Detaching and Tearing Down with willDestroyElement

You can remove the component elements from the DOM by triggering the willDestroyElement hook.

Syntax

import Ember from 'ember';

export default Ember.Component.extend ({
   ...
   willDestroyElement() {
      //code here    
   },
   ...
})

Example

The example given below describes the use of willDestroyElement hook, which removes the component elements from the DOM. Create a controller with name index and open the file from app/controller/ to add the following code −

import Ember from 'ember';

export default Ember.Controller.extend ({
   showComponent: true,
   laterCount: 0,
  
   buttonText: Ember.computed('showComponent', function() {
      let showing = Ember.get(this, 'showComponent');
      if (showing) {
         return 'Remove';
      } else {
         return 'Add';
      }
   }),
  
   actions: {
      toggleComponent() {
         this.toggleProperty('showComponent');
      },
    
      updateLaterCount() {
         Ember.set(this, 'laterCount', Ember.get(this, 'laterCount') + 1);
      }
   }
});

Create a component with the name post-action, which will get defined under app/components/.

Open the post-action.js file and add the following code −

import Ember from 'ember';

export default Ember.Component.extend ({
   runLater: null,
  
   didInsertElement() {
      let timeout = Ember.run.later(this, function() {
         Ember.Logger.log('fired this after 1 seconds...');
         this.sendAction();
      }, 500);
    
      Ember.set(this, 'runLater', timeout);
   },
  
   willDestroyElement() {
      Ember.run.cancel(Ember.get(this, 'runLater'));
   }
});

Now open the component template file post-action.hbs with the following code −

<h2>Tutorialspoint</h2>

Open the index.hbs file and add the following code −

<h5>Count for clicks: {{laterCount}}</h5>
<button {{action 'toggleComponent'}}>{{buttonText}}</button>
{{#if showComponent}}
   {{post-action action="updateLaterCount"}}
{{/if}}
{{outlet}}

Output

Run the ember server; you will receive the following output −

Initially number of clicks will be 1. When you click the Remove button, it will remove the text −

Next, click the Add button, it will increment the number of clicks and display the text −