title: ngOnChanges not getting Fired
body: <p>I am testing the ngOnChanges method in my running code. But it seems the ngOnchanges isnt getting called though it compiles . Below is my code. </p>
  
  <p>create-employee.component.html:</p>
  
  <pre><code>&lt;form #employeeForm="ngForm"  (ngSubmit)=saveEmployee(employeeForm)&gt;
    &lt;div class="panel panel-primary"&gt;
      &lt;div class="panel-heading"&gt;
        &lt;h3 class="panel-title"&gt; Create Employee&lt;/h3&gt;
      &lt;/div&gt;
      &lt;div class="panel-body"&gt;
        &lt;div class="form-group" [class.has-error]="fullName.invalid &amp;&amp; fullName.touched" [class.has-success]="fullName.valid"&gt;
          &lt;label for="fullName"class="control-label"&gt;Full Name&lt;/label&gt;
          &lt;input required type ="text"  class= "form-control" 
            name="fullName1" 
            [(ngModel)]="employee.fullName"
            #fullName="ngModel" id="fullName"&gt;
          &lt;span class="help-block" *ngIf="fullName.invalid &amp;&amp; fullName.touched"&gt;
            Full Name is Required
          &lt;/span&gt;
        &lt;/div&gt;
      &lt;/div&gt;
      &lt;div class="panel-footer"&gt;
       &lt;button  [disabled]="employeeForm.invalid" type ="submit" class= "btn btn-primary" &gt; Save &lt;/button&gt;
      &lt;/div&gt;
    &lt;/div&gt;
    {{employeeForm.value|json}}
    employee: {{employee| json}}
    employee.isActive: {{employee.isActive}}
  &lt;/form&gt;
  </code></pre>
  
  <p>create-employee.component.ts:</p>
  
  <pre><code>import { Component,OnChanges, OnInit ,SimpleChanges,Input} from '@angular/core';
  import { NgForm } from '@angular/Forms';
  import { Department } from '../models/department.model';
  import { BsDatepickerModule,BsDatepickerConfig} from 'ngx-bootstrap/datepicker';
  import { Employee } from '../models/employee.model';
  
  @Component({
    selector: 'app-create-employee',
    templateUrl: './create-employee.component.html',
    styleUrls: ['./create-employee.component.css']
  })
  export class CreateEmployeeComponent implements OnInit, OnChanges {
  
    constructor() {}
  
    saveEmployee( employeeForm:NgForm): void {
      console.log(employeeForm);
      console.log("employee = " + JSON.stringify(this.employee));  
    }
  
  
    allMsgChangeLogs: string[] = [];
    allEmployeeChangeLogs: string[] = [];
  
    @Input() employee:Employee = { 
      id: null,
      fullName: 'Jay',
    }
    ngOnChanges(changes: SimpleChanges): void {
      console.log("inside on changes"); 
      for (let propName in changes) {  
  
        let change = changes[propName];
  
        let curVal  = JSON.stringify(change.currentValue);
        let prevVal = JSON.stringify(change.previousValue);
        let changeLog = `${propName}: currentValue = ${curVal}, previousValue = ${prevVal}`;
  
        if (propName === 'employee') {
            this.allEmployeeChangeLogs.push(changeLog);
            console.log(changeLog);
        } else {
           console.log("change detecetd");
        }
      }
    }
  </code></pre>
  
  <p>The model object employee being used in the form is as :  employee.model.ts:</p>
  
  <pre><code>export class Employee {
      id: number;
      fullName: string;
  }
  </code></pre>
  
  <p>ngOnChanges method isnt getting fired at all. Any inputs?</p>