I have a UIViewController which is a UIWebViewDelegate and has a UIWebView inside of it. I am trying to load a particular URL
NSURL *url = [NSURL URLWithString:urlAddress];
NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];
[webView loadRequest:requestObj];
[self.view addSubview:webView];
[webView release];
But the didFailLoadWithErrordelegate method is almost instantly called, and the error object is:
Did fail load with error: Error Domain=NSURLErrorDomain Code=-999 "The operation couldn’t be completed. (NSURLErrorDomain error -999.)" UserInfo=0x1a66c0 {NSErrorFailingURLKey=www.somewebsite.com, NSErrorFailingURLStringKey=www.somewebsite.com}
However a short time after, you can see that the website loads just fine.
Why is the fail method being called? And how do I know when it has actually failed versus when the method was called regardless of if the website actually failed or not?
You can get this error when the page is instantly redirected via javascript or somehow else
You can avoid showing the error by answer from here: How do I fix NSURLErrorDomain error -999 in iPhone 3.0 OS
like
if ([error code] != NSURLErrorCancelled) { //show error alert, etc. }
but I don't know how to recognize where it was invoked.
So according to another StackOverflow question from a while back, the error code you're getting is being caused by a request being made before the previous request has been completed.
What may be happening is you are making multiple calls at the same time / very rapidly, and one is succeeding (so your web page loads) but the other is failing.
Use TapGesture on the web view using tapcount of 1.
Using a function for handling TapGesture, check if the URL returns status code of 200, if so, call the below function
-(void)animateme{
NSString *urlAddress = Connecting_URL
NSURL *url = [NSURL URLWithString:urlAddress];
NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];
[self.webview loadRequest:requestObj];
}
And, using delegate function,
-(void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Device in offline" message:#"Please check your internet connection" delegate:nil cancelButtonTitle:nil otherButtonTitles:nil];
[alert show];
}
Hope it helps :)
Related
I've been looking around, saw similar posts, but nothing like this that could give me answers. This is my setup and flow of the app:
User has to login via Facebook, using Facebook Graph. LoginView is presented modally, non animated
When user logins I can retrieve FBID and I use this fbid to send it to my web service (REST)
Web service gets the FBID from the NSURL and matches it with database to retrieve other user info
Using JSONserialization i parse the JSON received from web service and display it in the view
PROBLEM: Everything returns NULL except FBID that I get from Facebook. BUT, if I logout from Facebook and then login, that's when it works.
Here is my code:
viewDidAppear method:
-(void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:NO];
if (FBSession.activeSession.isOpen) {
[self populateUserDetails];
}
//Connect to WebService
NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:#"http://atnightcorp.com/api/member/id/%#/format/json", fbid]];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
[NSURLConnection connectionWithRequest:request delegate:self];
NSArray *pics = [member valueForKeyPath:#"photos"];
NSString *picCount = [NSString stringWithFormat:#"%d", [pics count]];
[photosCount setTitle:picCount forState:UIControlStateNormal];
NSLog(#"PHOTO: %#", picCount);
NSLog(#"FB: %#", fbid);
}
I tried putting NSURL request and connection code in viewDidLoad, but then I don't get anything back.
My NSURLConnection methods:
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
data = [[NSMutableData alloc]init];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)theData
{
[data appendData:theData];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
member = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
UIAlertView *errorView = [[UIAlertView alloc]initWithTitle:#"Error" message:#"The download could not complete. Please make sure you are connected to internet" delegate:nil cancelButtonTitle:#"Dismiss" otherButtonTitles:nil];
[errorView show];
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
}
The populateUserDetails method that you have seen above:
- (void)populateUserDetails
{
if (FBSession.activeSession.isOpen) {
[[FBRequest requestForMe] startWithCompletionHandler:
^(FBRequestConnection *connection,
NSDictionary<FBGraphUser> *user,
NSError *error) {
if (!error) {
self.userProfileImage.profileID = user.id;
self.navigationItem.title = user.name;
self.fbid = user.id;
}
}];
}
}
This method basically sets the FBID once user is logged in. Other important things you should know that could help you understand my project:
FBID is set as NSString property in my .H file
All facebook connect thing goes on in AppDelegate
I need to dynamically set the NSURL after I find out who the user is.
if I manually input FBID in NSURL, then it works.
everything should be executed when user logins, I think that the timing of retrieving fbid and receiving data from web service is wrong but I can't get to fix it.
IF you need anything else, I will elaborate more and post more code if needed. -
PLEASE HELP as I've been looking for answers for last 3 days.
Your problem is that the populateUserDetails is called and it returns without waiting the code to be executed (because it's an async task with a completition handler, and when you call the NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:#"http://atnightcorp.com/api/member/id/%#/format/json", fbid]]; for the first time, the fbid is nuil or not set properly (also you should use self.fbid not fbid since fbid is a property).
So you should try to move the whole code that is handling the request from viewDidAppear into a separate method and you should call that method from startWithCompletionHandler after you set the line with self.fbid = user.id
Also call [super viewDidAppear:animated]; not with NO param (this won't solve your problem but this is the right way to do it)
First of all the questions are failry simiple.. if you just want to see what they are skip to the bottom of this post and you will see them in bold.. for more detail then you can read the rest of this post...
I am just trying to iron out my NSURLConnection so that its working smoothly and I understand this properly. There is a profound lack of example/tutorials for Asynchronous connections on the internet or not any that I can find that explaine what is going on with any level of depth other than getting the connection up and running which after working on it seems pretty simple. Hopefully this question can full the void that I feel is out there for other users.
So, in my .h file i have imported the foundations headers and declared the methods required for the received or lack of received data (errors etc).
.h
#import <UIKit/UIKit.h>
#import <Foundation/Foundation.h> //add foundations
//.. other headers can be imported here
#interface MyViewController: UITableViewController {
//Im not setting any delegates to access the methods because Is all happening in the same
//place so I just use the key word 'self' when accessing the methods declared below
//I'm not sure if this is the best thing to do but I wasn't able to get my head around declaring the delegate or how it would help me with the way I have set up my request etc.
}
- (IBAction)setRequestString:(NSString *)string; //this method sets the request and connection methods
//these methods receive the response from my async nsurlconnection
- (void)receivedData:(NSData *)data;
- (void)emptyReply;
- (void)timedOut;
- (void)downloadError:(NSError *)error;
So thats my header file.. pretty simple not much explaining needed.
.m
//call setRequestString from some other method attached to a button click or something
[self setRequestString:#"rss.xml"];
//..
- (IBAction)setRequestString:(NSString *)string
{
//Set database address
NSMutableString *databaseURL = [[NSMutableString alloc] initWithString:#"http:www.comicbookresources/feeds/"]; // address not real jsut example
//append the string coming in to the end of the databaseURL
[databaseURL appendString:string];
//prepare NSURL with newly created string
NSURL *url = [NSURL URLWithString:databaseURL];
//AsynchronousRequest to grab the data
NSURLRequest *request = [NSURLRequest requestWithURL:url];
NSOperationQueue *queue = [[NSOperationQueue alloc] init];
[NSURLConnection sendAsynchronousRequest:request queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *error)
{
if ([data length] > 0 && error == nil){
[self receivedData:data];
}else if ([data length] == 0 && error == nil){
[self emptyReply];
}else if (error != nil && error.code == NSURLErrorTimedOut){ //used this NSURLErrorTimedOut from foundation error responses
[self timedOut];
}else if (error != nil){
[self downloadError:error];
}
}];
}
now set up the methods that were initialized in the .h file and called in the if statement above
- (void)receivedData:(NSData *)data
{
NSString* newStr = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(#"%#", newStr); //logs recived data
//now you can see what data is coming in on your log
//do what you want with your data here (i.e. start parsing methods
}
- (void)emptyReply
{
//not sure what to do here yet?
}
- (void)timedOut
{
//also not sure what to do here yet?
}
- (void)downloadError:(NSError *)error
{
NSLog(#"%#", error);
UIAlertView *errorAlert = [[UIAlertView alloc] initWithTitle:#"Error!" message:#"A connection failure occurred." delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil, nil];
[errorAlert show];
}
Cool so that pretty much the basics of what I have done right there.. now the questions I have are as follows.
Question one:
Where I call NSURLConnection like so
[NSURLConnection sendAsynchronousRequest:request queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *error)
{
What is happening here what is the ^ for is that executing that whole block (including the if statements) on a different thread or something? because it looks alot like grand central dispatch formatting but slightly different.
Question two:
what should I be doing inside emptyReply & timedOut methods?
Question three:
How would I incorporate caching into this? I would like to cache the responses I get back from different requests. i.e. with my setRequestString you will see there is a string input parameter, so i can request different rss feeds with the same method.. I need to figure out how to cache these responses into individual caches.. but im not sure where to start with it.
Finally
If you have made it this far, thank you very much for reading my question. Hopefully with your responses we can get a pretty nice solution going here.. that other people can use for themselves and pick and choose the bits and peices they need that works for there own solution..
Anyway thank you very much for reading and I look forward to your replies.. even if they are just refrences to tutorials or examples you think might help me.. anything is good I just want to fully understand whats going on and whats a good solution.
Read about blocks in Apple documentation. Its new. Or you can read here
You can show errors such as request timed out etc. You don't really have to handle them separately than the error one unless you have special logic.
Try this for caching
NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData timeoutInterval:TIMEOUT_INTERVAL];
I'm debugging a crash reported as:
Exception Type: SIGSEGV
Exception Codes: SEGV_ACCERR
The crash is happening on the line that does numberOfFails++.
The app uses ASIHTTP. I personally much prefer using NSURLConnection. I'd never automatically repeat a request for NSURLConnection if it failed because I've never seen it fail when it shouldn't. I'd rather just give the UI a refresh button or show a UIAlertView with a button to try again or something like that.
Anyway, to cooperate with other team members, I'm looking to fix this issue without replacing ASIHTTP with NSURLConnection for now.
The request is being started with something like:
- (void)getResources:(CLLocation *)location withQuery:(NSString *)query {
NSURL *url = [NSURL URLWithString:[NSString stringWithString:#"https://example.com/"]];
self.resourcesAPIRequest = [ASIFormDataRequest requestWithURL:url];
[resourcesAPIRequest setPostValue:[Model instance].oauth_token forKey:#"oauth_token"];
[resourcesAPIRequest setPostValue:[[NSNumber numberWithDouble:location.coordinate.latitude] stringValue] forKey:#"latitude"];
[resourcesAPIRequest setPostValue:[[NSNumber numberWithDouble:location.coordinate.longitude] stringValue] forKey:#"longitude"];
[resourcesAPIRequest setPostValue:query forKey:#"query"];
[resourcesAPIRequest setDelegate:self];
[resourcesAPIRequest setDidFinishSelector:#selector(resourcesAPIReturned:)];
resourcesAPIRequest.userInfo = [NSDictionary dictionaryWithObjectsAndKeys:NSStringFromSelector(#selector(getResources:withQuery:)), #"repeatSelector", location, #"argument1", query, #"argument2", nil];
[resourcesAPIRequest startAsynchronous];
}
One thing I noticed is : <ASIHTTPRequestDelegate> is not in the header file, but this callback method is still being called OK:
#define maximumNumberOfFails 50
- (void)requestFailed:(ASIFormDataRequest *)request {
static int numberOfFails = 0;
if (numberOfFails < maximumNumberOfFails) {
[NSThread sleepForTimeInterval:sleepTimeInSeconds];
if ([request.userInfo objectForKey:#"argument2"]) {
[self performSelector:NSSelectorFromString([request.userInfo objectForKey:#"repeatSelector"]) withObject:[request.userInfo objectForKey:#"argument1"] withObject:[request.userInfo objectForKey:#"argument2"]];
} else if ([request.userInfo objectForKey:#"argument1"]) {
[self performSelector:NSSelectorFromString([request.userInfo objectForKey:#"repeatSelector"]) withObject:[request.userInfo objectForKey:#"argument1"]];
} else {
[self performSelector:NSSelectorFromString([request.userInfo objectForKey:#"repeatSelector"])];
}
numberOfFails++;
} else {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Problem" message:#"There was a problem connecting to the servers. Please make sure you have an Internet connection." delegate:nil cancelButtonTitle:#"Ok" otherButtonTitles:nil];
[alert show];
[alert release];
numberOfFails = 0;
}
}
Also, I think that static int numberOfFails should be static NSUInteger numberOfFails. And, I noticed that the request is started with startAsynchronous. Is static int numberOfFails atomic? That may be why we're getting the error SEGV_ACCERR (Invalid permissions for mapped object).
Thoughts?
The problem likely has nothing to do with your static variable.
Does requestFailed: execute on the main thread, or in a background thread?
If it's on a background thread, you'll need to use performSelectorOnMainThread:withObject:.
If it's on the main thread, you may need to take a pass through the runloop before executing a new HTTP request. To do that, use performSelector:withObject:afterDelay:, and pass '0.0' as the delay.
You'll notice that both those methods allow only a single method parameter. Typically, you pass your parameters in a NSDictionary rather than try to parse out the number of parameters beforehand, like you're doing.
Guys, I was retrieving an XML response from a .php script on my server using the following code:
NSString *xmlString = [NSString stringWithContentsOfURL:[NSURL URLWithString:urlString]
encoding:NSUTF8StringEncoding error:&error];
and
//tried also: if(error)
if(!xmlString)
{
NSString * errorString = [NSString stringWithFormat:#"Unable to download xml data (Error code %i )", [error code]];
UIAlertView * errorAlert = [[UIAlertView alloc] initWithTitle:#"Error loading content" message:errorString delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil];
[errorAlert show];
[errorAlert release];
}
//*** now I have a touchXML xPath query code that extracts what I need from XML
My .php script wasn't working today and my iApp was freezing without any alerts, errors or notifications? I thought that the code above will handle errors but it doesn't???
A) Then what type of error does it catch?
Then I remembered that i I should try working with NSURLConnection and its delegate methods to catch any error that occurs.
//Inside viewDidLoad method
NSMutableData *responseData = [[NSMutableData alloc] init];
NSURL *baseURL = [[NSURL URLWithString:self.chosenDrawRss] retain];
NSURLRequest *request = [NSURLRequest requestWithURL:baseURL];
[[[NSURLConnection alloc] initWithRequest:request delegate:self] autorelease];
NSString *xmlString = [[NSString alloc] initWithData:self.responseData encoding:NSUTF8StringEncoding];
The problem I had using this approach was that app ran the Connection in the background and continued executing the rest of the code found in viewDidLoad, so I had to reorganize my code a bit by moving it to another method that I call from delegate method connectionDidFinishLoading. The problem I have is that my delegate methods are not called. Well, all except didFailWithError: if I try to load URL that doesn't exist.
UPDATE:
delegate methods are called but it takes one minute or so for delegate method to be called and until alert message pops out...
B) Could I use stringWithContentsOfURL and still have an alert to the user if anything happens?
C) If not, then I need help with setting up NSURLConnection approach? I mean, what I'm missing here is why aren't my delegate methods called?
I truly hope my questions make sense :D
L
If your delegate method is called in didFailWithError then i suppose it will even be called in
connectionDidFinishLoading. Check by enabling a breakpoint in the delegate methods and track the flow. It may have happened the function returns before you call the delegate.
NSString *xmlString = [[NSString alloc] initWithData:self.responseData encoding:NSUTF8StringEncoding]
should be called in your delegate connectionDidFinishLoading method and in
- (void) connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
[responseData appendData:data];
}
I dont see why the alert should pop up after a minute unless you are doing some processing before displaying it.
I'm trying this:
ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:
[NSURL URLWithString:my_url]];
[request setPostValue:id_ forKey:#"id_source"];
[request setPostValue:email forKey:#"email"];
[request startSynchronous];
And I got from console
wait_fences: failed to receive reply: 10004003
Which is something internal.
Do you have idea why? I'm trying the form for real, from browser, and it works with no problems. Don't have error in the URL, or in any parameter.
To debug the request, try getting the `response in this way:
NSError *error = [request error];
if (!error) {
NSString *response = [request responseString];
}
error should tell you everything you need to know, and should shield your response from any problems. Here's a good post on NSError, if you haven't done this before.
About the existing wait_fences thing... I think I've got this one figured out, based on some other sources listed below.
it looks like this issue comes about when an input field fails to resign its firstResponder status. My long shot guess is that the keyboard that's helping you populate the form you're processing isn't resigning its status as firstResponder.
so, in your view controller, assuming you've got a text field declared, you might try this:
- (void)viewDidLoad
{
// set up the text field
[self.textField setDelegate:self];
[self.textField addTarget:self
action:#selector(textFieldFinished:)
forControlEvents:UIControlEventEditingDidEndOnExit];
[super viewDidLoad];
}
- (IBAction)textFieldFinished:(id)sender
{
[sender resignFirstResponder];
}
Some posts I looked at to form this opinion:
"wait_fences: failed to receive reply: 10004003"?
http://www.iphonedevsdk.com/forum/iphone-sdk-development-advanced-discussion/17373-wait_fences-failed-receive-reply-10004003-a.html
http://discussions.apple.com/thread.jspa?threadID=2014220