UIWebView reloading baseUrl when setting contents from NSURLConnectionDataDelegate - ios

Question

I'm trying to create an single UIWebView-based application. Its main purpose is to provide authentication to a few websites using NTLM or Basic authentication, without the user having to input the username/password for every website when he/she changes his password (the websites share the user/password database).
In order to do that, I'm "overriding" the loading of page data for the UIWebView, so that I can intercept the HTTP response codes and ask the user for a password every time I detect a 401 Unauthorized response.
I've set up a NSURLConnectionDataDelegate to handle the requests as such:
#interface LPURLConnectionDelegate : NSObject<NSURLConnectionDataDelegate>
{
UIWebView* _webView;
NSMutableURLRequest* _request;
NSURLConnection* _connection;
NSString* _encoding;
NSString* _mimeType;
NSMutableData* _data;
}
- (LPURLConnectionDelegate*) initWithWebView:(UIWebView *)webView;
- (void) loadPageWithRequest: (NSURLRequest*)request;
- (void)connection:(NSURLConnection *)connection willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge;
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error;
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response;
- (BOOL)connectionShouldUseCredentialStorage:(NSURLConnection *)connection;
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data;
- (void)connectionDidFinishLoading:(NSURLConnection *)connection;
#end
#implementation LPURLConnectionDelegate
- (void) loadPageWithRequest: (NSURLRequest*)request
{
_request = [request mutableCopy];
if(!_data)
{
_data = [NSMutableData dataWithCapacity:0];
[_data retain];
}
[_data setLength:0];
if(_connection)
{
[_connection cancel];
[_connection release];
_connection = nil;
}
_connection = [[NSURLConnection alloc] initWithRequest:_request delegate:self startImmediately:YES];
}
- (void)connection:(NSURLConnection *)connection willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge
{
LPAppDelegate* delegate = [LPAppDelegate getInstance];
NSURLCredential* credential = [NSURLCredential credentialWithUser:[delegate getUsername] password:[delegate getPassword] persistence:NSURLCredentialPersistenceForSession];
[[challenge sender] useCredential:credential forAuthenticationChallenge:challenge];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
//handle connection failed
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
NSLog(#"Connection did receive response");
NSHTTPURLResponse* httpResponse = (NSHTTPURLResponse*)response;
_mimeType = [httpResponse MIMEType];
_encoding = [httpResponse textEncodingName];
//handle status - if the status is 401, the connection is canceled and the user is asked for his new password
}
- (BOOL)connectionShouldUseCredentialStorage:(NSURLConnection *)connection
{
return YES;
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[_data appendData:data];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
[_webView loadData:_data MIMEType:_mimeType textEncodingName:_encoding baseURL:[_request URL]];
}
#end
My UIWebViewDelegate looks like this:
#interface LPWebViewDelegate : NSObject<UIWebViewDelegate>
- (void)webViewDidStartLoad:(UIWebView *)webView;
- (void)webViewDidFinishLoad:(UIWebView *)webView;
- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error;
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType;
#end
#implementation LPWebViewDelegate
- (void) webViewDidStartLoad:(UIWebView *)webView
{
}
- (void) webViewDidFinishLoad:(UIWebView *)webView
{
//handle success
}
- (BOOL) webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
LPURLConnectionDelegate* connectionDelegate = [[LPURLConnectionDelegate alloc] initWithWebView:webView];
[connectionDelegate loadPageWithRequest:request];
return NO;
}
- (void) webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error
{
//handle fail
}
#end
Basically, what I'm trying to do is tell the UIWebView not to load any page by itself, letting me handle the request to load the page. When the request completes and the user is authenticated, I'm trying to set the data using the UIWebView::loadData:MIMEType:textEncodingName:baseUrl method.
The problem here is that after setting the UIWebView's data from the NSURLConnectionDataDelegate, the UIWebView reloads the page set as baseURL (at least in the simulator - I haven't tried the code on an actual device just yet).
Does anyone know a way to set data to UIWebViews in such way that it doesn't reload the page(*)?
*) I know that I could just let the UIWebView load the page after I make the NSURLConnection to check for authentication (or in parallel), but I'm trying to avoid requesting the page header twice for each page.
Note: the code is not complete, I've extracted what I consider to be the most relevant parts for this issue.

Answer 1

Implement NSURLProtocol class. It essentially a abstract class that allows subclasses to define the URL loading behavior of HTTP schemes
Check this tutorial out here