How to Pass data from child to parent component Angular

I have a component named search_detail which has another component inside it named calendar,

SearchDetail_component.html

 <li class="date">
   <div class="btn-group dropdown" [class.open]="DatedropdownOpened">
   <button type="button" (click)="DatedropdownOpened = !DatedropdownOpened"   class="btn btn-default dropdown-toggle" data-toggle="dropdown"
aria-haspopup="true" [attr.aria-expanded]="dropdownOpened ? 'true': 'false'">
      Date <span class="caret"></span>
  </button>
  <ul class="dropdown-menu default-dropdown">
     <calendar  ></calendar>
     <button > Cancel </button>
     <button (click)="setDate(category)"> Ok </button>
   </ul>                            
 </div>
</li>

SearchDetail_component.ts

import 'rxjs/add/observable/fromEvent';
@Component({
    selector: 'searchDetail',
    templateUrl: './search_detail.component.html',
    moduleId: module.id

})

Calendar.component.ts

import { Component, Input} from '@angular/core'; 
@Component({
    moduleId:module.id,
    selector: 'calendar',
    templateUrl: './calendar.component.html'
})

    export class CalendarComponent{
      public fromDate:Date = new Date();    
      private toDate:Date = new Date();
      private events:Array<any>;
      private tomorrow:Date;
      private afterTomorrow:Date;
      private formats:Array<string> = ['DD-MM-YYYY', 'YYYY/MM/DD', 'DD.MM.YYYY', 'shortDate'];
      private format = this.formats[0];
      private dateOptions:any = {
        formatYear: 'YY',
        startingDay: 1
      };
      private opened:boolean = false;

      public getDate():number {
        return this.fromDate.getDate()  || new Date().getTime();
      }
    }

I want to access the startdate and enddate on click of the ok button in the search detail page. how can i do?

Solution 1:

Register the EventEmitter in your child component as the @Output:

@Output() onDatePicked = new EventEmitter<any>();

Emit value on click:

public pickDate(date: any): void {
    this.onDatePicked.emit(date);
}

Listen for the events in your parent component's template:

<div>
    <calendar (onDatePicked)="doSomething($event)"></calendar>
</div>

and in the parent component:

public doSomething(date: any):void {
    console.log('Picked date: ', date);
}

It's also well explained in the official docs: Component interaction.

Solution 2:

In order to send data from child component create property decorated with output() in child component and in the parent listen to the created event. Emit this event with new values in the payload when ever it needed.

@Output() public eventName:EventEmitter = new EventEmitter();

to emit this event:

this.eventName.emit(payloadDataObject);