Search Results

Search found 10298 results on 412 pages for 'self teaching'.

Page 113/412 | < Previous Page | 109 110 111 112 113 114 115 116 117 118 119 120  | Next Page >

  • Rails routing problem

    - by Steve
    I am new to Rails routing and I currently have a problem and hope someone can explain it to me. I am using Rails 2.3.5 Firstly, let me describe my working-fine code: I have a text example, which has a controller (cars_controller) with an update action (along with some other actions). The update action needs the :id parameter. The edit.html.erb has a form: <% form_for :car, :url = {:controller = 'cars', :action = 'update' } % ... # rest of the form content. In the configuration/routes.rb, I have a self-defined routing rule for update: map.connect 'car/update/:id', :controller = 'cars', :action = 'update' This works fine. Secondly, I change the code. All I change is the self-defined routing rule to map.connect 'car/:action/:id, :controller = 'cars' To me, this rule covers the self-written routing rule. Of course, this rule is also used by other actions such as edit. But the edit.html.erb doesn't work. It complains that update action misses the :id parameter. I have to change the form_for helper to: <% form_for :car, :url = {:controller = 'cars', :action = 'update', :id = @car }% ... # @car is the instance passed to edit view. I know that if missing the :id parameter, update action will complain. What I don't understand is why my first code works (with my self-defined routing rule) but my second code fails. It seems to me that I didn't provide :id parameter in my self-defined routing rule. Anyone has an idea?

    Read the article

  • Second call to AVAudioPlayer -> EXC_BAD_ACCESS (code posted, what did I miss?)

    - by Jordan
    I'm using this code to play a different mp3 files with every call. The first time through works great. The second time crash, as indicated below. .h AVAudioPlayer *player; @property (nonatomic, retain) AVAudioPlayer *player; .m -(void)load:(NSURL *)aFileURL { if (aFileURL) { AVAudioPlayer *newPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL: aFileURL error: nil]; [aFileURL release]; self.player = newPlayer; // CRASHES HERE EXC_BAD_ACCESS with second MP3a [newPlayer release]; [self.player prepareToPlay]; [self.player setDelegate:self]; } } I know I must have missed something, any ideas?

    Read the article

  • python-iptables: Cryptic error when allowing incoming TCP traffic on port 1234

    - by Lucas Kauffman
    I wanted to write an iptables script in Python. Rather than calling iptables itself I wanted to use the python-iptables package. However I'm having a hard time getting some basic rules setup. I wanted to use the filter chain to accept incoming TCP traffic on port 1234. So I wrote this: import iptc chain = iptc.Chain(iptc.TABLE_FILTER,"INPUT") rule = iptc.Rule() target = iptc.Target(rule,"ACCEPT") match = iptc.Match(rule,'tcp') match.dport='1234' rule.add_match(match) rule.target = target chain.insert_rule(rule) However when I run this I get this thrown back at me: Traceback (most recent call last): File "testing.py", line 9, in <module> chain.insert_rule(rule) File "/usr/local/lib/python2.6/dist-packages/iptc/__init__.py", line 1133, in insert_rule self.table.insert_entry(self.name, rbuf, position) File "/usr/local/lib/python2.6/dist-packages/iptc/__init__.py", line 1166, in new obj.refresh() File "/usr/local/lib/python2.6/dist-packages/iptc/__init__.py", line 1230, in refresh self._free() File "/usr/local/lib/python2.6/dist-packages/iptc/__init__.py", line 1224, in _free self.commit() File "/usr/local/lib/python2.6/dist-packages/iptc/__init__.py", line 1219, in commit raise IPTCError("can't commit: %s" % (self.strerror())) iptc.IPTCError: can't commit: Invalid argument Exception AttributeError: "'NoneType' object has no attribute 'get_errno'" in <bound method Table.__del__ of <iptc.Table object at 0x7fcad56cc550>> ignored Does anyone have experience with python-iptables that could enlighten on what I did wrong?

    Read the article

  • Root view controllers and modal dialogs

    - by Tony
    In a custom UIViewController, if I have a member UINavigationController that I initialize with self as the root view, like this: navController = [[UINavigationController alloc] initWithRootViewController:self]; then presenting a modal dialog does not hide the tab bar at the bottom of the screen. The result is that if the user switches to a different tab while a modal dialog is displayed, when they pop back to the tab that was displaying a modal dialog then subsequent calls to presentModalViewController do not display a modal dialog at all, even if I call dismissModalViewControllerAnimated as a result of the tab switch. If I initialize the UINavigationController with out setting self as the root controller, navigationController = [[UINavigationController alloc] init]; then the tab bar is hidden as expected. I've changed things in my program so that this isn't really an issue for me anymore, but I'm not sure that I understand why this is happening. Is it considered bad practice to have a navigation controller with self as the root, if the nav controller is going to be displaying modal dialogs?

    Read the article

  • Reloading the model of a TTTableViewController

    - by user341338
    My problem is that I have a Register Controller and a Login Controller. The Login Screen displays a Login Screen or a Logout Screen depending if a user is logged in. Now when a user registers, does not close the app, and then goes to the Login Screen it will still display a Login Screen, although there is a logged in user already. This is because the Screen is created when the application loads and does not change afterwards. I tried doing this: - (id)init { if (self = [super init]) { [self invalidateModel]; [self reload]; but that did not work, since it is only called on the first init. then i tried: - (void)viewDidLoad { [self invalidateModel]; [self reload]; } But that method had the same problem. Then I found this method: - (TTNavigationMode)navigationModeForURL:(NSString*)URL; with the following options: typedef enum { TTNavigationModeNone, TTNavigationModeCreate, // a new view controller is created each time TTNavigationModeShare, // a new view controller is created, cached and re-used TTNavigationModeModal, // a new view controller is created and presented modally TTNavigationModeExternal, // an external app will be opened } TTNavigationMode; It seems like TTNavigationModeCreate would be the right thing to use, but I have no clue how to use it. Any help? Thnx.

    Read the article

  • Multiprogramming in Django, writing to the Database

    - by Marcus Whybrow
    Introduction I have the following code which checks to see if a similar model exists in the database, and if it does not it creates the new model: class BookProfile(): # ... def save(self, *args, **kwargs): uniqueConstraint = {'book_instance': self.book_instance, 'collection': self.collection} # Test for other objects with identical values profiles = BookProfile.objects.filter(Q(**uniqueConstraint) & ~Q(pk=self.pk)) # If none are found create the object, else fail. if len(profiles) == 0: super(BookProfile, self).save(*args, **kwargs) else: raise ValidationError('A Book Profile for that book instance in that collection already exists') I first build my constraints, then search for a model with those values which I am enforcing must be unique Q(**uniqueConstraint). In addition I ensure that if the save method is updating and not inserting, that we do not find this object when looking for other similar objects ~Q(pk=self.pk). I should mention that I ham implementing soft delete (with a modified objects manager which only shows non-deleted objects) which is why I must check for myself rather then relying on unique_together errors. Problem Right thats the introduction out of the way. My problem is that when multiple identical objects are saved in quick (or as near as simultaneous) succession, sometimes both get added even though the first being added should prevent the second. I have tested the code in the shell and it succeeds every time I run it. Thus my assumption is if say we have two objects being added Object A and Object B. Object A runs its check upon save() being called. Then the process saving Object B gets some time on the processor. Object B runs that same test, but Object A has not yet been added so Object B is added to the database. Then Object A regains control of the processor, and has allready run its test, even though identical Object B is in the database, it adds it regardless. My Thoughts The reason I fear multiprogramming could be involved is that each Object A and Object is being added through an API save view, so a request to the view is made for each save, thus not a single request with multiple sequential saves on objects. It might be the case that Apache is creating a process for each request, and thus causing the problems I think I am seeing. As you would expect, the problem only occurs sometimes, which is characteristic of multiprogramming or multiprocessing errors. If this is the case, is there a way to make the test and set parts of the save() method a critical section, so that a process switch cannot happen between the test and the set?

    Read the article

  • How do I get save (no exclamation point) semantics in an ActiveRecord transaction?

    - by James A. Rosen
    I have two models: Person and Address which I'd like to create in a transaction. That is, I want to try to create the Person and, if that succeeds, create the related Address. I would like to use save semantics (return true or false) rather than save! semantics (raise an ActiveRecord::StatementInvalid or not). This doesn't work because the user.save doesn't trigger a rollback on the transaction: class Person def save_with_address(address_options = {}) transaction do self.save address = Address.build(address_options) address.person = self address.save end end end (Changing the self.save call to an if self.save block around the rest doesn't help, because the Person save still succeeds even when the Address one fails.) And this doesn't work because it raises the ActiveRecord::StatementInvalid exception out of the transaction block without triggering an ActiveRecord::Rollback: class Person def save_with_address(address_options = {}) transaction do save! address = Address.build(address_options) address.person = self address.save! end end end The Rails documentation specifically warns against catching the ActiveRecord::StatementInvalid inside the transaction block. I guess my first question is: why isn't this transaction block... transacting on both saves?

    Read the article

  • trouble to connect with AppStore in my InAppPurchase application(iPhone)

    - by riteshkumar1905
    There is problem to connect AppStore in my application. All things run fine in Simulator.But When i go with iPhone then AppStore is not connected.. I am also enclose the code which i call on button....... import "BuyController.h" import "InAppPurchaseManager.h" import "SKProducts.h" define kInAppPurchaseProUpgradeProductId @"com.vigyaapan.iWorkOut1" @implementation BuyController (IBAction)buy:(id)sender { /* get the product description (defined in early sections)*/ //[self requestProUpgradeProductData]; { if ([SKPaymentQueue canMakePayments]) { InAppPurchaseManager *Observer = [[InAppPurchaseManager alloc] init]; [[SKPaymentQueue defaultQueue] addTransactionObserver:Observer]; //NSURL *sandboxStoreURL = [[NSURL alloc]initWithString:@"http://sandbox.itunes.apple.com/verifyReceipt"]; //[[UIApplication sharedApplication]openURL:[NSURL URLWithString:@"http://sandbox.itunes.apple.com"]]; [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"http://phobos.apple.com/WebObjects/ com.vigyaapan.iWorkOut1?id=9820091347&;amp;amp;amp;amp;mt=8"]]; //[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"http://phobos.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=301349397&;amp;amp;amp;amp;mt=8"]]; SKPayment *payment = [SKPayment paymentWithProductIdentifier:@"com.vigyaapan.iWorkOut1"]; [[SKPaymentQueue defaultQueue] addPayment:payment]; } else { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"MyApp" message:@"You are not authorized to purchase from AppStore" delegate:self cancelButtonTitle:@"OK" otherButtonTitles: nil]; [alert show]; [alert release]; } //return [SKPaymentQueue canMakePayments]; } SKPayment *payment = [SKPayment paymentWithProductIdentifier:kInAppPurchaseProUpgradeProductId]; [[SKPaymentQueue defaultQueue] addPayment:payment]; //[self requestProUpgradeProductData]; /* get the product description (defined in early sections)*/ } /* // The designated initializer. Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad. - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle )nibBundleOrNil { if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) { // Custom initialization } return self; }/ // Implement viewDidLoad to do additional setup after loading the view, typically from a nib. - (void)viewDidLoad { [super viewDidLoad]; } // Override to allow orientations other than the default portrait orientation. - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { // Return YES for supported orientations return (interfaceOrientation == UIInterfaceOrientationPortrait); } (void)didReceiveMemoryWarning { // Releases the view if it doesn't have a superview. [super didReceiveMemoryWarning]; // Release any cached data, images, etc that aren't in use. } (void)viewDidUnload { // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; } (void)dealloc { [super dealloc]; } @end

    Read the article

  • Need help with a possible memory management problem(leak) regarding NSMutableArray

    - by user309030
    Hi, I'm a beginner level programmer trying to make a game app for the iphone and I've encountered a possible issue with the memory management (exc_bad_access) of my program so far. I've searched and read dozens of articles regarding memory management (including apple's docs) but I still can't figure out what exactly is wrong with my codes. So I would really appreciate it if someone can help clear up the mess I made for myself. - (void)viewDidLoad { [super viewDidLoad]; self.gameState = gameStatePaused; fencePoleArray = [[NSMutableArray alloc] init]; fencePoleImageArray = [[NSMutableArray alloc] init]; fenceImageArray = [[NSMutableArray alloc] init]; mainField = CGRectMake(10, 35, 310, 340); .......... [NSTimer scheduledTimerWithTimeInterval:0.05 target:self selector:@selector(gameLoop) userInfo:nil repeats:YES]; } So basically, the player touches the screen to set up the fences/poles -(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { if(.......) { ....... } else { UITouch *touch = [[event allTouches] anyObject]; currentTapLoc = [touch locationInView:touch.view]; NSLog(@"%i, %i", (int)currentTapLoc.x, (int)currentTapLoc.y); if(CGRectContainsPoint(mainField, currentTapLoc)) { if([self checkFence]) { onFencePole++; //this 3 set functions adds their respective objects into the 3 NSMutableArrays using addObject: [self setFencePole]; [self setFenceImage]; [self setFencePoleImage]; ....... } } else { ....... } } } } The setFence function (setFenceImage and setFencePoleImage is similar to this) -(void)setFencePole { Fence *fencePole; if (!elecFence) { fencePole = [[Fence alloc] initFence:onFencePole fenceType:1 fencePos:currentTapLoc]; } else { fencePole = [[Fence alloc] initFence:onFencePole fenceType:2 fencePos:currentTapLoc]; } [fencePoleArray addObject:fencePole]; [fencePole release]; and whenever I press a button in the game, endOpenState is called to clear away all the extra images(fence/poles) on the screen and also to remove all existing objects in the 3 NSMutableArray -(void)endOpenState { ........ int xMax = [fencePoleArray count]; int yMax = [fenceImageArray count]; for (int x = 0; x < xMax; x++) { [[fencePoleImageArray objectAtIndex:x] removeFromSuperview]; } for (int y = 0; y < yMax; y++) { [[fenceImageArray objectAtIndex:y] removeFromSuperview]; } [fencePoleArray removeAllObjects]; [fencePoleImageArray removeAllObjects]; [fenceImageArray removeAllObjects]; ........ } The crash happens here at the checkFence function. -(BOOL)checkFence { if (onFencePole == 0) { return YES; } else if (onFencePole >= 1 && onFencePole < currentMaxFencePole - 1) { CGPoint tempPoint1 = currentTapLoc; CGPoint tempPoint2 = [[fencePoleArray objectAtIndex:onFencePole-1] returnPos]; // the crash happens at this line if ([self checkDistance:tempPoint1 point2:tempPoint2]) { return YES; } else { return NO; } } else if (onFencePole == currentMaxFencePole - 1) { ...... } else { return NO; } } What I'm thinking of is that fencePoleArray got messed up when I used [fencePoleArray removeAllObjects] because it doesn't crash when I comment it out. It would really be great if someone can explain to me what went wrong. And thanks in advance.

    Read the article

  • Update a tableView with a plist took from another table

    - by Pheel
    Background: I have a tab bar application, which has a tableView as the "heart" of the app. It loads data from a plist and, through a button that checks if there are any updates on the remote plist file, updates the local plist with the remote contents. Then, i have another tableView, that should display only those plist items that have a bool value set to YES. Now i want to add a button to the second table that reloads the plist took from the first table. Expected: When i update the local plist from the first table and when i press the button on the second table, the 2nd table is supposed to update and show the cells with that bool value set to YES. (Note: I set YES as default to some items on plist). What happens: The first table updates its content from remote. The second table shows the old items with the value set to YES. When i press the button to refresh data, it reads the plist fine (by logging it, it has the same contents of the first table -only those set to YES-),but it doesn't update data even if i have [self.tableView reloadData];. When i close the app and open it again, the second table is filled with the right items. :\ Code i'm using: //Reading Plist { NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES); NSString *plistPath = [[documentPaths lastObject] stringByAppendingPathComponent:@"myPlist.plist"]; NSFileManager *fMgr = [NSFileManager defaultManager]; if (![fMgr fileExistsAtPath:plistPath]) { plistPath = [[NSBundle mainBundle] pathForResource:@"myPlist" ofType:@"plist"]; } NSMutableArray *returnArr = [NSMutableArray arrayWithContentsOfFile:plistPath]; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"isFav == YES"]; for (NSDictionary *sect in returnArr) { NSArray *arr = [sect objectForKey:@"Rows"]; [sect setValue:[arr filteredArrayUsingPredicate:predicate] forKey:@"Rows"]; } [self.tableView reloadData]; } //Refresh data button - (void) refreshTable:(id)sender { NSLog(@"plist read"); [self readPlist]; NSLog(@"refreshed plist:%@",[self readPlist]); [self.tableView reloadData]; } Does anyone know why the table is not updating?

    Read the article

  • Popping multiple levels in UITableViewController

    - by LavaSlider
    I would like to be able to pop multiple views from a UITableViewController stack. For example in the Apple DrillDownSave example, when viewing Level 3 to go back to Level 1 or when viewing an Item to go back to Level 2 when a button is pushed. I tried: [self.navigationController.parentViewController.navigationController popViewControllerAnimated: NO]; [self.navigationController popViewControllerAnimated: NO]; and [self.navigationController popViewControllerAnimated: NO]; [self.navigationController.parentViewController.navigationController popViewControllerAnimated: NO]; but these leave me the same place as just a single popViewControllerAnimated:. Is there an easy way to do this?

    Read the article

  • Crashing when masking an image

    - by shameer
    I am trying to mask an image with a 'mask image". its work fine at first time. but when i try one more time with in the application with same mask image . Application crashed. but when trying with another mask image it works fine. Why this happens? pls help? Console shows ": CGImageMaskCreate: invalid mask bits/component: 4294967295." (UIImage*) maskImage:(UIImage *)image withMask:(UIImage *)maskImage { CGImageRef maskRef = maskImage.CGImage; CGImageRef mask = CGImageMaskCreate(CGImageGetWidth(maskRef), CGImageGetHeight(maskRef), CGImageGetBitsPerComponent(maskRef), CGImageGetBitsPerPixel(maskRef), CGImageGetBytesPerRow(maskRef), CGImageGetDataProvider(maskRef), NULL, false); CGImageRef masked = CGImageCreateWithMask([image CGImage], mask); UIImage *img2=[UIImage imageWithCGImage:masked]; CGImageRelease(maskRef); CGImageRelease(mask); CGImageRelease(masked); return img2; } fun1() { view.image=[self maskImage:image1 withMask:[UIImage imageNamed:@"image2.png"]]; } fun2() { view.image=[self maskImage:image1 withMask:[UIImage imageNamed:@"image2.png"]]; view.image=[self maskImage:image1 withMask:[UIImage imageNamed:@"image3.png"]]; } fun3() { view.image=[self maskImage:image1 withMask:[UIImage imageNamed:@"image2.png"]]; view.image=[self maskImage:image1 withMask:[UIImage imageNamed:@"image2.png"]]; } When calling fun1 and fun2 apllication works fine. Application crashing when calling fun3.

    Read the article

  • How can I modify a scalar reference passed to a subroutine reference

    - by Mark
    I have a function to convert documents into different formats, which then calls another function based on the type document. It's pretty straight forward for everything aside from HTML documents which require a bit of cleaning up, and that cleaning up is different based on where it's come from. So I had the idea that I could pass a reference to a subroutine to the convert function so the caller has the opportunity to modify the HTML, kinda like so (I'm not at work so this isn't copy-and-pasted): package Converter; ... sub convert { my ($self, $filename, $coderef) = @_; if ($filename =~ /html?$/i) { $self->_convert_html($filename, $coderef); } } sub _convert_html { my ($self, $filename, $coderef) = @_; my $html = $self->slurp($filename); $coderef->(\$html); #this modifies the html $self->save_to_file($filename, $html); } which is then called by: Converter->new->convert("./whatever.html", sub { s/<html>/<xml>/i }); I've tried a couple of different things along these lines but I keep on getting 'Use of uninitialized value in substitution (s///)'. Is there any way of doing what I'm trying to do? Thanks

    Read the article

  • viewDidLoad never called in Sub-classed UIViewController

    - by Steve
    I've run into some trouble with loading a sub-classed UIViewController from a nib. My viewDidLoad function is never called. The super-class has no nib, but the sub-classes each have their own. i.e. @interface SuperClass : UIViewController { } @end @interface SubClass : SuperClass{ } @end @implementation SubClass - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; if (self) { } return self; } - (void)viewDidLoad{ // Never called } The view is loaded from a nib as follows: SubClass *scvc = [[SubClass alloc] initWithNibName:@"SubClass" bundle:nil]; [self.navigationController pushViewController:scvc animated:YES]; [scvc release]; There is a nib file with this name and it has it's file owner's class set properly. viewDidLoad is not called in the child or super. Any ideas?

    Read the article

  • Getting Unit Tests to work with Komodo IDE for Python

    - by devoured elysium
    I've tried to run the following code on Komodo IDE (for python): import unittest class MathLibraryTests(unittest.TestCase): def test1Plus1Equals2(self): self.assertEqual(1+1, 2) Then, I created a new test plan, pointing to this project(file) directory and tried to run it the test plan. It seems to run but it doesn't seem to find any tests. If I try to run the following code with the "regular" run command (F7) class MathLibraryTests(unittest.TestCase): def testPlus1Equals2(self): self.assertEqual(1+1, 2) if __name__ == "__main__": unittest.main() it works. I get the following output: ---------------------------------------------------------------------- Ran 1 test in 0.000s OK What might I be doing wrong?

    Read the article

  • Cast an instance of a class to a @protocol in Objective-C

    - by Ford
    I have an object (a UIViewController) which may or may not conform to a protocol I've defined. I know I can determine if the object conforms to the protocol, then safely call the method: if([self.myViewController conformsToProtocol:@protocol(MyProtocol)]) { [self.myViewController protocolMethod]; // <-- warning here } However, XCode shows a warning: warning 'UIViewController' may not respond to '-protocolMethod' What's the right way to prevent this warning? I can't seem to cast self.myViewController as a MyProtocol class. Update Andy's answer below is close, but includes an unneccesary '*'. The following works: [(id<MyProtocol>)self.myViewController protocolMethod];

    Read the article

  • iPad: CoreData FetchedRequest Ignores Changes in Predicate

    - by Michael
    Hi there, While programming an iPad-app, I'm just running into trouble using a fetchedResultsController with a "dynamic" predicate. it seems the changes to the predicate get ignored. No matter how the predicate changes, I always get the result of the first fetch ... same code runs without no problems on iphone-env (3.1.x) !! sample : - (void)performSearch:(NSString *)searchText { self.displaySearchResults = TRUE; NSPredicate *predicate = [NSPredicate predicateWithFormat:@"searchWords contains[cd] %@", searchText]; [self.fetchedSearchResultsController.fetchRequest setPredicate:predicate]; NSError *error = nil; if (![self.fetchedSearchResultsController performFetch:&error]) { NSLog(@"Unresolved error %@, %@", error, [error userInfo]); abort(); } if(deviceIsIPad) { [self showSearchResults]; } else { [cookBookOverview reloadData]; } } can anyone help plz ? btw.: excuse my painful english ;-)

    Read the article

  • Python PyQT4 - Adding an unknown number of QComboBox widgets to QGridLayout

    - by ZZ
    Hi all, I want to retrieve a list of people's names from a queue and, for each person, place a checkbox with their name to a QGridLayout using the addWidget() function. I can successfully place the items in a QListView, but they just write over the top of each other rather than creating a new row. Does anyone have any thoughts on how I could fix this? self.chk_People = QtGui.QListView() items = self.jobQueue.getPeopleOffQueue() for item in items: QtGui.QCheckBox('%s' % item, self.chk_People) self.jobQueue.getPeopleOffQueue() would return something like ['Bob', 'Sally', 'Jimmy'] if that helps.

    Read the article

  • iPhone: Problems releasing UIViewController in a multithreaded environment

    - by bart-simpson
    Hi! I have a UIViewController and in that controller, i am fetching an image from a URL source. The image is fetched in a separate thread after which the user-interface is updated on the main thread. This controller is displayed as a page in a UIScrollView parent which is implemented to release controllers that are not in view anymore. When the thread finishes fetching content before the UIViewController is released, everything works fine - but when the user scrolls to another page before the thread finishes, the controller is released and the only handle to the controller is owned by the thread making releaseCount of the controller equals to 1. Now, as soon as the thread drains NSAutoreleasePool, the controller gets releases because the releaseCount becomes 0. At this point, my application crashes and i get the following error message: bool _WebTryThreadLock(bool), 0x4d99c60: Tried to obtain the web lock from a thread other than the main thread or the web thread. This may be a result of calling to UIKit from a secondary thread. Crashing now... The backtrace reveals that the application crashed on the call to [super dealloc] and it makes total sense because the dealloc function must have been triggered by the thread when the pool was drained. My question is, how i can overcome this error and release the controller without leaking memory? One solution that i tried was to call [self retain] before the pool is drained so that retainCount doesn't fall to zero and then using the following code to release controller in the main thread: [self performSelectorOnMainThread:@selector(autorelease) withObject:nil waitUntilDone:NO]; Unfortunately, this did not work out. Below is the function that is executed on a thread: - (void)thread_fetchContent { NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; NSURL *imgURL = [NSURL URLWithString:@"http://www.domain.com/image.png"]; // UIImage *imgHotspot is declared as private - The image is retained // here and released as soon as it is assigned to UIImageView imgHotspot = [[[UIImage alloc] initWithData: [NSData dataWithContentsOfURL: imgURL]] retain]; if ([self retainCount] == 1) { [self retain]; // increment retain count ~ workaround [pool drain]; // drain pool // this doesn't work - i get the same error [self performSelectorOnMainThread:@selector(autorelease) withObject:nil waitUntilDone:NO]; } else { // show fetched image on the main thread - this works fine! [self performSelectorOnMainThread:@selector(showImage) withObject:nil waitUntilDone:NO]; [pool drain]; } } Please help! Thank you in advance.

    Read the article

  • conceptual question : what do performSelectorOnMainThread do?

    - by hib
    Hello all, I just come across this strange situation . I was using the technique of lazy image loading from apple examples . when I was used the class in my application it gave me topic to learn but don't what was actually happening there . So here goes the scenario : I think everybody has seen the apple lazytableimagesloading . I was reloading my table on finishing the parsing of data : - (void)didFinishParsing:(NSMutableArray *)appList { self.upcomingArray = [NSMutableArray arrayWithArray:loadedApps]; // we are finished with the queue and our ParseOperation [self.upcomingTableView reloadData]; self.queue = nil; // we are finished with the queue and our ParseOperation } but as a result the the connection was not starting and images were not loading . when I completely copy the lazyimageloading and I replaced the above code with the following code it works fine - (void)didFinishParsing:(NSMutableArray *)appList { [self performSelectorOnMainThread:@selector(handleLoadedApps:) withObject:appList waitUntilDone:NO]; self.queue = nil; // we are finished with the queue and our ParseOperation } So I want to know what is the concept behind this . Please let me know if you can not understand the question or details are not enough because I desperately want to know why it is like this ?

    Read the article

  • how to format date when i load data from google-app-engine..

    - by zjm1126
    i use remote_api to load data from google-app-engine. appcfg.py download_data --config_file=helloworld/GreetingLoad.py --filename=a.csv --kind=Greeting helloworld the setting is: class AlbumExporter(bulkloader.Exporter): def __init__(self): bulkloader.Exporter.__init__(self, 'Greeting', [('author', str, None), ('content', str, None), ('date', str, None), ]) exporters = [AlbumExporter] and i download a.csv is : the date is not readable , and the date in appspot.com admin is : so how to get the full date ?? thanks i change this : class AlbumExporter(bulkloader.Exporter): def __init__(self): bulkloader.Exporter.__init__(self, 'Greeting', [('author', str, None), ('content', str, None), ('date', lambda x: datetime.datetime.strptime(x, '%m/%d/%Y').date(), None), ]) exporters = [AlbumExporter] but the error is :

    Read the article

  • Understanding Ruby class vs instance methods

    - by randombits
    I have the following code: #!/usr/bin/ruby class Person def self.speak p = self.new puts "Hello" p.chatter end private def chatter puts "Chattering" end end p = Person.new Person.speak I'd like to make chatter private, accessible only within p.. but I want p to be able to access it within the class method. Is there a better way to design this so chatter isn't available to the public, but a "factory" method like self.speak can call chatter?

    Read the article

  • Please explain this Rails method to me like I'm a little kid.

    - by Senthil
    I found this in Ryan Bates' railscast site, but not sure how it works. #models/comment.rb def req=(request) self.user_ip = request.remote_ip self.user_agent = request.env['HTTP_USER_AGENT'] self.referrer = request.env['HTTP_REFERER'] end #blogs_controller.rb def create @blog = Blog.new(params[:blog]) @blog.req = request if @blog.save ... I see he is saving the user ip, user agent and referrer, but am confused with the req=(request) line. Any help is appreciated. Thanks

    Read the article

  • iphone quartz drawing 2 lines on top of each other causes worm effect

    - by Leonard
    I'm using Quartz-2D for iPhone to display a route on a map. The route is colored according to temperature. Because some streets are colored yellow, I am using a slightly thicker black line under the route line to create a border effect, so that yellow parts of the route are spottable on yellow streets. But, even if the black line is as thick as the route line, the whole route looks like a worm (very ugly). I tought this was because I was drawing lines from waypoint to waypoint, instead using the last waypoint as the next starting waypoint. That way if there is a couple of waypoints missing, the route will still have no cuts. What do I need to do to display both lines without a worm effect? -(void) drawRect:(CGRect) rect { CSRouteAnnotation* routeAnnotation = (CSRouteAnnotation*)self.routeView.annotation; // only draw our lines if we're not int he moddie of a transition and we // acutally have some points to draw. if(!self.hidden && nil != routeAnnotation.points && routeAnnotation.points.count > 0) { CGContextRef context = UIGraphicsGetCurrentContext(); Waypoint* fromWaypoint = [[Waypoint alloc] initWithDictionary:[routeAnnotation.points objectAtIndex:0]]; Waypoint* toWaypoint; for(int idx = 1; idx < routeAnnotation.points.count; idx++) { toWaypoint = [[Waypoint alloc] initWithDictionary:[routeAnnotation.points objectAtIndex:idx]]; CLLocation* fromLocation = [fromWaypoint getLocation]; CGPoint fromPoint = [self.routeView.mapView convertCoordinate:fromLocation.coordinate toPointToView:self]; CLLocation* toLocation = [toWaypoint getLocation]; CGPoint toPoint = [self.routeView.mapView convertCoordinate:toLocation.coordinate toPointToView:self]; routeAnnotation.lineColor = [fromWaypoint.weather getTemperatureColor]; CGContextBeginPath(context); CGContextSetLineWidth(context, 3.0); CGContextSetStrokeColorWithColor(context, [UIColor blackColor].CGColor); CGContextMoveToPoint(context, fromPoint.x, fromPoint.y); CGContextAddLineToPoint(context, toPoint.x, toPoint.y); CGContextStrokePath(context); CGContextClosePath(context); CGContextBeginPath(context); CGContextSetLineWidth(context, 3.0); CGContextSetStrokeColorWithColor(context, routeAnnotation.lineColor.CGColor); CGContextMoveToPoint(context, fromPoint.x, fromPoint.y); CGContextAddLineToPoint(context, toPoint.x, toPoint.y); CGContextStrokePath(context); CGContextClosePath(context); fromWaypoint = toWaypoint; } [fromWaypoint release]; [toWaypoint release]; } } Also, I get a <Error>: CGContextClosePath: no current point. error, which I think is bullshit. Please hint me! :)

    Read the article

  • How do I find the "concrete class" of a django model baseclass

    - by Mr Shark
    I'm trying to find the actual class of a django-model object, when using model-inheritance. Some code to describe the problem: class Base(models.model): def basemethod(self): ... class Child_1(Base): pass class Child_2(Base): pass If I create various objects of the two Child classes and the create a queryset containing them all: Child_1().save() Child_2().save() (o1, o2) = Base.objects.all() I want to determine if the object is of type Child_1 or Child_2 in basemethod, I can get to the child object via o1.child_1 and o2.child_2 but that reconquers knowledge about the childclasses in the baseclass. I have come up with the following code: def concrete_instance(self): instance = None for subclass in self._meta.get_all_related_objects(): acc_name = subclass.get_accessor_name() try: instance = self.__getattribute__(acc_name) return instance except Exception, e: pass But it feels brittle and I'm not sure of what happens when if I inherit in more levels.

    Read the article

< Previous Page | 109 110 111 112 113 114 115 116 117 118 119 120  | Next Page >