title: UIWebView white screen on every launch while preloading all tabs
body: <p>Before I present my issue, I want to mention that I tried looking for solutions <a href="https://www.google.co.in/?gfe_rd=cr&amp;ei=bAfPVOmoDYfC8gfw7YDADQ&amp;gws_rd=ssl#q=uiwebview+loadrequest+faster+" rel="nofollow noreferrer"><strong>here</strong></a> and <a href="https://www.google.co.in/?gfe_rd=cr&amp;ei=bAfPVOmoDYfC8gfw7YDADQ&amp;gws_rd=ssl#q=uiwebview+launch+slow+" rel="nofollow noreferrer"><strong>here</strong></a>.<br>
  I am creating a hybrid application which uses native <code>UIWebView</code> for rendering the responsive designed web application. Following is the issue description :<br>
  1. I have a <code>UITabBarController</code>.<br>
  2. Each of the tab has a <code>UIWebView</code>.<br>
  3. I have to preload all tabs.<br>
  4. I am showing a <code>UIActivityIndicator</code> till the content loads on the first tab.<br>
  5. White screen appears for about <strong>8-10 seconds</strong> and then the content starts to appear.<br>
  I will be happy to see this time become <strong>2-4 seconds</strong>.    </p>
  
  <p>Following is my implementation :   </p>
  
  <pre><code>[self performSelectorOnMainThread:@selector(loadAllTabs) withObject:nil waitUntilDone:YES];
  
  -(void) loadAllTabs
  {
      for(UIViewController * viewController in  self.viewControllers){
          if(![[NSUserDefaults standardUserDefaults]boolForKey:@"isSessionExpired"])
          {
              if((int)[self.viewControllers indexOfObject:viewController] != 4)
              {
                  viewController.tabBarItem.tag = (int)[[self viewControllers] indexOfObject:viewController];
                  [viewController view];
              }
          }
      }
  }
  </code></pre>
  
  <p>In WebView controller's <code>viewDidLoad</code> I have :  </p>
  
  <pre><code>[_tgWebView loadRequest:[NSURLRequest requestWithURL:homeURL]];  
  </code></pre>
  
  <p>I was looking forward to <a href="https://stackoverflow.com/questions/12466993/ios-6-uiwebview-loadhtmlstring-not-working-properly/13547296#13547296"><strong>suppressesIncrementalRendering</strong></a>, but since I am preloading all tabs, this does not work. 
  Since my app supports <strong>iOS 7+</strong>, thus <a href="http://developer.telerik.com/featured/why-ios-8s-wkwebview-is-a-big-deal-for-hybrid-development/" rel="nofollow noreferrer"><strong>WKWebView</strong></a> can't be applied here.<br>
  I also thought of <a href="https://stackoverflow.com/questions/28234607/increase-launch-image-duration-while-all-tabs-load"><strong>increasing</strong></a> the launch image duration but learned that is won't be a good practice.<br>
  Can this be implemented using <strong>GCD</strong>?<br>
  Please bring out the pitfalls in my implementations so that my application makes better performance.</p>