title: React Native: Force reload of TabBarIOS.item
body: <p>I have a TabBar based app in React Native.
  Multiple tabs use the same datasource (AsyncStorage).
  If I'm now updating the data in one tab and open the other one, the old data is displayed.
  I can't figure out, how to force a reload every time the item become active.</p>
  
  <ol>
  <li>FavoritesView: display saved data</li>
  <li>ExploreView: Manipulate saved data</li>
  <li><p>FavoritesView: expired data gets displayed (--> force reload)</p>
  
  <p></p>
  
  <pre><code>&lt;TabBarIOS.Item
  title="Explore"
  icon={{uri:'ic_explore'}}
    selected={this.state.selectedTab === 'exploreTab'}
    onPress={() =&gt; {
      this.setState({
        selectedTab: 'exploreTab'
      });
    }}&gt;
    &lt;ExploreView/&gt;
  &lt;/TabBarIOS.Item&gt;
  
  &lt;TabBarIOS.Item
    title="Favorites"
    icon={{uri:'ic_favorite_border'}}
    selected={this.state.selectedTab === 'favoriteTab'}
    onPress={() =&gt; {
      this.setState({
        selectedTab: 'favoriteTab'
      });
    }}&gt;
     // Reload this
    &lt;FavoritesView/&gt;
  &lt;/TabBarIOS.Item&gt;
  
  &lt;TabBarIOS.Item
    systemIcon="more"
    selected={this.state.selectedTab === 'moreTab'}
    onPress={() =&gt; {
      this.setState({
        selectedTab: 'moreTab'
      });
    }}&gt;
    &lt;MoreView/&gt;
  &lt;/TabBarIOS.Item&gt;
  </code></pre>
  
  <p></p></li>
  </ol>
  
  <p>I already tried to set a new state to trigger an update, but it doesn't seem to change anything.</p>
  
  <pre><code>&lt;TabBarIOS.Item
        title="Favorites"
        icon={{uri:'ic_favorite_border'}}
        selected={this.state.selectedTab === 'favoriteTab'}
        onPress={() =&gt; {
          this.setState({
            selectedTab: 'favoriteTab',
            forceUpdate: Math.random()
          });
        }}&gt;
        &lt;FavoritesView forceUpdate={this.state.forceUpdate}/&gt;
  &lt;/TabBarIOS.Item&gt;
  </code></pre>