docs(lifecycle-hooks): SimpleChange -> SimpleChanges #2741 (#2742)

Author: wardbell

public/docs/_examples/lifecycle-hooks/ts/app/counter.component.ts

@@ -1,7 +1,7 @@
 // #docregion
 import {
   Component, Input,
-  OnChanges, SimpleChange,
+  OnChanges, SimpleChanges,
 } from '@angular/core';
 
 import { LoggerService }  from './logger.service';
@@ -22,7 +22,7 @@ export class MyCounterComponent implements OnChanges {
   @Input() counter: number;
   changeLog: string[] = [];
 
-  ngOnChanges(changes: {[propertyName: string]: SimpleChange}) {
+  ngOnChanges(changes: SimpleChanges) {
 
     // Empty the changeLog whenever counter goes to zero
     // hint: this is a way to respond programmatically to external value changes.
@@ -36,7 +36,6 @@ export class MyCounterComponent implements OnChanges {
     let prev = JSON.stringify(chng.previousValue); // first time is {}; after is integer
     this.changeLog.push(`counter: currentValue = ${cur}, previousValue = ${prev}`);
   }
-
 }
 
 /***************************************/

public/docs/_examples/lifecycle-hooks/ts/app/on-changes.component.ts

@@ -2,7 +2,7 @@
 // #docregion
 import {
   Component, Input, OnChanges,
-  SimpleChange, ViewChild
+  SimpleChanges, ViewChild
 } from '@angular/core';
 
 class Hero {
@@ -33,7 +33,7 @@ export class OnChangesComponent implements OnChanges {
   changeLog: string[] = [];
 
   // #docregion ng-on-changes
-  ngOnChanges(changes: {[propertyName: string]: SimpleChange}) {
+  ngOnChanges(changes: SimpleChanges) {
     for (let propName in changes) {
       let chng = changes[propName];
       let cur  = JSON.stringify(chng.currentValue);

public/docs/_examples/lifecycle-hooks/ts/app/peek-a-boo.component.ts

@@ -7,7 +7,7 @@ import {
   OnChanges,
   OnDestroy,
   OnInit,
-  SimpleChange
+  SimpleChanges
 } from '@angular/core';
 import { Component, Input } from '@angular/core';
 import { LoggerService }    from './logger.service';
@@ -51,7 +51,7 @@ export class PeekABooComponent extends PeekABoo implements
   }
 
   // only called for/if there is an @input variable set by parent.
-  ngOnChanges(changes: {[propertyName: string]: SimpleChange}) {
+  ngOnChanges(changes: SimpleChanges) {
     let changesMsgs: string[] = [];
     for (let propName in changes) {
       if (propName === 'name') {