How to check if UIWebView loads from NSURLCache?

1
votes

I actually have more than one question regarding this... I'm still new to NSURLCache and UIWebViews but somehow got the basics down I think.

Anyway, I was able to successfully implement Caching for my UIWebView(I think). I initialized the NSURLCache. My UIWebView loads its contents with the loadRequest: method. I assigned the ViewController that owns the UIWebView as it's delegate. I also had the ViewController implement NSURLConnectionDataDelegate. I implemented the connection:willCacheResponse: method just to log a message in the console so I could check that caching was done. I also logged the current disk and memory usage. It increases after the caching so I can see that it did work.

However, when I load the page again, I think the request is sent again to the server because the connection delegate methods like connection:didReceiveResponse: and connection:willCacheResponse are being called.

I also wanted to try getting the cachedResponse from the cache by using cachedResponseForRequest:. I called this method in webViewDidFinishLoad: but it always returns null. Did caching really work?

How can you tell if the WebView loaded from the cache? Am I misusing cachedResponseForRequest:? And on another note, what proper Control-Cache header values should be present in the very least for caching? I'm testing on google's homepage URL and it returns the private value for its Cache Control header but I can see that caching works because the connection:willCacheResponse: is called.

Help please?

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ioscachinguiwebviewnsurlcache

1 Answers

0
votes

If you run a HTTP proxy like Charles or Fiddler you can keep tabs on what network traffic is actually going out over the wire(less).

You can also inspect the request/response headers to see whether the response is indeed destined for the cache.

Note that in some cases you might see a conditional-GET (returns a 304) meaning the client asked for content that it has in its cache, but only wants to download the content if the server has a more recent version.