Listening for events in a UIWebView (iOS)
Solution 1
You can use the UIWebViewDelegate:
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
The UIWebViewNavigationType values are :
enum {
UIWebViewNavigationTypeLinkClicked,
UIWebViewNavigationTypeFormSubmitted,
UIWebViewNavigationTypeBackForward,
UIWebViewNavigationTypeReload,
UIWebViewNavigationTypeFormResubmitted,
UIWebViewNavigationTypeOther
};typedef NSUInteger UIWebViewNavigationType;
Can check this and then look at the NSURLRequest to get info about that
Solution 2
Use a custom scheme. When the user taps the button, ping a url with the custom scheme (myScheme://buttonTapped) and either:
Catch this in the webview delegate method
shouldStartLoadWithRequest...
(ie check if the URL contains your custom scheme) and route it to the appropriate objective c selector. OrRegister a custom URL protocol and set it up to handle your custom URL scheme. Something like the below:
@implementation MyURLProtocol + (BOOL)canInitWithRequest:(NSURLRequest *)request { return [[[request URL] scheme] isEqualToString:@"myScheme"]; } + (NSURLRequest *)canonicalRequestForRequest:(NSURLRequest *)request { return request; } - (void)startLoading { NSURLRequest * request = [self request]; id client = [self client]; NSData * data = [NSMutableData dataWithCapacity:0]; NSHTTPURLResponse * response = [[[NSHTTPURLResponse alloc] initWithURL:[request URL] statusCode:200 HTTPVersion:@"HTTP/1.1" headerFields:nil] autorelease]; [client URLProtocol:self didReceiveResponse:response cacheStoragePolicy:NSURLCacheStorageNotAllowed]; [client URLProtocol:self didLoadData:data]; [client URLProtocolDidFinishLoading:self]; [[NSNotificationCenter defaultCenter] postNotificationName:kSchemeNotification object:nil userInfo:payload]; } - (void)stopLoading { }
Comments
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WendiKidd almost 2 years
I'm trying to listen for an event (specifically a button click) from a webpage I have opened in a UIWebView in my iOS app. I know that in other languages there are ways to attach event listeners to certain web calls, but I haven't yet found a way to do it in Objective-C. I also haven't found anyone online who says it can't be done, so I decided I should ask. I saw in the documentation that you can make Objective-C calls from Javascript, but I do not have control of the webpage I am wanting to monitor. So I need a solution that allows me to listen for this event entirely in Objective-C.
EDIT: If specifics would help, I am trying to allow the user to make a wallpost on Facebook. I am loading the Facebook sharer page in a UIWebview (http://www.facebook.com/sharer/sharer.php?u=) and wanting to monitor when the user clicks "Share Link" so that I can close the web view.
Thank you all for your time!
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WendiKidd over 12 yearsI implemented that function and the method gets called when webpages are being loaded. Unfortunately, it is not called when the button is clicked.
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WendiKidd over 12 yearsOh, I'm sorry, I'm a bit new to this and I was trying to use "enter" to go down to a new line but it submitted the comment before I was ready. Sorry! To continue, perhaps it would help if I gave a bit more information about the button I am trying to receive events for. I am attempting to allow the user to compose a facebook wallpost. I am opening up the facebook sharer page (facebook.com/sharer/sharer.php?u=) and then wanting to monitor when the "Share Link" button is pressed so I can close the webview. Otherwise it appears as if nothing happened even when the wallpost is made