I'm trying to show upload progress in UIAlertView. I have an API with my server subclass of AFHTTPClient and some code where I send progress info to my view
[operation setUploadProgressBlock:^(NSInteger bytesWritten,long long totalBytesWritten,long long totalBytesExpectedToWrite)
{
float progress = totalBytesWritten / (float)totalBytesExpectedToWrite;
request *svc = [[request alloc] init];
[svc setProgress:[NSNumber numberWithFloat:progress]];
NSLog(#"Sent %lld of %lld bytes", totalBytesWritten, totalBytesExpectedToWrite);
}];
When uploading process starts I create UIAlertView in my View
API file
if (uploadFile) {
[formData appendPartWithFileData:uploadFile name:#"file" fileName:#"photo.jpg" mimeType:#"image/jpeg"];
request *svcAlert = [[request alloc] init];
[svcAlert showProgressAlert];
}
View file
- (void) showProgressAlert{
progressBarAlert = [[UIAlertView alloc] initWithTitle: #"Идет загрузка"
message: #"0"
delegate: self
cancelButtonTitle: nil
otherButtonTitles: nil];
progressView = [[UIProgressView alloc] initWithProgressViewStyle: UIProgressViewStyleBar];
progressView.frame = CGRectMake (20, 20, 50, 30);
[progressBarAlert addSubview:progressView];
[progressBarAlert show];
}
Then in my View I'm also trying to change UIAlertView message parameter with setMessage but nothing happens. ProgressView doesn't show up in AlertView even thought I'm adding it with addSubview.
-(void) setProgress: (NSNumber *) progress {
progressView.progress = [progress floatValue];
//progressBarAlert.message = [NSString stringWithFormat:#"%#", progress];
[progressBarAlert setMessage:[NSMutableString stringWithFormat:#"Загрузка %#", progress]];
}
And the last question, how do I close UIAlertView without pressing cancel button?
Also I've tried to add subView to my view instead of using alertView, but app crashed with uncaught exception. Maybe someone could give me any advice about this task.
I will refer you to the Apple Documentation in regards to UIAlertView Class reference and specifically
The UIAlertView class is intended to be used as-is and does not support subclassing. The view hierarchy for this class is private and must not be modified.
What you are trying to do by doing [progressBarAlert addSubview:progressView]; isn't allowed and will get your app rejected from the Apple review process. In iOS7 addSubview: never calls the super on UIView so doesn't actually do anything. So I wouldn't recommend doing this at all. There are however custom alert views like https://github.com/wimagguc/ios-custom-alertview that you can use to get what you are after.
Related
Don't know what to do with it. but i loaded data and load table when data is loaded,
[manager POST:path parameters:parameters success:^(NSURLSessionDataTask *task, id responseObject) {
arryGlobal = [NSMutableArray new];
[arryGlobal addObject:responseObject];
if([[[[arryGlobal valueForKey:#"Success"] objectAtIndex:0] stringValue] isEqualToString:#"1"]){
arryGlobal = [[arryGlobal valueForKey:#"Result"] objectAtIndex:0];
dispatch_async(dispatch_get_main_queue(), ^{
[self.tblMainCategory reloadData];
});
}
else if([[[[arryGlobal valueForKey:#"Success"] objectAtIndex:0] stringValue] isEqualToString:#"0"]){
}
} failure:^(NSURLSessionDataTask *task, NSError *error) {
//here is place for code executed in error case
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"Error while sending"
message:#"Sorry, try again."
delegate:nil
cancelButtonTitle:#"Ok"
otherButtonTitles:nil];
[alertView show];
NSLog(#"Error: %#", [error localizedDescription]);
}];
It works perfectly two times, but when i go for 3rd time call this webservice it load data, get data, table successfully reloaded, but it not change content in table, it appear as it is in 2nd time.
SO what happens there ?? When I scroll table, then in cellForRowAtIndexPath array that i use to pass in table is contain data of 2nd time called Webservice.
EDIT:
i added this table view VievController in other view like :
MainCategory *objMain = [[MainCategory alloc] initWithNibName:#"MainCategory" bundle:nil];
[objMain LoadData:tag];
objMain.view.frame = CGRectMake(0, 0, self.bgViewCat.frame.size.width, self.bgViewCat.frame.size.height);
[self.bgViewCat insertSubview:objMain.view atIndex:1];
[self addChildViewController:objMain];
[objMain didMoveToParentViewController:self];
Try This
if([[[[arryGlobal valueForKey:#"Success"] objectAtIndex:0] stringValue] isEqualToString:#"1"])
{
[arryGlobal removeAllObjects];
arryGlobal=[NSarray alloc]init];
arryGlobal = [[arryGlobal valueForKey:#"Result"] objectAtIndex:0];
dispatch_async(dispatch_get_main_queue(), ^{
[self.tblMainCategory reloadData];
});
}
the block:success() already run in main queue;you needn't use dispatch_async(dispatch_get_main_queue();
and arryGlobal is a kind of NSMutableArray;why you use the function called "thevalueforKey:" to get the value ?
I think maybe you should print the responseObject to check your data
ok so ther's error on :
[self.bgViewCat insertSubview:objMain.view atIndex:1];
Instead of this I use this and everything is fine, don't know why?:
[self.bgViewCat addSubview:objMain.view];
In my modal UI there is a "DONE" button linked with IBAction -done:, it will upload a text to (lets say Dropbox server). Its code looks like this
- (IBAction)done:(id)sender {
// must contain text in textview
[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
if (![_textView.text isEqualToString:#""]) {
// check to see if we are adding a new note
if (!self.note) {
DBFile *newNote = [[DBFile alloc] init];
newNote.root = #"dropbox";
self.note = newNote;
}
_note.contents = _textView.text;
_note.path = _filename.text;
// - UPLOAD FILE TO DROPBOX - //
NSLog(#"Initializing URL...");
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0), ^{
NSURL *url = [Dropbox uploadURLForPath:self.note.path];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];
[request setHTTPMethod:#"PUT"];
NSData *noteContents = [self.note.contents dataUsingEncoding:NSUTF8StringEncoding];
NSLog(#"Creating session task...");
NSURLSessionUploadTask *uploadTask = [self.session uploadTaskWithRequest:request
fromData:noteContents
completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
NSHTTPURLResponse *resp = (NSHTTPURLResponse *) response;
if (!error && resp.statusCode == 200) {
NSLog(#"OK");
dispatch_async(dispatch_get_main_queue(), ^{
[self.delegate noteDetailsViewControllerDoneWithDetails:self];
});
} else {
NSLog(#"Status code: %d", resp.statusCode);
}
}];
[uploadTask resume];
});
} else {
UIAlertView *noTextAlert = [[UIAlertView alloc] initWithTitle:#"No text"
message:#"Need to enter text"
delegate:nil
cancelButtonTitle:#"Ok"
otherButtonTitles:nil];
[noTextAlert show];
}
}
The delegate method noteDetailsViewControllerDoneWithDetails: of this class is look like this
-(void)noteDetailsViewControllerDoneWithDetails:(NoteDetailsViewController *)controller{
// refresh to get latest
[self dismissViewControllerAnimated:YES completion:nil];
[self notesOnDropbox];}
(notesOnDropbox is a time-consuming task). When DONE button is tapped, I expect this modal VC/UI to dismiss immediately and it fetches data on background (by notesOnDropbox method). However, when I try tapping DONE button, my UI stop responding for about seconds, after that the modal UI is dismissed. I cannot figure out where I misuse the GCD. Please help me.
if you want to dismiss your modal VC/UI immediately, just ask the delegate to dismiss,
like is:
- (IBAction)done:(id)sender {
[self.delegate noteDetailsViewControllerDoneWithDetails:self];
// ...
}
In your sample code,
you do the dismiss action after the upload task completed, but the upload task is asynchronous.
and you ask the delegate to dismiss use GCD dispatch_async, this is asynchronous task, too.
After all, you have to consider the what time to do upload, who to do upload task and what time to invoke notesOnDropbox.
First, if notesOnDropbox is a time-consuming task, then you should not be performing it on the main thread (as you are doing). If it is sufficiently time-consuming and you do it on the main thread, the WatchDog process will kill your app dead right before the user's eyes.
Second, there is no need to get off the main thread to do an upload. If you use NSURLSession correctly, it will be asynchronous.
Your code only calls noteDetailsViewControllerDoneWithDetails when the whole upload task is completed, because that's how you wrote your code. Actually, the situation seems worse. If the upload task has any kinds of problems, noteDetailsViewControllerDoneWithDetails will never be called.
You need to call noteDetailsViewControllerDoneWithDetails as soon as possible, and then think about what you are going to do when the upload fails - which might easily happen a long time later.
I m very new to iOS, as stated in the question above; im trying to do these 3 simple step.
Show Alert view
Do parsing stuff
Dismiss Alert
I was looking for something like we have in android i.e Pre Execute, doInBackground and Post Execute().
This is what i have tried.
parserAlert = [[UIAlertView alloc] initWithTitle:#"Loading" message:#"Please Wait" delegate:nil cancelButtonTitle:#"Ok" otherButtonTitles:nil, nil];
[parserAlert show];
dispatch_queue_t queue = dispatch_queue_create("com.abc.testing", DISPATCH_QUEUE_SERIAL);
dispatch_sync(queue,^{
DBHandler *myDB= [[DBHandler alloc] init];
[myDB fetchResults];
dispatch_async(dispatch_get_main_queue(),^{
[parserAlert dismissWithClickedButtonIndex:0 animated:YES];
});
});
Below is the fetchResult method.
- (void) fetchResults
{
IParser *i = [[IParser alloc] init];
[i startParse];
AGParser *ag = [[AGParser alloc] init];
[ag startParse];
GParser *g = [[GParser alloc] init];
[g startParse];
HParser *h = [[HParser alloc] init];
[h startParse];
SParser *s = [[SParser alloc] init];
[s startParse];
}
This is startParse.
NSString *url = #"http://abcd.com/Service_URL/Service.asmx/GetNotes";
NSURL *nsUrl = [[NSURL alloc] initWithString:url];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL:nsUrl];
NSURLConnection *con = [[NSURLConnection alloc] initWithRequest:request delegate:self];
responseData = [[NSMutableData alloc] init];
[con start];
When i run the above code, Alerview show and dismiss within a second. Adding logs on methods i observed that fetchresults method return immediately and alert view gets dismiss. However fetchResults associated threads(Connection methods, Parser methods) keep executing but alerview is dismissed.
I need a guideline how to block the code until all associated methods are finished.
Thanks for your time.
I know this is not the answer you want, but don't use an alert view for this. A nice way to cover for time-consuming activity to is to put up a UIActivityIndicatorView, or a view that contains one, and set it spinning:
http://www.apeth.com/iOSBook/ch25.html#_uiactivityindicatorview
You can also prevent user interaction while the time-consuming activity is happening, with the shared application object's beginIgnoring... (and turn that off with endIgnoring... when you're done). Obviously you can't do that, though, if the user is to be given a Cancel button. In that case, cover everything else with an invisible view (clear background color) whose userInteractionEnabled is YES, so that it eats any touches intended for anything other than the button.
Also, it is almost never the right answer to use dispatch_sync. Once you've frozen the interface in the way I've just described, you can just do your connections (asynchronous) and parsing (on a background thread) and then come back into the main thread to dismiss the activity indicator.
Finally, you're going to want to leave yourself a way out in case things go wrong. You could run an NSTimer, for example.
EDIT: And now for the actual answer to your actual question, i.e. why is my code not pausing even though I used dispatch_sync: it's because [[NSURLConnection alloc] initWithRequest:request delegate:self] returns immediately; the networking is in yet another background thread. So your startParse returns, your fetchResults returns, and meanwhile the networking continues and the NSURLConnection delegate methods are called some time later.
Here is the link what you are looking for MBProgressHUD
First alloc the MBProgressHUD instance of it in the viewDidLoad
MBProgressHUD *progressHUD = [[MBProgressHUD alloc] initWithView:self.view];
progress.delegate=self;
[progressHUD showWhileExecuting:#selector(performBackgroundTask) onTarget:self withObject:nil animated:YES]
and in the background method
-(void)performBackgroundTask
{
//Do some stuff
}
and soon as the task in the )performBackgroundTaskmethod is completed the Activity indicator shown in the MBProgressHUD will hidden and the delegate method called
-(void)hudWasHidden
{
//Do additional stuff after completion of background task
}
Hope it will help you.
I want to start a task that runs on another thread "just in case it is needed" to minimize the time the user will have to wait on it later. If there is time for it to complete, the user will not have to wait, but if it has not completed then waiting would be necessary.
Something like, opening a database in viewDidLoad: that will be needed when and if the user pushes a button on the screen. If I wait to open the database until the user actually pushes the button there is a lag. So I want to open it early. Since I don't know how long it will take to open and I don't know how long until the user hits the button, I need a way of saying, if that other task has not completed yet then wait, otherwise just go ahead.
For example:
#implementation aViewController
- (void) viewDidLoad {
[self.dbManager openOrCreateDbWithCompletionHandler: ^(NSError *err) {
if( err ) NSLog( #"There was a problem opening the database" );
}];
}
- (IBAction) goButtonTouched: (id) sender {
// Wait here until the database is open and ready to use.
if( ???DatabaseNotAvailableYet??? ) {
[self putSpinnerOnScreen];
???BlockProgressHereUntilDatabaseAvailable???
[self takeSpinnerOffScreen];
}
// Use the database...
NSManagedObjectContext *context = [self theDatabaseContext];
// Build the search request for the attribute desired
NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName: NSStringFromClass([Destinations class])];
request.predicate = [NSPredicate predicateWithFormat: #"dId == %#", sender.tag];
request.sortDescriptors = nil;
// Perform the search
NSError *error = nil;
NSArray *matches = [context executeFetchRequest: request error: &error];
// Use the search results
if( !matches || matches.count < 1 ) {
NSLog( #"Uh oh, got a nil back from my Destination fetch request!" );
UIAlertView *alert = [[UIAlertView alloc] initWithTitle: #"No Info"
message: #"The database did not have information for this selection"
delegate: nil
cancelButtonTitle: #"OK"
otherButtonTitles: nil];
[alert show];
} else {
MyOtherViewController *movc = [[MyOtherViewContoller alloc] init];
movc.destDetails = [matches lastObject];
[self.navigationController pushViewController: movc animated: YES];
}
}
#end
My hope is that there is never a spinner on the screen and never any delay for the user but, since I don't know how long it will take for the database connection to be established, I have to be prepared for it not being ready when the user pushes the button.
I can't use the call back for when openOrCreateDbWithCompletionHandler: completes since I don't want to do anything then, only when the user pushes the button.
I thought about using a semaphore but it seems like I would only signal it once (in the completion handler of the openOrCreateDbWithCompletionHandler: call) but would wait on it every time a button was pushed. That seems like it would only work for the first button push.
I thought about using dispatch_group_async() for openOrCreateDbWithCompletionHandler: then dispatch_group_wait() in goButtonTouched: but since openOrCreateDbWithCompletionHandler: does its work on another thread and returns immediately, I don't think the wait state would be set.
I can simply set a my own flag, something like before the openOrCreateDbWithCompletionHandler:, self.notOpenYet = YES;, then in its completion handler do self.notOpenYet = NO;, then in goButtonTouched: replace ???DatabaseNotAvailableYet??? with self.notOpenYet, but then how do I block progress on its state? Putting in loops and timers seems kludgy since I don't know if the wait will be nanoseconds or seconds.
This seems like a common enough situation, I am sure that you have all done this sort of thing commonly and it is poor education on my side, but I have searched stackOverflow and the web and have not found a satisfying answer.
I think, blocking execution is a bad habit unless you are building your own event loop, which is rarely necessary. You also don't need to do any GCD stuff in your case. Just get a feeling for async.
The following should work:
#implementation aViewController
- (void) viewDidLoad {
self.waitingForDB = NO;
self.databaseReady = NO;
[self.dbManager openOrCreateDbWithCompletionHandler: ^(NSError *err) {
if( err ){
NSLog( #"There was a problem opening the database" )
}else{
[self performSelectorOnMainThread:#selector(handleDatabaseReady) withObject:nil waitUntilDone:NO];
};
}];
}
- (void)handleDatabaseReady{
self.databaseReady = YES;
if(self.waitingForDB){
[self takeSpinnerOffScreen];
[self go];
}
}
- (IBAction) goButtonTouched: (id) sender {
// Wait here until the database is open and ready to use.
if( !self.databaseReady ) {
self.waitingForDB = YES;
[self putSpinnerOnScreen];
else{
[self go];
}
}
-(void)go{
// Use the database...
NSManagedObjectContext *context = [self theDatabaseContext];
// Build the search request for the attribute desired
NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName: NSStringFromClass([Destinations class])];
request.predicate = [NSPredicate predicateWithFormat: #"dId == %#", sender.tag];
request.sortDescriptors = nil;
// Perform the search
NSError *error = nil;
NSArray *matches = [context executeFetchRequest: request error: &error];
// Use the search results
if( !matches || matches.count < 1 ) {
NSLog( #"Uh oh, got a nil back from my Destination fetch request!" );
UIAlertView *alert = [[UIAlertView alloc] initWithTitle: #"No Info"
message: #"The database did not have information for this selection"
delegate: nil
cancelButtonTitle: #"OK"
otherButtonTitles: nil];
[alert show];
} else {
MyOtherViewController *movc = [[MyOtherViewContoller alloc] init];
movc.destDetails = [matches lastObject];
[self.navigationController pushViewController: movc animated: YES];
}
}
#end
Performing the call to handleDatabaseReady on the main thread guarantees that no race conditions in setting/reading your new properties will appear.
I'd go with the flag. You don't want to block the UI, just show the spinner and return from the goButtonTouched. However, you do need to cancel the spinner, if it is active, in openOrCreateDbWithCompletionHandler:.
This is rather a simple scenario. You make a method that does the stuff. Lets call it doStuff. From main thread, you call performSelectorInBackgroundThread:#selector(doStuff). Do not enable the button by default. Enable it at the end of doStuff so that user won't tap on it until you are ready. To make it more appealing, you can place a spinner in the place of the button and then replace it with the button when doStuff completes.
There are a number of classes and APIs you can use to achieve this kind of thing. You can use NSThread with synchronization primitives like semaphores and events to wait for it to finish when the user actually presses the button. You can use an NSOperation subclass (with an NSOperationQueue), and you can use GCD queues.
I would suggest you take a look at some the information in the Concurrency Programming Guide from Apple.
In your case you would probably be best served adding the operation to a GCD background queue using dispatch_async in combination with a semaphore which you can wait on when the user taps the button. You can check out the question "How do I wait for an asynchronously dispatched block to finish?" for an example.
Got a problem with the new Twitter.framework that I haven't been able to find a solution for yet.
Here is my code:
if ([TWTweetComposeViewController canSendTweet]){
TWTweetComposeViewController *twitter = [[TWTweetComposeViewController alloc] init];
[twitter addImage:tweetImage];
[twitter setInitialText:initalString];
[twitter addURL:url];
twitter.completionHandler = ^(TWTweetComposeViewControllerResult result) {
if (result == TWTweetComposeViewControllerResultDone) {
dispatch_async(dispatch_get_main_queue(), ^{
UIAlertView* alertView = [[UIAlertView alloc] initWithTitle:#"Tweeted"
message:#"You successfully tweeted"
delegate:self cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alertView show];
[alertView release];
});
} else if (result == TWTweetComposeViewControllerResultCancelled) {
dispatch_async(dispatch_get_main_queue(), ^{
UIAlertView* alertView = [[UIAlertView alloc] initWithTitle:#"Twitter"
message:#"Tweet has been canceled"
delegate:self
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alertView show];
[alertView release];
});
}
dispatch_async(dispatch_get_main_queue(), ^{
[self dismissModalViewControllerAnimated:YES];
});
};
[self presentViewController:twitter animated:YES completion:nil];
[twitter release];
}
Seems to be the standard way of implementing this although I made the addition of queuing the UI stuff on the main thread. The addImage, setInitialText and addURL parameters are all good. In, fact this works most of the time. The problem I am having is that occasionally when the TWTweetComposeViewController is alloc'd init the app freezes and I can see "twitterd session interrupted, restarting... " in the console. The app will hang sometimes for only a few seconds but more often it will hang for unreasonable amount of time (20 - 30 secs or more), I will get numerous of these messages and then the twitter controller will finally slide up. Occasionally, as well, it will just hang and never come back.
Was wondering it anybody has see this problem before or has any ideas on a solution to this problem?
Thanks in advance.
I never add these problems with the twitter view controller. I used my code pasted in this post: https://stackoverflow.com/questions/9314308/can-twtweetcomposeviewcontroller-tweet-sheet-rotate-to-landscape
You can try it, just change it to "self" when you dismiss or present in modal view, as I'm using a different view controller.