error-box">* Username cant't start with number!</div>
        <ion-item floating-label [class.error]="!password.valid && password.touched">
            <ion-label floating>Password</ion-label>
            <ion-input type="text" value="" [ngFormControl]="password" ></ion-input>
        </ion-item>
        <div *ngIf="password.hasError('required') && password.touched"
            class="error-box">* Password is required</div>
        <div *ngIf="password.hasError('minlength') && password.touched"
            class="error-box">* Minimum password length is 8!</div>
        <div *ngIf="password.hasError('checkFirstCharacterValidator') && password.touched"
            class="error-box">* Password cant't start with number!</div>
        <br/><br/>
        <button type="submit" class="custom-button" [disabled]="!authForm.valid" block>Submit</button>
    </form>
</ion-content>

import { Page } from 'ionic-angular';

import { FORM_DIRECTIVES, FormBuilder,  ControlGroup,Control, Validators, AbstractControl } from 'angular2/common';


@Page({
    templateUrl: 'build/pages/form/form.html',
    directives: [FORM_DIRECTIVES]
})

export class FormPage {

    authForm: ControlGroup;
    username: AbstractControl;
    password: AbstractControl;

    constructor(fb: FormBuilder) {
        this.authForm = fb.group({
            'username': ['', Validators.compose([Validators.required, Validators.minLength(8), this.checkFirstCharacterValidator])],
            'password': ['', Validators.compose([Validators.required, Validators.minLength(8),this. checkFirstCharacterValidator])]
        });

        this.username = this.authForm.controls['username'];
        this.password = this.authForm.controls['password'];
    }

    onSubmit(value: string): void {
        if(this.authForm.valid) {
            console.log('Submitted value: ', value);
        }
    }

     checkFirstCharacterValidator(control: Control): { [s: string]: boolean } {
        if (control.value.match(/^d/)) {
            return {checkFirstCharacterValidator: true};
        }
    }
}

<!DOCTYPE html>
<html lang="en" dir="ltr">

<head>
  <title>Ionic</title>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no">
  <meta name="format-detection" content="telephone=no">
  <meta name="msapplication-tap-highlight" content="no">

  <link ios-href="build/css/app.ios.css" rel="stylesheet">
  <link md-href="build/css/app.md.css" rel="stylesheet">
  <link wp-href="build/css/app.wp.css" rel="stylesheet">
</head>

<body>
  <!--<ion-app></ion-app>-->
  <ion-nav #content [root]="rootPage"></ion-nav>

  <!-- cordova.js required for cordova apps -->
  <script src="cordova.js"></script>
  <!-- Polyfill needed for platforms without Promise and Collection support -->
  <script src="build/js/es6-shim.min.js"></script>
  <!-- Zone.js and Reflect-metadata  -->
  <script src="build/js/angular2-polyfills.js"></script>
  <!-- the bundle which is built from the app's source code -->
  <script src="build/js/app.bundle.js"></script>
</body>

</html>