Stop Images from loading in UIWebView

Question

I have a website that I wish to load in a UIWebView, but it is full of images and takes ages to load. The images are useless, and only serve to reduce the usability on the iPhone. I dont own the website so I cannot change the site's actual code.

The webpage is heavily linked in to the web with ASP.NET and AJAX (needs external files), so i dont think it is possible to have it load an HTML string.

I want to stop the images from loading altogether. So how do i block them? Change the HTML code as its loading somehow, or block images from being loaded?

Answer 1

I have 3 thoughts.

1. Use a proxy to filter the HTML
2. Filter the HTML yourself by downloading it first
3. Just download the html and load it using a file:// URL. This will most likely prevent the image references from being resolved - though it will leave ugly squares everywhere

Answer 2

The UIWebView delegate approach does not work, you're right ! new answer:

Right, you need to go one level deeper to catch the NSURLRequest coming from the UIWebView. The blog you're referring to makes use of the NSURLCache and I think this is a good start point:

Did you try to subclass the NSURLCache, and then override the -(NSURLCacheResponse*) cachedResponseForRequest:(NSURLRequest*) request

If you want to avoid the request being performed, you need to return something (as an NSURLCachedResponse). You can for instance, get an image that is statically defined in your app (maybe an PNG with size 0,0 ).

If you return nil, the request will be performed.

I'm using this approach to force the UIWebView to get populated with a local cache. See my detailled answer about this here :

http://stackoverflow.com/questions/1343515/how-to-save-the-content-in-uiwebview-for-faster-loading-on-next-launch/2468722#2468722

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Wrong first answer :/

Add yourself as delegate to the UIWebView (UIWebViewDelegate).

For each image that the UIWebView attempts to load, the delagate gets the following callback invoked :

-(BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType

Just check if the request is related to an image you want to avoid to download. In such a case, just return NO to this callback : the image won't be loaded in the UIWebView.

By using this approach, no change is required on server side.