I have a simple method that takes a url and loads it from the server:
- (void)loadURL:(NSString*)url
{
NSMutableURLRequest* request = [[NSMutableURLRequest alloc] init];
request.HTTPMethod = #"GET";
request.URL = [NSURL URLWithString:url];
NSHTTPURLResponse* response;
[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:nil];
}
The server returns a response with max-age of 1 day.
Problem is that when I run these 3 lines repeatedly, 2 of them randomly miss the cache and reload the response:
[self loadURL:#"http://192.168.0.105:8080/users/51bdbc73808897302f000001/avatar?size=200x200&access_token=abcdefghijklmnopqrstuvwxyzzp77eDLqub3EWfXGe4c09RoyipmXgcENwfE6EV9yzvgp5VTSZww"];
[self loadURL:#"http://192.168.0.105:8080/users/51ee9d4e263d08fe04000003/avatar?size=200x200&access_token=abcdefghijklmnopqrstuvwxyzzp77eDLqub3EWfXGe4c09RoyipmXgcENwfE6EV9yzvgp5VTSZww"];
[self loadURL:#"http://192.168.0.105:8080/users/51d17b81de38c60b20000006/avatar?size=200x200&access_token=abcdefghijklmnopqrstuvwxyzzp77eDLqub3EWfXGe4c09RoyipmXgcENwfE6EV9yzvgp5VTSZww"];
If I add some random unique data (&x, &y, &z) to each request's query string it fixes the problem:
[self loadURL:#"http://192.168.0.105:8080/users/51bdbc73808897302f000001/avatar?size=200x200&access_token=abcdefghijklmnopqrstuvwxyzzp77eDLqub3EWfXGe4c09RoyipmXgcENwfE6EV9yzvgp5VTSZww&x"];
[self loadURL:#"http://192.168.0.105:8080/users/51ee9d4e263d08fe04000003/avatar?size=200x200&access_token=abcdefghijklmnopqrstuvwxyzzp77eDLqub3EWfXGe4c09RoyipmXgcENwfE6EV9yzvgp5VTSZww&y"];
[self loadURL:#"http://192.168.0.105:8080/users/51d17b81de38c60b20000006/avatar?size=200x200&access_token=abcdefghijklmnopqrstuvwxyzzp77eDLqub3EWfXGe4c09RoyipmXgcENwfE6EV9yzvgp5VTSZww&z"];
Also, if I reduce the length of query strings to 80 chars it fixes the problem as well:
[self loadURL:#"http://192.168.0.105:8080/users/51bdbc73808897302f000001/avatar?size=200x200&access_token=abcdefghijklmnopqrstuvwxyzzp77eDLqub3EWfXGe4c09Royipm"];
[self loadURL:#"http://192.168.0.105:8080/users/51ee9d4e263d08fe04000003/avatar?size=200x200&access_token=abcdefghijklmnopqrstuvwxyzzp77eDLqub3EWfXGe4c09Royipm"];
[self loadURL:#"http://192.168.0.105:8080/users/51d17b81de38c60b20000006/avatar?size=200x200&access_token=abcdefghijklmnopqrstuvwxyzzp77eDLqub3EWfXGe4c09Royipm"];
What's going on?
Is this a bug in iOS? How can I fix it?
P.S: I've tested this in an empty application with no extra stuff both on iOS 5 and 6.
Set the caching behaviour in the NSURLRequest with requestWithURL:cachePolicy:timeoutInterval:. Try:
- (void)loadURL:(NSString*)url
{
NSURL *url = [NSURL URLWithString:url];
NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy: NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:10.0];
NSHTTPURLResponse* response;
[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:nil];
}
Possibly also use NSURLRequestReloadIgnoringLocalAndRemoteCacheData for cachePolicy.
you might want to use ASIHTTPRequest instead
http://allseeing-i.com/ASIHTTPRequest/
Related
Actually I want to created application of shortening URL , i have used GoDady by creating account at http://app.x.co/ But My URL doesnot get shorten.
This is my key
#define kGoDaddyAccountKey #"b201137c009311e6984efa163ee12fa9"
This is actually The method that do work for Shortening URL
- (IBAction)shortenURL:(id)sender
{
NSString *urlToShorten = self.webView.request.URL.absoluteString;
NSString *urlString = [NSString stringWithFormat:#"http://api.x.co/Squeeze.svc/text/%#?url=%#",kGoDaddyAccountKey,
[urlToShorten stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
shortURLData = [NSMutableData new];
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:urlString]];
shortenURLConnection = [NSURLConnection connectionWithRequest:request
delegate:self];
}
But I get error like This.
Quite Interesting, Please Help.
I am using the following code to make sure that if the URL is available:
NSString *const URL = #"http://some_url/";
-(BOOL) isURLReachable
{
NSHTTPURLResponse *response;
NSError *error = nil;
NSURL *url = [NSURL URLWithString:URL];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
[NSURLConnection sendSynchronousRequest:request returningResponse:&response
error:&error];
// just for testing
NSLog(#"checking response!");
return [response statusCode] == 200;
}
I can only reach the url when I am connected to the company's network which is okay. But when I go outside or on my 4G network I still get status code 200. Further investigation revealed that if the URL is not available then Tmobile searches for the URL and displays in a search view and returns status code 200. I do not want that? If the URL is not reachable then I would like to know that it is not reachable. How can I proceed?
This is the logical flow for my application:
At first, when the view controller has finished loading, then a NSURLConnection request can start its execution
The response consists in xml data
After parsing that xml I need to send another NSURLConnection request.
After sending the second request, if the response is ok, I receive other xml data
After parsing the second xml, I have to check some issues between first and second xml data.
So, is it possible to send multiple request? How? I do not need code, you could just explain it.
Thank you in advance.
I do this with the NSURLConnection Making them properties, then checking which one it is:
#property (nonatomic,retain) NSURLConnection *myConnection;
#property (nonatomic,retain) NSURLConnection *mySecondConnection;
then in the delegate:
- (void)connectionDidFinishLoading:(NSURLConnection *)connection{
if (connection == myConnection){
//do something
}
if (connection == mySecondConnection){
// do something else
}
}
You can pass your NSURLRequest to the connection:
self.myConnection=[[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
There is a third party library available which is a wrapper on CFNetwork is ASIHTTPREQUEST
This Library should do work for you. so that you don't have to write the code from scratch. other alternative is create one class which will be responsible for creating NSURLConnection then sending the request and finally notify to view controller using delegate or notification one data is received .
- (void)viedDidLoad{
[super viewDidLoad];
[self firstRequestMethod];
}
- (void)firstRequestMethod{
NSString *myFirstRequestURL = #"<URL>";
NSURL *webURL = [NSURL URLWithString:myFirstRequestURL];
NSURLRequest *request = [NSURLRequest requestWithURL:webURL cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
NSError *error;
NSURLResponse *response;
NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
if(returnData)
{
NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSASCIIStringEncoding];
//Parse your response here.
//Is desired response obtain call the second Request, as described above
if (TRUE) { //on success
[self secondRequestMethod];
}
}
}
- (void)secondRequestMethod{
NSString *mySecondRequestURL = #"<URL>";
NSURL *webURL = [NSURL URLWithString:mySecondRequestURL];
NSURLRequest *request = [NSURLRequest requestWithURL:webURL cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
NSError *error;
NSURLResponse *response;
NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
if(returnData)
{
NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSASCIIStringEncoding];
//Parse your response here.
//Is desired response obtain call the second Request, as described above
if (TRUE) { //on success
//subsequent calls to other url, same as above
}
}
}
Hope this will help you understand better....
I am aware of discussions regarding nsurlconnection on ios, and that there is a minimum of 240 seconds for a timeout. My question is, if I am sending a synchronous call via NSURLConnection's + (NSData *)sendSynchronousRequest:(NSURLRequest )request returningResponse:(NSURLResponse *)response error:(NSError **)error, is there any chance I can cancel this before the 240 seconds is up? I am thinking perhaps setting a timer to cancel this synchronous request, but im not even sure if its even possible? Im thinking:
[self performSelector:#selector(cancelRequest:) withObject:myRequest afterDelay:myTimeOut];
I have a feeling this will result in disaster if somehow the request has been released, and I would have no way to determine that. Thoughts? Has anyone tried to do this? This is a synchronous call.
You cannot cancel it. Simply don't use it and use an asynchronous call instead. Those you can easily cancel.
This seemed to work for me:
NSURL *url = [NSURL URLWithString:#"http://someurl.com"];
NSURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:5];
NSHTTPURLResponse *response = nil;
[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:NULL];
if (response == nil) {
// timed out or failed
} else {
// all good
}
Ofcourse setting the timeout interval to how long you want it to block the main thread before timing out - The above code successfully timed out after 5 seconds
Tested in iOS6 & iOS5.1
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringCacheData timeoutInterval:10.0];
webData = (NSMutableData *)[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&err];
if (webData==nil) {
[self displayAlert:#"Time Out" message:#"Request Timed Out"];
}
Timeout in exactly 10 seconds.
I have URL like this: http://example.com/image.jpg
What the simplest way to save url's target content into the local file on the iOS (iPhone)?
One of the simplest way is the following:
NSURL *url = [NSURL URLWithString:..];
NSData *data = [NSData dataWithContentsOfURL:url];
NSString *fileName = ..
[data writeToFile:fileName atomically:NO];
A simple way to do this would be to use the ASIHTTPRequest project. Primarily because it already has the required reachability checks built in and it is easy to setup and use asynchronous request.
Asynchronous download example from the site:
- (IBAction)grabURLInBackground:(id)sender
{
NSURL *url = [NSURL URLWithString:#"http://allseeing-i.com"];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
[request setDelegate:self];
[request startAsynchronous];
}
- (void)requestFinished:(ASIHTTPRequest *)request
{
// Use when fetching binary data
NSData *responseData = [request responseData];
}
Reachability comment from the site:
It allows ASIHTTPRequest to be
notified when the network connection
changes from WWAN to WiFi, or
vice-versa.