Angular 2 - detect when a bonded property receives a value

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6 Answers

bondeddetectreceivesvalueangularproperty
90%

Created a custom change property to the <counter> template, using () event binding syntax, like we learned when we created our first component this signifies some kind of event (such as a click when used on a native element Node),,Essentially, we’re just telling Angular here to lookup update as the property to be bound to, and we can continue using this

Example_snippet/controller/utility/_bonded.js/ import { Component } from '@an. . .
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  template: `
    <div class="app">
      Parent: {{ myCount }}
      <counter
        [count]="myCount"
        (change)="countChange($event)">
      </counter>
    </div>
  `
})
export class AppComponent {
  myCount: number = 10;
  countChange(event) {

  }
}
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88%

We say we have bound the value true to the property called hidden,,Angular doesn’t manipulate HTML attributes, it manipulates DOM properties because the DOM is what actually gets displayed

Example_snippet/controller/utility/_bonded.js/ <p class="card-text" hidden>{{. . .
<p class="card-text" hidden>{{joke.punchline}}</p>
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72%

Respond when Angular sets or resets data-bound input properties, The method receives a SimpleChanges object of current and previous property values

Example_snippet/controller/utility/_bonded.js/ content_copy . . .
      content_copy

      @Directive({
         selector: '[appPeekABoo]'
      })
      export class PeekABooDirective implements OnInit {
         constructor(private logger: LoggerService) {}

         // implement OnInit's `ngOnInit` method
         ngOnInit() {
            this.logIt(`OnInit`);
         }

         logIt(msg: string) {
            this.logger.log(`#${nextId++} ${msg}`);
         }
      }
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65%

Here we are creating a parent component and adding child to it,form

Example_snippet/controller/utility/_bonded.js/ Implementation of Two-way bind. . .
Implementation of Two - way binding:
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75%

I would like how to know when a bonded property receives a value, even if it's the same value,, Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers ,Please be sure to answer the question

Example_snippet/controller/utility/_bonded.js/ this.bondedProperty = 10; . . .
this.bondedProperty = 10;
Step 2 continued with this.bondedProperty = { 'value. . .
this.bondedProperty = {
   'value': 10
};
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40%

Another option to intercept for any change in any of the input property is to use the Angular’s ngOnChanges event:,In the child component class, we can define our @Input property itemusing typescript accessors that would allow us to intercept whenever the property is set to a new value, like shown below:,Here is the plunkr example of the above two approaches:,Child component has two options to intercept the change to its input properties: 1, Using the typescript’s class member accessors(getter/setter) to define the input property item or 2

Example_snippet/controller/utility/_detect.js/ <item-details *ngIf="itemSelec. . .
<item-details *ngIf="itemSelected" [item]="itemSelected" [notifyItemProcessed]="processOrderItems"></item-details>