title: disable button on certain select checkbox
body: <p>I had condition in my reactive <code>form</code> where one <code>checkbox</code> selected, submit <code>button</code> will be enabled, and if there are none <code>checkbox</code> selected, it will remain disabled, the problem is I had <code>selectAll</code> function, which if I clicked, it will selected all the checkbox and enabled submit <code>button</code>, then if I unselect individual <code>checkbox</code> <strong>after select all function</strong>, the submit button should be enabled until all the checkbox is unselect, this is what I had tried: </p>
  
  <p><strong>ts file</strong></p>
  
  <pre><code>  selectAll() {
      this.formReceivedSummons.controls.map(value =&gt; value.get('isChecked').setValue(true));
      return this.disabledButton = false;
    }
  
    changeCheck(event){
      this.disabledButton = !event.target.checked;
    }
  </code></pre>
  
  <p><strong>html file</strong></p>
  
  <pre><code>&lt;div *ngIf="isShowResponse"&gt;
      &lt;p&gt;Inquiry Response&lt;/p&gt;
      &lt;form [formGroup]="form" (ngSubmit)="submitSelectedCheckboxes()"&gt;
          &lt;ng-container formArrayName="receivedSummons" *ngFor="let 
              summon of formReceivedSummons.controls; let i = index"&gt;
              &lt;ng-container [formGroupName]="i"&gt;
                  &lt;input type="checkbox" formControlName="isChecked"
          (change)="changeCheck($event)"&gt;
    {{ summon.get('isChecked').value ? 'selected' : 'select' }}
        &lt;/ng-container&gt;
      &lt;/ng-container&gt;
      &lt;button [disabled]="disabledButton"&gt;Submit&lt;/button&gt;
  &lt;/form&gt;
  &lt;button (click)="selectAll()"&gt;Select All&lt;/button&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>supposed to be after <code>select all</code> function, submit button will enabled until all <code>checkbox</code> is unselected individually then it will disabled, this is my  <a href="https://stackblitz.com/edit/angular-rq4wxc?file=src/app/inquiry-response/inquiry-response.component.ts" rel="nofollow noreferrer">stackblitz demo</a>, I could use any suggestion to solve this problem, </p>