The State of CSS 2020 survey is running. It’s important for fifguring out where CSS should go next, and what people actually know.  

Although it sounds like HttpContextBase should be the base class of HttpContext, I just figured out that this is not the case. 

The purpose is to save you time and quickly filter out DB-experienced guys from the ones that just claim to be. 

Table of Contents

1. Getting Started
2. Scenes and Scene Management
3. User Interface
4. 2-D Graphics and Sprites
5. Input
6. Animation
7. Audio
8. Implementing Gameplay 

 >ng g m CustomValidators -m app.module --routing

 >ng g c CustomValidators/user-register

 >ng g cl CustomValidators/user

export class User {
  constructor(
    public username: string = "",
    public email: string = "", 
    public password: string = "", 
    public confirmPassword: string = "" 
  ) {}
}

 >ng g d CustomValidators/EmailValidator -m custom-validators.module

import { Directive } from "@angular/core";
import { AbstractControl, NG_VALIDATORS, Validator } from "@angular/forms";

@Directive({
  selector:
    "[appEmailValidator][formControlName],[appEmailValidator][formControl],[appEmailValidator][ngModel]",
  providers: [
    {
      provide: NG_VALIDATORS,
      useExisting: EmailValidatorDirective,
      multi: true
    }
  ]
})
export class EmailValidatorDirective implements Validator {
  validate(element: AbstractControl): { [key: string]: any } {
    const emailRegex = /\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*/;
    const valid = emailRegex.test(element.value);
    return valid ? null : { appEmailValidator: true };
  }
}

<input #email="ngModel" required appEmailValidator type="text" class="form-control" 
name="email" [(ngModel)]="model.email">

selector:
"[appEmailValidator][formControlName],[appEmailValidator][formControl],[appEmailValidator][ngModel]",

"apps": [
{
   // ...
   "prefix": "app",

 selector: "[appEmailValidator]"

  providers: [
    {
      provide: NG_VALIDATORS,
      useExisting: EmailValidatorDirective,
      multi: true
    }

 export class EmailValidatorDirective implements Validator {

 validate(element: AbstractControl): { [key: string]: any }

validate(element: AbstractControl): { [key: string]: any } {
  const emailRegex = /\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*/;
  const valid = emailRegex.test(element.value);
  return valid ? null : { appEmailValidator: true };
}

<input #email="ngModel" required appEmailValidator type="text" class="form-control"
name="email" [(ngModel)]="model.email">

 { required:true }

{ minlength : {
     requiredLength : 3,
     actualLength : 1
   }
}

 { appEmailValidator: true }

<div class="alert alert-danger"  *ngIf="email.errors.appEmailValidator">
The entered email is not valid.
</div>

public password: string = "",
public confirmPassword: string = ""

 >ng g d CustomValidators/EqualValidator -m custom-validators.module

import { Directive, Attribute } from "@angular/core";
import { Validator, AbstractControl, NG_VALIDATORS } from "@angular/forms";

@Directive({
  selector:
    "[appValidateEqual][formControlName],[appValidateEqual][formControl],[appValidateEqual][ngModel]",
  providers: [
    {
      provide: NG_VALIDATORS,
      useExisting: EqualValidatorDirective,
      multi: true
    }
  ]
})
export class EqualValidatorDirective implements Validator {
  constructor(@Attribute("compare-to") public compareToControl: string) {}

  validate(element: AbstractControl): { [key: string]: any } {
    const selfValue = element.value;
    const otherControl = element.root.get(this.compareToControl);

    console.log("EqualValidatorDirective", {
       thisControlValue: selfValue,
       otherControlValue: otherControl ? otherControl.value : null
    });

    if (otherControl && selfValue !== otherControl.value) {
      return {
        appValidateEqual: true // Or a string such as 'Password mismatch.' or an abject.
      };
    }

    if (
      otherControl &&
      otherControl.errors &&
      selfValue === otherControl.value
    ) {
      delete otherControl.errors["appValidateEqual"];
      if (!Object.keys(otherControl.errors).length) {
        otherControl.setErrors(null);
      }
    }

    return null;
  }
}

export class EqualValidatorDirective implements Validator {
  constructor(@Attribute("compare-to") public compareToControl: string) {}

<input #password="ngModel" required type="password" class="form-control"
appValidateEqual compare-to="confirmPassword" name="password" [(ngModel)]="model.password">

export class EqualValidatorDirective implements Validator {
  constructor(@Attribute("compare-to") public compareToControl: string) {}

  validate(element: AbstractControl): { [key: string]: any } {
    const selfValue = element.value;
    const otherControl = element.root.get(this.compareToControl);

    console.log("EqualValidatorDirective", {
       thisControlValue: selfValue,
       otherControlValue: otherControl ? otherControl.value : null
    });

    if (otherControl && selfValue !== otherControl.value) {
      return {
        appValidateEqual: true // Or a string such as 'Password mismatch.' or an abject.
      };
    }

    if (otherControl && otherControl.errors && selfValue === otherControl.value) {
      delete otherControl.errors["appValidateEqual"];
      if (!Object.keys(otherControl.errors).length) {
        otherControl.setErrors(null);
      }
    }

    return null;

import { NgForm } from "@angular/forms";
import { User } from "./../user";
import { Component, OnInit } from "@angular/core";

@Component({
  selector: "app-user-register",
  templateUrl: "./user-register.component.html",
  styleUrls: ["./user-register.component.css"]
})
export class UserRegisterComponent implements OnInit {
  model = new User();

  constructor() {}

  ngOnInit() {}

  submitForm(form: NgForm) {
    console.log(this.model);
    console.log(form.value);
  }
}

<div class="container">
  <h3>Registration Form</h3>
  <form #form="ngForm" (submit)="submitForm(form)" novalidate>

    <div class="form-group" [class.has-error]="username.invalid && username.touched">
      <label class="control-label">User Name</label>
      <input #username="ngModel" required maxlength="8" minlength="4" type="text"
        class="form-control" name="username" [(ngModel)]="model.username">
      <div *ngIf="username.invalid && username.touched">
        <div class="alert alert-info">
          errors: {{ username.errors | json }}
        </div>
        <div class="alert alert-danger"  *ngIf="username.errors.required">
          username is required.
        </div>
        <div class="alert alert-danger"  *ngIf="username.errors.minlength">
          username should be minimum {{username.errors.minlength.requiredLength}} characters.
        </div>
        <div class="alert alert-danger"  *ngIf="username.errors.maxlength">
          username should be max {{username.errors.maxlength.requiredLength}} characters.
        </div>
      </div>
    </div>

    <div class="form-group" [class.has-error]="email.invalid && email.touched">
      <label class="control-label">Email</label>
      <input #email="ngModel" required appEmailValidator type="text" class="form-control"
        name="email" [(ngModel)]="model.email">
      <div *ngIf="email.invalid && email.touched">
        <div class="alert alert-info">
          errors: {{ email.errors | json }}
        </div>
        <div class="alert alert-danger"  *ngIf="email.errors.required">
          email is required.
        </div>
        <div class="alert alert-danger"  *ngIf="email.errors.appEmailValidator">
          The entered email is not valid.
        </div>
      </div>
    </div>

    <div class="form-group" [class.has-error]="password.invalid && password.touched">
      <label class="control-label">Password</label>
      <input #password="ngModel" required type="password" class="form-control"
        appValidateEqual compare-to="confirmPassword" name="password" [(ngModel)]="model.password">
      <div *ngIf="password.invalid && password.touched">
        <div class="alert alert-info">
          errors: {{ password.errors | json }}
        </div>
        <div class="alert alert-danger"  *ngIf="password.errors.required">
          password is required.
        </div>
        <div class="alert alert-danger"  *ngIf="password.errors.appValidateEqual">
          Password mismatch. Please complete the confirmPassword .
        </div>
      </div>
    </div>

    <div class="form-group" [class.has-error]="confirmPassword.invalid && confirmPassword.touched">
      <label class="control-label">Retype password</label>
      <input #confirmPassword="ngModel" required type="password" class="form-control"
        appValidateEqual compare-to="password" name="confirmPassword" [(ngModel)]="model.confirmPassword">
      <div *ngIf="confirmPassword.invalid && confirmPassword.touched">
        <div class="alert alert-info">
          errors: {{ confirmPassword.errors | json }}
        </div>
        <div class="alert alert-danger"  *ngIf="confirmPassword.errors.required">
          confirmPassword is required.
        </div>
        <div class="alert alert-danger"  *ngIf="confirmPassword.errors.appValidateEqual">
          Password mismatch.
        </div>
      </div>
    </div>

    <button class="btn btn-primary" [disabled]="form.invalid" type="submit">Ok</button>
  </form>
</div>

>npm install
>ng build --watch

>dotnet restore
>dotnet watch run

• To import various symbols please adjust the paths in the following way:
  
• angular2/core -> @angular/core
  
• angular2/compiler -> @angular/compiler
  
• angular2/common -> @angular/common
  
• angular2/platform/browser -> @angular/platform-browser (applications with precompiled templates) + @angular/platform-browser-dynamic (applications that compile templates on the fly)
  
• angular2/platform/server -> @angular/platform-server
  
• angular2/testing -> @angular/core/testing (it/describe/..) + @angular/compiler/testing (TestComponentBuilder) + @angular/platform-browser/testing
  
• angular2/upgrade -> @angular/upgrade
  
• angular2/http -> @angular/http
  
• angular2/router -> @angular/router-deprecated (snapshot of the component router from beta.17 for backwards compatibility)
  
• new package: @angular/router - component router with several breaking changes