I want to disable all options once two options checked. I have tried (ionChange) but this event fired after clicking the "Ok" button of the select model. Is there any other event which execute before "ionChange"?

 <ion-item>
     <ion-label>Values</ion-label>
     <ion-select formControlName="Values" multiple="true">
          <ion-option value="1">1 value</ion-option>
          <ion-option value="2">2 value</ion-option>
          <ion-option value="3">3 value</ion-option>
          <ion-option value="4">4 value</ion-option>
         <ion-option value="5">5 value</ion-option>
    </ion-select>
 </ion-item>

I want to disable all options once two options checked. I have tried (ionChange) but this event fired after clicking the "Ok" button of the select model. Is there any other event which execute before "ionChange"?

 <ion-item>
     <ion-label>Values</ion-label>
     <ion-select formControlName="Values" multiple="true">
          <ion-option value="1">1 value</ion-option>
          <ion-option value="2">2 value</ion-option>
          <ion-option value="3">3 value</ion-option>
          <ion-option value="4">4 value</ion-option>
         <ion-option value="5">5 value</ion-option>
    </ion-select>
 </ion-item>

• javascript
• ionic-framework
• ionic3

• 1 If you need to add some custom logic, maybe using a modal (with some css style rules to make it look like an alert) would be a better option. – sebaferreras Commented Nov 30, 2017 at 9:27
• 1 Hi @shah. Did you ever get an answer to this? Because I am faced with the very same problem – Anele Commented Aug 1, 2019 at 19:37

2 Answers 2

Below code will satisfy your requirement. Change the check box limit to increase or decrease the number of options that can be selection. Tips to optimization is also weled.

Working demo

ponent file

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {

  selectedIng : Array<any>=[];
  numberOfChecks : number=1;
  checkBoxLimit : any =1;
  constructor(public navCtrl: NavController) {
    this.pizzaIng=[
      {name : "Pepperoni", checked : false},
      {name : "Sasuage", checked : true},
      {name : "Mushrooms", checked : false}
    ];
    this.selectedIng=[{name : "Sasuage", checked : true}];    
  }

  updateIng(ing){
      if(ing.checked === true){
      this.selectedIng.push(ing);
      this.numberOfChecks++;
      }else{
        this.selectedIng=this.pizzaIng.filter((ingr)=>{
          console.log(ingr['checked'])
          return ingr['checked']===true;
        })
        this.numberOfChecks--;
      }

    console.log(this.selectedIng);
    console.log(this.numberOfChecks);
  }
}

HTML file

  <ion-list>
  <ion-item  *ngFor="let ing of pizzaIng; let i = index">
    <ion-label>{{ing.name}}</ion-label>
    <ion-checkbox [(ngModel)]="ing.checked"  [disabled]="ing.checked==false && numberOfChecks>=checkBoxLimit"  (ionChange)="updateIng(ing)"></ion-checkbox>
  </ion-item>
</ion-list>

Use [disabled] property in on-change function You can perform disable action and other functionality using the selected value