title: Ion-slides doesn’t update dynamic data
body: <p>I am using latest version of ionic 4.0.0
  I am trying to update content of slider on button click but it doesn’t update the content even array values changed in TypeScript code.
  Here us my view code:</p>
  
  <pre><code>&lt;ion-slides class="main-slide" pager=true loop="true" #mainSlider [options]="mainSliderOpts"&gt;
  &lt;ion-slide class="change-display" *ngFor="let product of products;"&gt;
      &lt;div class="item-container"&gt;
          &lt;div class="strike-title"&gt;Strike Price&lt;/div&gt;
          &lt;div class="devider"&gt;&lt;/div&gt;
  
          &lt;p class="description"&gt;
              To at least what price do you think the stock will move from its current price if
              &lt;strong&gt;${{product.price}}&lt;/strong&gt;?
          &lt;/p&gt;
          &lt;div class="lose" [ngClass]="{ 'profit': product.profit &gt; 0,'lose':   product.profit &lt; 0 }"&gt;
              &lt;span *ngIf="product.profit &gt; 0"&gt;+&lt;/span&gt;{{product.profit}}%
          &lt;/div&gt;
  
  
          &lt;div class="price-contract"&gt;
              PRICE PER CONTRACT: &lt;strong&gt;${{product.contractPrice}}&lt;/strong&gt;
          &lt;/div&gt;
  
          &lt;ion-button class="next-btn" (click)=priceSliderChanged() expand="full" color="dark"&gt;Change Values&lt;/ion-button&gt;
  
      &lt;/div&gt;
  &lt;/ion-slide&gt;
  </code></pre>
  
  <p></p>
  
  <p>And Here is my typescript code:</p>
  
  <pre><code>constructor() {
  this.products = [{
          title: 'NFLX',
          price: 313.2,
          prices: [
              297.50,
              295.00,
              292.75,
              290.75
          ],
          profit: 4,
          contractPrice: 400 //defalt price       
      },
      {
          title: 'NFLX 1',
          price: 413.2,
          prices: [
              297.50,
              295.00,
              292.75,
              290.75
          ],
          profit: -6.6,
          contractPrice: 500 //defalt price       
      },
      {
          title: 'NFLX 2',
          price: 213.2,
          prices: [
              297.50,
              295.00,
              292.75,
              290.75
          ],
          profit: -7,
          contractPrice: 300 //defalt price       
      }
  ]
  </code></pre>
  
  <p>}</p>
  
  <p>priceSliderChanged() {</p>
  
  <pre><code>this.mainSlider.getActiveIndex().then((index) =&gt; {
      var activeProduct = this.products[index];
      activeProduct.profit = this.randomIntFromInterval(-5, 6);
      activeProduct.contractPrice = this.randomIntFromInterval(350, 460);
      //setTimeout(()=&gt;{
      this.mainSlider.update().then((d: any) =&gt; {
          // alert(d);
      });
  });
  </code></pre>
  
  <p>}</p>
  
  <p>As you can see contractPrice was changed successfully if I console but not changed in ‘.price-contract’ div.</p>
  
  <p>Thanks for your help.</p>