angular 6 from rookie to master - 5 [BookLibrary project - custom directive]

1. Creating a Custom Directive

Angular provides a good range of built-in directives(eg: ngFor), but it is a simple process to create your own directives to solve problems that are specific to your application or to support features that the built-in directives don’t have.

• 1-1) create the directive

counter.directive.ts

import {
  Directive, ViewContainerRef, TemplateRef, Input, Attribute, SimpleChanges
} from '@angular/core';

@Directive({
  selector: '[counterOf]'
})
export class CounterDirective {
  constructor(private container: ViewContainerRef,
              private template: TemplateRef