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  • iPhone Core Data does not refresh table

    - by Brian515
    Hi all, I'm trying to write an application with Core Data, and I have been able to successfully read and write to the core data database. However, if I write to the database in one view controller, my other view controllers will not see the change until the app is closed then reopened again. This is really frustrating. I'm not entirely sure how to get the refresh - (void)refreshObject:(NSManagedObject *)object mergeChanges:(BOOL)flag method to work. How do I get a reference to my managed object? Anyways, here's the code I'm using to read the data back. This is in the viewDidLoad method. NSFetchRequest *request = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Website" inManagedObjectContext:managedObjectContext]; [request setEntity:entity]; NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"siteName" ascending:NO]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil]; [request setSortDescriptors:sortDescriptors]; [sortDescriptor release]; [sortDescriptors release]; NSError *error = nil; NSMutableArray *mutableFetchResults = [[managedObjectContext executeFetchRequest:request error:&error] mutableCopy]; if(mutableFetchResults == nil) { //Handle the error } [self setNewsTitlesArray:mutableFetchResults]; [mutableFetchResults release]; [request release]; [newsSourcesTableView reloadData]; Thanks for help in advance!

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  • My 3D object (opengl es) is disappearing behind the iPhone camera view

    - by KLC
    I have an augmented reality iPhone app that I am converting from Core Animation to OpenGL ES 1.1. I have added code that has been modified from the Apple OpenGL template. My problem is that my 3D object , when translating along the negative Z-axis (away from the user), appears to disappear into the camera view, until its completely gone. I have experimented with several solutions, but to no avail. What I have determined: Using the 3D icosahedron from Jeff Lamarche's blog here, the object starts it at 0,0,0 and then translates with decreasing z coordinates. By the time the z value reaches -2.0f, the object is gone. It appears as if it is disappearing behind the camera view. This is how I set my frustrum & viewport (unchanged from Apple's code) glMatrixMode(GL_PROJECTION); size = zNear * tanf(DEGREES_TO_RADIANS(fieldOfView) / 2.0); //Grab the size of the screen CGRect rect = self.bounds; glFrustumf(-size, size, -size / (rect.size.width / rect.size.height), size / (rect.size.width / rect.size.height), zNear, zFar); glViewport(0, 0, rect.size.width, rect.size.height); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); What I have tried: The camera view is the main view and several other views are added to it as subviews, including the openGLView. I have commented those views out for test purposes. I have applied CATransforms to move the openGLView in the z direction -500 and +500, and done the same to the camera view. I have also changed the zFar in the above code to 1.0f, and it still disappears at z position of -2.0, which doesn't make sense (shouldn't it disappear at z=1.0?) My experimentation has got me more confused than when I started ( which usually means I am missing a key piece, but I can't figure out what). Thanks for your help.

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  • How do I reliably get the size of my iPhone view taking rotations into consideration?

    - by Sebastian Celis
    My application uses a UITabBarController, multiple UINavigationControllers, and supports autorotation. In order to properly layout the subviews within each UIViewController's main view, I really need to know the size available to the UIViewContoller. I need this size to take the UINavigationBar, the UITabBar, and the status bar all into account, and thus only return the size available to the content view. I thought for sure I could use the following from within the UIViewController's code: CGRect viewControllerBounds = [[self view] bounds]; However, there are a couple of issues with this approach: The first time the view is loaded, viewControllerBounds reports the view as being 320 pixels wide by 460 pixels tall. This is wrong. With a status bar and a navigation bar showing, the height should only be 416 pixels. However, if I rotate the simulator to landscape and then rotate back, the height of viewControllerBounds changes to 416. If I rotate the first view in the navigation controller to landscape mode and then push another view controller onto the stack, viewControllerBounds for the new view reports a width of 300 pixels and a height of 480 pixels. So the view's bounds didn't even take the rotation into account. Is there a better way to do this? I really don't want to have to start hardcoding the widths and heights of all the various UI elements the iPhone OS provides. I have tried setting the autoresizing mask of the UIViewController's view, but that doesn't seem to change anything. The views definitely seem to be displaying properly. When I set a background color that view looks like it takes up all of the space available to it. Any pointers would be greatly appreciated.

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  • iPhone and OpenCV

    - by gn-mithun
    Hello, I am writing an application to create a movie file from a bunch of images on an iPhone. I am using OpenCv. I downloaded openCv static libraries for arm(iPhones native instruction architecture) and the libraries were generated just fine. There were no problems linking to them libraries. As a first step, i was trying to create a .avi file using one image, to see if it works. But cvCreateVideoWriter always returns me a NULL value. I did some searchin and i believe its due to the codec not being present. I am trying this on the iPhone simulator. this is what i do... (void)viewDidLoad { [super viewDidLoad]; UIImage *anImage = [UIImage imageNamed:@"1.jpg"]; IplImage *img_color = [self CreateIplImageFromUIImage:anImage]; //The image gets created just fine CvVideoWriter *writer = cvCreateVideoWriter("out.avi",CV_FOURCC('P','I','M','1'), 25,cvSize(320,480),1); //writer is always null int result = cvWriteFrame(writer, img_color); NSLog(@"\n%d",result); //hence this is also 0 all the time cvReleaseVideoWriter(&writer); } I am not sure about the the second parameter. What sort of codec or what exactly it does... I am a n00B in this. Any suggestions?

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  • How can display gif on a subview in iPhone using glgif?

    - by iPhoney
    I want to display a gif image on a subview in iPhone. The sample code glgif shows the gif image on the controller's root view, but when I make the following modifications, the application just crashes: IBOutlet UIView *gifView; // gifView is added as a subview of controller's root view //PlayerView *plView = (PlayerView *)self.view; PlayerView *plView = (PlayerView *)gifView; // Load test.gif VideoSource NSString *str = [[NSBundle mainBundle] pathForResource:@"test" ofType:@"gif"]; FILE *fp = fopen([str UTF8String], "r"); VideoSource *src = VideoSource_init(fp, VIDEOSOURCE_FILE); src->writeable = false; // Init video using VideoSource Video *vid = [[GifVideo alloc] initWithSource:src inContext:[plView context]]; VideoSource_release(src); // Start if loaded if (vid) { [plView startAnimation:vid]; [vid release]; return; } // Cleanup if failed fclose(fp); Now the app crashes in this line: Video *vid = [[GifVideo alloc] initWithSource:src inContext:[plView context]]; with the error message:-[UIView context]: unrecognized selector sent to instance. Any ideas about how to add the plView to the subview properly?

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  • How can I implement a volume meter for a song currently playing? (iPhone OS 3.1.3)

    - by Adam
    Hi i'm very new to core audio and I just would like some help in coding up a little volume meter for whatever's being outputted through headphones or built-in speaker. Like a dB meter. I have the following code, and have been trying to go through the apple source project "SpeakHere", but it's a nightmare trying to go through all that, without knowing how it works first... Could anyone shed some light? Here's the code I have so far... (void)displayWaveForm { while (musicIsPlaying == YES { NSLog(@"%f",sizeof(AudioQueueLevelMeterState)); } } (IBAction)playMusic { if (musicIsPlaying == NO) { NSURL *url = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/track7.wav",[[NSBundle mainBundle] resourcePath]]]; NSError *error; music = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error]; music.numberOfLoops = -1; music.volume = 0.5; [music play]; musicIsPlaying = YES; [self displayWaveForm]; } else { [music pause]; musicIsPlaying = NO; } }

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  • Delphi: Problems with TList of Frames

    - by Dan Kelly
    I'm having a problem with an interface that consists of a number of frames (normally 25) within a TScrollBox. There are 2 problems, and I am hoping that one is a consequence of the other... Background: When the application starts up, I create 25 frames, each containing approx. 20 controls, which are then populated with the default information. The user can then click on a control to limit the search to a subset of information at which point I free and recreate my frames (as the search may return < 25 records) The problem: If I quit the application after the initial search then it takes approx. 5 seconds to return to Delphi. After the 2nd search (and dispose / recreate of frames) it takes approx. 20 seconds) Whilst I could rewrite the application to only create the frames once, I would like to understand what is going on. Here is my create routine: procedure TMF.CreateFrame(i: Integer; var FrameBottom: Integer); var NewFrame: TSF; begin NewFrame := TSF.Create(Self); NewFrame.Name := 'SF' + IntToStr(i); if i = 0 then NewSF.Top := 8 else NewSF.Top := FrameBottom + 8; FrameBottom := NewFrame.Top + NewFrame.Height; NewFrame.Parent := ScrollBox1; FrameList.Add(NewFrame); end; And here is my delete routine: procedure TMF.ClearFrames; var i: Integer; SF: TSF; begin for i := 0 to MF.FrameList.Count -1 do begin SF := FrameList[i]; SF.Free; end; FrameList.Clear; end; What am I missing?

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  • Where'd my sounds go?

    - by Dane Man
    In my Row class I have the initWithCoder method and everything restored in that method works fine, but only within the method. After the method is called I loose an array of sounds that is in my Row class. The sounds class also has the initWithCoder method, and the sound plays fine but only in the Row class initWithCoder method. After decoding the Row object, the sound array disappears completely and is unable to be called. Here's my source for the initWithCoder: - (id) initWithCoder:(NSCoder *)coder { ... soundArray = [coder decodeObjectForKey:@"soundArray"]; NSLog(@"%d",[soundArray count]); return self; } the log shows the count as 8 like it should (this is while unarchiving). Then the row object I create gets assigned. And the resulting row object no longer has a soundArray. [NSKeyedArchiver archiveRootObject:row toFile:@"DefaultRow"]; ... row = [NSKeyedUnarchiver unarchiveObjectWithFile:@"DefaultRow"]; So now whenever I call the soundArray it crashes. //ERROR IS HERE NSLog(@"%d",[[row soundArray] count]); Help please (soundArray is an NSMutableArray).

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  • Fabric "TypeError: not all arguments converted during string formatting"

    - by Brian Carpio
    I have the following fabric task: @task def deploy_west_ec2_ami(name, puppetClass, size='m1.small', region='us-west-1', basedn='joe', ldap='arch-ldap-01', secret='secret', subnet='subnet-d43b8ab d', sgroup='sg-926578fe'): execute(deploy_ec2_ami, name='%s',puppetClass='%s',size='%s',region='%s',basedn='%s',ldap='%s',secret='%s',subnet='%s',sgroup='%s' %(name, puppetClass , size, region, basedn, ldap, secret, subnet, sgroup)) However when I run the command: fab deploy_west_ec2_ami:test,java I get the following Traceback: Traceback (most recent call last): File "/usr/local/lib/python2.6/dist-packages/fabric/main.py", line 710, in main *args, **kwargs File "/usr/local/lib/python2.6/dist-packages/fabric/tasks.py", line 321, in execute results['<local-only>'] = task.run(*args, **new_kwargs) File "/usr/local/lib/python2.6/dist-packages/fabric/tasks.py", line 113, in run return self.wrapped(*args, **kwargs) File "/home/bcarpio/Projects/githubenterprise/awsdeploy/fabfile.py", line 35, in deploy_west_ec2_ami execute(deploy_ec2_ami, name='%s',puppetClass='%s',size='%s',region='%s',basedn='%s',ldap='%s',secret='%s',subnet='%s',sgroup='%s' %(name, puppetClass, size, region, basedn, ldap, secret, subnet, sgroup)) TypeError: not all arguments converted during string formatting I am not sure I understand why. I am pretty sure I have all the values defined here just fine. Also when I run the execute task deploy_ec2_ami as so: deploy_ec2_ami:test,java,m1.small,us-west-1,'dc\=test\,dc\=net',ldap-01,secret,subnet-d43b8abd,sg-926578fe It works just fine

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  • Can I load a UIImage from a URL?

    - by progrmr
    I have a URL for an image (got it from UIImagePickerController) but I no longer have the image in memory (the URL was saved from a previous run of the app). Can I reload the UIImage from the URL again? I see that UIImage has a imageWithContentsOfFile: but I have a URL. Can I use NSData's dataWithContentsOfURL: to read the URL? EDIT based on @Daniel's answer I tried the following code but it doesn't work... NSLog(@"%s %@", __PRETTY_FUNCTION__, photoURL); if (photoURL) { NSURL* aURL = [NSURL URLWithString:photoURL]; NSData* data = [[NSData alloc] initWithContentsOfURL:aURL]; self.photoImage = [UIImage imageWithData:data]; [data release]; } When I ran it the console shows: -[PhotoBox willMoveToWindow:] file://localhost/Users/gary/Library/Application%20Support/iPhone%20Simulator/3.2/Media/DCIM/100APPLE/IMG_0004.JPG *** -[NSURL length]: unrecognized selector sent to instance 0x536fbe0 *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSURL length]: unrecognized selector sent to instance 0x536fbe0' Looking at the call stack, I'm calling URLWithString, which calls URLWithString:relativeToURL:, then initWithString:relativeToURL:, then _CFStringIsLegalURLString, then CFStringGetLength, then forwarding_prep_0, then forwarding, then -[NSObject doesNotRecognizeSelector]. Any ideas why my NSString (photoURL's address is 0x536fbe0) doesn't respond to length? Why does it say it doesn't respond to -[NSURL length]? Doesn't it know that param is an NSString, not a NSURL?

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  • Objective-C NSDate memory issue (again)

    - by Toby Wilson
    I'm developing a graphing application and am attempting to change the renderer from OpenGL to Quartz2D to make text rendering easier. A retained NSDate object that was working fine before suddenly seems to be deallocating itself, causing a crash when an NSMutableString attempts to append it's decription (now 'nil'). Build & analyse doesn't report any potential problems. Simplified, the code looks like this: NSDate* aDate -(id)init { aDate = [[NSDate date] retain] return self; } -(void)drawRect(CGRect)rect { NSMutableString* stringy = [[NSMutableString alloc] init]; //aDate is now deallocated and pointing at 0x0? [stringy appendString:[aDate description]]; //Crash } I should stress that the actual code is a lot more complicated than that, with a seperate thread also accessing the date object, however suitable locks are in place and when stepping through the code [aDate release] is not being called anywhere. Using [[NSDate alloc] init] bears the same effect. I should also add that init IS the first function to be called. Can anyone suggest something I may have overlooked, or why the NSDate object is (or appears to be) releasing itself?

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  • iPhone: Accessing Composite Name in AddressBook Causes EXC_BAD_ACCESS

    - by Fyrian
    Hi everyone. I'm new to iPhone development and have a question I hope someone can help me with. I have a programmer working on an iPhone app for me and when I run the app in the simulator, it works great. But when I try to run it on my actual iPhone, I get a EXC_BAD_ACCESS error and the app locks up. Looking at the debugger, it's referencing the following code in my MainController as the problem: -(void)loadAddressBook{ NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; addressBookLoaded=1; [AddressbookRecord readAllContactTable:[self getDBPath]]; ABAddressBookRef addressBook = ABAddressBookCreate(); for(NSUInteger i=1;i<=ABAddressBookGetPersonCount(addressBook);i++) { ABRecordRef myPerson =ABAddressBookGetPersonWithRecordID (addressBook,(ABRecordID)(i)); NSString *name = (NSString*)ABRecordCopyCompositeName(myPerson); //save in database AddressbookRecord *addObj = [[AddressbookRecord alloc] initWithPrimaryKey:0]; addObj.ClientName=name; [addObj addNewContactEntry]; } addressBookLoaded=2; [pool release]; } More specifically, it points to this specific line as the problem: NSString *name =(NSString*)ABRecordCopyCompositeName(myPerson); My programmer can't seem to figure out what the problem is since he can't replicate it on his end. Does anyone have any ideas what would cause this problem??? Thanks!

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  • OpenCV and iPhone

    - by gn-mithun
    Hello, I am writing an application to create a movie file from a bunch of images on an iPhone. I am using OpenCv. I downloaded openCv static libraries for arm(iPhones native instruction architecture) and the libraries were generated just fine. There were no problems linking to them libraries. As a first step, i was trying to create a .avi file using one image, to see if it works. But cvCreateVideoWriter always returns me a NULL value. I did some searchin and i believe its due to the codec not being present. I am trying this on the iPhone simulator. this is what i do... (void)viewDidLoad { [super viewDidLoad]; UIImage *anImage = [UIImage imageNamed:@"1.jpg"]; IplImage *img_color = [self CreateIplImageFromUIImage:anImage]; //The image gets created just fine CvVideoWriter *writer = cvCreateVideoWriter("out.avi",CV_FOURCC('P','I','M','1'), 25,cvSize(320,480),1); //writer is always null int result = cvWriteFrame(writer, img_color); NSLog(@"\n%d",result); //hence this is also 0 all the time cvReleaseVideoWriter(&writer); } I am not sure about the the second parameter. What sort of codec or what exactly it does... I am a n00B in this. Any suggestions?

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  • loading custom view using loadNibNamed showing memory leaks

    - by user307550
    I have a number of custom table cells and views that I built using interface builder In interface builder, everything is set up similarly. There is a table cell and a couple other UILabels and a background image Object owner if the nib is NSObject Class for the table cell is the name of the class for my table cell Here is how I create the table cell in my code: SectionedSwitchTableCell *cell = nil; NSArray *nibs = [[NSBundle mainBundle] loadNibNamed:kSectionedSwitchTableCellIdentifier owner:owner options:nil]; for(id currentObject in nibs) { if([currentObject isKindOfClass:[SectionedSwitchTableCell class]]) { cell = (SectionedSwitchTableCell *)currentObject; break; } } return cell; For my custom table headers I have this NSArray *nibs = [[NSBundle mainBundle] loadNibNamed:@"CustomTableHeader" owner:self options:nil]; for(id currentObject in nibs) { if([currentObject isKindOfClass:[CustomTableHeader class]]) { return header } } In my .h and .m files for the custom view, I have IBOutlet, @property set up for everything except for the background image UIImageView. Everything that has the IBOutlet and @property are also @synthesized and released in the .m file. Leaks is showing that I have memory leaks with CALayer when I create these custom view objects. Am I doing something wrong here when I create these custom view objects? I'm kind of tearing my hair out trying to figure out where these leaks are coming from. As a side note, I have a UIImageView background image defined in these custom views but I didn't define properties and IBOutlets in my .h and .m files. Defining them doesn't make a difference when I run it through Leaks but just wanted to confirm if I'm doing the right thing. Any input would be super helpful. Thanks :)

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  • What's the standard convention for creating a new NSArray from an existing NSArray?

    - by Prairiedogg
    Let's say I have an NSArray of NSDictionaries that is 10 elements long. I want to create a second NSArray with the values for a single key on each dictionary. The best way I can figure to do this is: NSMutableArray *nameArray = [[NSMutableArray alloc] initWithCapacity:[array count]]; for (NSDictionary *p in array) { [nameArray addObject:[p objectForKey:@"name"]]; } self.my_new_array = array; [array release]; [nameArray release]; } But in theory, I should be able to get away with not using a mutable array and using a counter in conjunction with [nameArray addObjectAtIndex:count], because the new list should be exactly as long as the old list. Please note that I am NOT trying to filter for a subset of the original array, but make a new array with exactly the same number of elements, just with values dredged up from the some arbitrary attribute of each element in the array. In python one could solve this problem like this: new_list = [p['name'] for p in old_list] or if you were a masochist, like this: new_list = map(lambda p: p['name'], old_list) Having to be slightly more explicit in objective-c makes me wonder if there is an accepted common way of handling these situations.

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  • Why is there no autorelease pool when I do performSelectorInBackground: ?

    - by Thanks
    I am calling a method that goes in a background thread: [self performSelectorInBackground:@selector(loadViewControllerWithIndex:) withObject:[NSNumber numberWithInt:viewControllerIndex]]; then, I have this method implementation that gets called by the selector: - (void) loadViewControllerWithIndex:(NSNumber *)indexNumberObj { NSAutoreleasePool *arPool = [[NSAutoreleasePool alloc] init]; NSInteger vcIndex = [indexNumberObj intValue]; Class c; UIViewController *controller = [viewControllers objectAtIndex:vcIndex]; switch (vcIndex) { case 0: c = [MyFirstViewController class]; break; case 1: c = [MySecondViewController class]; break; default: NSLog(@"unknown index for loading view controller: %d", vcIndex); // error break; } if ((NSNull *)controller == [NSNull null]) { controller = [[c alloc] initWithNib]; [viewControllers replaceObjectAtIndex:vcIndex withObject:controller]; [controller release]; } if (controller.view.superview == nil) { UIView *placeholderView = [viewControllerPlaceholderViews objectAtIndex:vcIndex]; [placeholderView addSubview:controller.view]; } [arPool release]; } Althoug I do create an autorelease pool there for that thread, I always get this error: 2009-05-30 12:03:09.910 Demo[1827:3f03] *** _NSAutoreleaseNoPool(): Object 0x523e50 of class NSCFNumber autoreleased with no pool in place - just leaking Stack: (0x95c83f0f 0x95b90442 0x28d3 0x2d42 0x95b96e0d 0x95b969b4 0x93a00155 0x93a00012) If I take away the autorelease pool, I get a whole bunch of messages like these. I also tried to create an autorelease pool around the call of the performSelectorInBackground:, but that doesn't help. I suspect the parameter, but I don't know why the compiler complains about an NSCFNumber. Am I missing something? My Instance variables are all "nonatomic". Can that be a problem? UPDATE: I may also suspect that some variable has been added to an autorelease pool of the main thread (maybe an ivar), and now it trys to release that one inside the wrong autorelease pool? If so, how could I fix that? (damn, this threading stuff is complex ;) )

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  • Using ember-resource with couchdb - how can i save my documents?

    - by Thomas Herrmann
    I am implementing an application using ember.js and couchdb. I choose ember-resource as database access layer because it nicely supports nested JSON documents. Since couchdb uses the attribute _rev for optimistic locking in every document, this attribute has to be updated in my application after saving the data to the couchdb. My idea to implement this is to reload the data right after saving to the database and get the new _rev back with the rest of the document. Here is my code for this: // Since we use CouchDB, we have to make sure that we invalidate and re-fetch // every document right after saving it. CouchDB uses an optimistic locking // scheme based on the attribute "_rev" in the documents, so we reload it in // order to have the correct _rev value. didSave: function() { this._super.apply(this, arguments); this.forceReload(); }, // reload resource after save is done, expire to make reload really do something forceReload: function() { this.expire(); // Everything OK up to this location Ember.run.next(this, function() { this.fetch() // Sub-Document is reset here, and *not* refetched! .fail(function(error) { App.displayError(error); }) .done(function() { App.log("App.Resource.forceReload fetch done, got revision " + self.get('_rev')); }); }); } This works for most cases, but if i have a nested model, the sub-model is replaced with the old version of the data just before the fetch is executed! Interestingly enough, the correct (updated) data is stored in the database and the wrong (old) data is in the memory model after the fetch, although the _rev attribut is correct (as well as all attributes of the main object). Here is a part of my object definition: App.TaskDefinition = App.Resource.define({ url: App.dbPrefix + 'courseware', schema: { id: String, _rev: String, type: String, name: String, comment: String, task: { type: 'App.Task', nested: true } } }); App.Task = App.Resource.define({ schema: { id: String, title: String, description: String, startImmediate: Boolean, holdOnComment: Boolean, ..... // other attributes and sub-objects } }); Any ideas where the problem might be? Thank's a lot for any suggestion! Kind regards, Thomas

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  • Can parser combinators be made efficient?

    - by Jon Harrop
    Around 6 years ago, I benchmarked my own parser combinators in OCaml and found that they were ~5× slower than the parser generators on offer at the time. I recently revisited this subject and benchmarked Haskell's Parsec vs a simple hand-rolled precedence climbing parser written in F# and was surprised to find the F# to be 25× faster than the Haskell. Here's the Haskell code I used to read a large mathematical expression from file, parse and evaluate it: import Control.Applicative import Text.Parsec hiding ((<|>)) expr = chainl1 term ((+) <$ char '+' <|> (-) <$ char '-') term = chainl1 fact ((*) <$ char '*' <|> div <$ char '/') fact = read <$> many1 digit <|> char '(' *> expr <* char ')' eval :: String -> Int eval = either (error . show) id . parse expr "" . filter (/= ' ') main :: IO () main = do file <- readFile "expr" putStr $ show $ eval file putStr "\n" and here's my self-contained precedence climbing parser in F#: let rec (|Expr|) (P(f, xs)) = Expr(loop (' ', f, xs)) and loop = function | ' ' as oop, f, ('+' | '-' as op)::P(g, xs) | (' ' | '+' | '-' as oop), f, ('*' | '/' as op)::P(g, xs) -> let h, xs = loop (op, g, xs) let op = match op with | '+' -> (+) | '-' -> (-) | '*' -> (*) | '/' -> (/) loop (oop, op f h, xs) | _, f, xs -> f, xs and (|P|) = function | '('::Expr(f, ')'::xs) -> P(f, xs) | c::xs when '0' <= c && c <= '9' -> P(int(string c), xs) My impression is that even state-of-the-art parser combinators waste a lot of time back tracking. Is that correct? If so, is it possible to write parser combinators that generate state machines to obtain competitive performance or is it necessary to use code generation?

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  • Cross-reference js-object variables when creating object

    - by Ivar Bonsaksen
    Summary: I want to know if it is possible to do something like this: {a: 'A',b: this.a} ...by using some other pointer like {a: 'A',b: self.a} or {a: 'A',b: own.a} or anything else... Full question: I'm trying to extend MyBaseModule using Ext.extend, and need to cross-reference values in the extension object passed to Ext.extend(). Since I'm not yet in context of MyModule, I'm not able to use this to reference the object (See example below line 12). Is there any other way to reference values like this without creating the object first? 1 MyModule = Ext.extend(MyBaseModule, { 2 dataStores: { 3 myDataStore: new Ext.data.Store({...}) 4 }, 5 6 myGridDefinition: { 7 id: 'myGridDefinitionPanel', 8 bodyBorder: false, 9 items: [{ 10 xtype: 'grid', 11 id: 'myGridDefinitionGrid', 12 store: this.dataStores.myDataStore 13 }] 14 } 15 }); Or is the following the only solution? I would like to avoid this if possible, as I find it less readable for large extension definitions. 1 var extensionObject = { 2 dataStores: { 3 myDataStore: new Ext.data.Store({...}) 4 }, 5 6 myGridDefinition: { 7 id: 'myGridDefinitionPanel', 8 bodyBorder: false, 9 items: [{ 10 xtype: 'grid', 11 id: 'myGridDefinitionGrid' 12 }] 13 } 14 }; 15 16 extensionObject.locationsGrid.items[0].store = extensionObject.dataStores.locations; 17 18 MyModule = Ext.extend(MyBaseModule, extensionObject);

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  • How to get the title and subtitle for a pin when we are implementing the MKAnnotation?

    - by wolverine
    I have implemented the MKAnnotation as below. I will put a lot of pins and the information for each of those pins are stored in an array. Each member of this array is an object whose properties will give the values for the title and subtitle of the pin. Each object corresponds to a pin. But how can I display these values for the pin when I click a pin?? @interface UserAnnotation : NSObject <MKAnnotation> { CLLocationCoordinate2D coordinate; NSString *title; NSString *subtitle; NSString *city; NSString *province; } @property (nonatomic, assign) CLLocationCoordinate2D coordinate; @property (nonatomic, retain) NSString *title; @property (nonatomic, retain) NSString *subtitle; @property (nonatomic, retain) NSString *city; @property (nonatomic, retain) NSString *province; -(id)initWithCoordinate:(CLLocationCoordinate2D)c; And .m is @implementation UserAnnotation @synthesize coordinate, title, subtitle, city, province; - (NSString *)title { return title; } - (NSString *)subtitle { return subtitle; } - (NSString *)city { return city; } - (NSString *)province { return province; } -(id)initWithCoordinate:(CLLocationCoordinate2D)c { coordinate=c; NSLog(@"%f,%f",c.latitude,c.longitude); return self; } @end

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  • Python and Unicode: How everything should be Unicode

    - by A A
    Forgive if this a long a question: I have been programming in Python for around six months. Self taught, starting with the Python tutorial and then SO and then just using Google for stuff. Here is the sad part: No one told me all strings should be Unicode. No, I am not lying or making this up, but where does the tutorial mention it? And most examples also I see just make use of byte strings, instead of Unicode strings. I was just browsing and came across this question on SO, which says how every string in Python should be a Unicode string. This pretty much made me cry! I read that every string in Python 3.0 is Unicode by default, so my questions are for 2.x: Should I do a: print u'Some text' or just print 'Text' ? Everything should be Unicode, does this mean, like say I have a tuple: t = ('First', 'Second'), it should be t = (u'First', u'Second')? I read that I can do a from __future__ import unicode_literals and then every string will be a Unicode string, but should I do this inside a container also? When reading/ writing to a file, I should use the codecs module. Right? Or should I just use the standard way or reading/ writing and encode or decode where required? If I get the string from say raw_input(), should I convert that to Unicode also? What is the common approach to handling all of the above issues in 2.x? The from __future__ import unicode_literals statement? Sorry for being a such a noob, but this changes what I have been doing for a long time and so clearly I am confused.

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  • iPhone application update (using Core Data on Sqlite)

    - by owen
    I have an app which is using Core Data on Sqlite, Now I have a update which has some DB structure changes say adding a new table I know when an app get updated, it updates the app binary only, nothing on document directory will be changed. When the app gets updated and launchs at the first time and run [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]]; It will find the difference between the data model and DB structure in Sqlite and will throw an exception and quit. Error: "The model used to open the store is incompatible with the one used to create the store" So, can anyone here give me some idea how to update an app when there is a DB structure change? I think we can run a DB script to create that new table when it launchs the update at the first time. But if there are other changes like changing the type of some fields or deleting some fields, and we need to migrate the old data, this is really a headache. In this case, Is the only way to do is creating a new app? Is there anyone tried something similar like this?

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  • ActiveRecord exceptions not rescued

    - by zoopzoop
    I have the following code block: unless User.exist?(...) begin user = User.new(...) # Set more attributes of user user.save! rescue ActiveRecord::RecordInvalid, ActiveRecord::RecordNotUnique => e # Check if that user was created in the meantime user = User.exists?(...) raise e if user.nil? end end The reason is, as you can probably guess, that multiple processes might call this method at the same time to create the user (if it doesn't already exist), so while the first one enters the block and starts initializing a new user, setting the attributes and finally calling save!, the user might already be created. In that case I want to check again if the user exists and only raise the exception if it still doesn't (= if no other process has created it in the meantime). The problem is, that regularly ActiveRecord::RecordInvalid exceptions are raised from the save! and not rescued from the rescue block. Any ideas? EDIT: Alright, this is weird. I must be missing something. I refactored the code according to Simone's tip to look like this: unless User.find_by_email(...).present? # Here we know the user does not exist yet user = User.new(...) # Set more attributes of user unless user.save # User could not be saved for some reason, maybe created by another request? raise StandardError, "Could not create user for order #{self.id}." unless User.exists?(:email => ...) end end Now I got the following exception: ActiveRecord::RecordNotUnique: Mysql::DupEntry: Duplicate entry '[email protected]' for key 'index_users_on_email': INSERT INTO `users` ... thrown in the line where it says 'unless user.save'. How can that be? Rails thinks the user can be created because the email is unique but then the Mysql unique index prevents the insert? How likely is that? And how can it be avoided?

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  • Add Keyboard Binding To Existing Emacs Mode

    - by Sean M
    I'm attempting my first modification of emacs. I recorded a little keyboard macro and had emacs spit it out as elisp, resulting in: (setq add-docstring "\C-rdef\C-n\C-a\C-m\C-p\C-i\C-u6\"\C-u3\C-b") (global-set-key "\C-c\C-d" 'add-docstring) Searching the emacs reference, though, revealed that C-c C-d is already bound in diff mode. I don't plan on using diff mode, but the future is unknowable and I'd like to not lay a trap for myself. So I'd like this keybinding to only operate in python mode, where it tries to help me add docstrings. In my /usr/share/emacs/23.whatever/list/progmodes, I found python.elc and python.el.gz. I unzipped python.el.gz and got a readable version of the elisp file. Now, though, the documentation becomes opaque to me. How can I add my key binding to the python mode, instead of globally? Is it possible, for bonus points, to apply the changes to python mode without restarting emacs or closing open files? It's the self-modifying editor, I figure there's a good chance that it's possible.

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  • Malware - Technical anlaysis

    - by nullptr
    Note: Please do not mod down or close. Im not a stupid PC user asking to fix my pc problem. I am intrigued and am having a deep technical look at whats going on. I have come across a Windows XP machine that is sending unwanted p2p traffic. I have done a 'netstat -b' command and explorer.exe is sending out the traffic. When I kill this process the traffic stops and obviously Windows Explorer dies. Here is the header of the stream from the Wireshark dump (x.x.x.x) is the machines IP. GNUTELLA CONNECT/0.6 Listen-IP: x.x.x.x:8059 Remote-IP: 76.164.224.103 User-Agent: LimeWire/5.3.6 X-Requeries: false X-Ultrapeer: True X-Degree: 32 X-Query-Routing: 0.1 X-Ultrapeer-Query-Routing: 0.1 X-Max-TTL: 3 X-Dynamic-Querying: 0.1 X-Locale-Pref: en GGEP: 0.5 Bye-Packet: 0.1 GNUTELLA/0.6 200 OK Pong-Caching: 0.1 X-Ultrapeer-Needed: false Accept-Encoding: deflate X-Requeries: false X-Locale-Pref: en X-Guess: 0.1 X-Max-TTL: 3 Vendor-Message: 0.2 X-Ultrapeer-Query-Routing: 0.1 X-Query-Routing: 0.1 Listen-IP: 76.164.224.103:15649 X-Ext-Probes: 0.1 Remote-IP: x.x.x.x GGEP: 0.5 X-Dynamic-Querying: 0.1 X-Degree: 32 User-Agent: LimeWire/4.18.7 X-Ultrapeer: True X-Try-Ultrapeers: 121.54.32.36:3279,173.19.233.80:3714,65.182.97.15:5807,115.147.231.81:9751,72.134.30.181:15810,71.59.97.180:24295,74.76.84.250:25497,96.234.62.221:32344,69.44.246.38:42254,98.199.75.23:51230 GNUTELLA/0.6 200 OK So it seems that the malware has hooked into explorer.exe and hidden its self quite well as a Norton Scan doesn't pick anything up. I have looked in Windows firewall and it shouldn't be letting this traffic through. I have had a look into the messages explorer.exe is sending in Spy++ and the only related ones I can see are socket connections etc... My question is what can I do to look into this deeper? What does malware achieve by sending p2p traffic? I know to fix the problem the easiest way is to reinstall Windows but I want to get to the bottom of it first, just out of interest.

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