title: Ionic 3 - How to prevent the user from clicking slide pager from slide 0 to slide 2 if slide 1 is not answered
body: <p>I am working on a Ionic 3 questionnaire application where the user cannot go from one slide to another until the question is answered on a slide. I got everything working except pager (this dots) is allowing the user to go from one slide to another even though question# 2 is not answered. </p>
  
  <p>I added the following logic but its not working as expected. Its still allowing me to jump from slide 0 to slide 2. Adding <code>this.slideTo(this.currentIndex)</code> changed the dot to be highlighted for slide 0 however its showing the contents of Slide# 2. </p>
  
  <pre><code>onSlideWillChange(event) {
      let answerNotSelected: boolean = false;
      for (let i: number = 0; i &lt; this.slides.getActiveIndex(); i++) {
        answerNotSelected = this.questionnaire.questions[i].selectedAnswer === undefined;
        if (answerNotSelected) { 
          console.log('Returning from newQuestionIndex ' + this.slides.getActiveIndex() +  ' to current slide:' + this.currentQuestionIndex);
          this.slideTo(this.currentQuestionIndex);
        }
      }  }
  </code></pre>