I'm trying to save an NSMutableArray called queueArray so it can be loaded again after the app has been quit. I used a few tutorials to get me going and this is the code I have come up with. The problem seems to be that "initWithCoder" and "encodeWithCoder" are not being called, shown by no NSLog calls and no stopping at breakpoints. I have added the NSCoding protocol to the .h file and I know that queueArray is not nil and it contains MPMediaItems. Here is some of the code I use to try to save and load the array:
-(IBAction)saveQueuePressed {
NSString *rootPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *filePath = [rootPath stringByAppendingPathComponent:#"queueArray.archive"];
//should cause encodeWithCoder to be called
[NSKeyedArchiver archiveRootObject:queueArray toFile:filePath];
}
-(IBAction)loadQueuePressed {
NSString *rootPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *filePath = [rootPath stringByAppendingPathComponent:#"queueArray.archive"];
//should cause initWithCoder to be called
queueArray = [NSKeyedUnarchiver unarchiveObjectWithFile:filePath];
}
-(void)encodeWithCoder:(NSCoder *)coder {
NSLog(#"encodeWithCoder");
[coder encodeObject:queueArray forKey:#"savedQueueArray"];
}
-(id)initWithCoder:(NSCoder *)decoder {
NSLog(#"initWithCoder");
queueArray = [decoder decodeObjectForKey:#"savedQueueArray"];
return self;
}
Any help will be greatly appreciated!
The encodeWithCoder: and initWithCoder methods are called when you archive/unarchive an object that responds to them. From what I understand, you have those methods in your class, but the object you are actually archiving (queueArray) is not an instance of that class, it's an NSMutableArray.
If you do want to save your entire object, you can change your saveQueue method to this
-(IBAction)saveQueuePressed {
NSString *rootPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *filePath = [rootPath stringByAppendingPathComponent:#"queueArray.archive"];
// saving the array shouldn't, but saving the self object
//should cause encodeWithCoder to be called:
[NSKeyedArchiver archiveRootObject:self toFile:filePath];
}
But if you just want to save the array, I guess you can just use saveQueuePressed and loadQueuePressed, I don't think you need the encode/init WithCoder: methods
Update:
Maybe your path is not right.
Try
NSString *rootPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *filePath = [[rootPath stringByAppendingPathComponent:#"queueArray.archive"] stringByExpandingTildeInPath]];
Filipe is right! Your comment said you still didn't use his method.
I had this issue too. Switching from the dictionary's atomic write method to the keyedArchiver fixed it, luckily I only had to change one thing, the line that said writeToFile: is now the archive function.
Now my program's working. For some reason, even when responding to NSCoding, the custom object is not being encoded and breaks my dictionary. Is this a bug with iOS? I've read a fair number of Apple Manuals, but I've also seen a fair number of typos and missing info (For example, try MKMapRect functions without the videos to explain them), or Core Animations referencing the Run Loop before you learn threading, I could go on, half finished sentences in Quartz... so yeah, I've read the manuals and this perplexes me, we have to get a more open iOS SDK at some point, hopefully
Related
I'm working on an OSX application where I need to store 446 CGLayers that get placed in a PDF context and am wondering if there's a way to write and read them from a file, rather than generating them when the application loads
I've read that CGLayer is no longer recommended, but I feel they really fit what I need. Also, if I use bitmapGraphicsContexts, they can pixelate when zooming in.
I am able to store them in NSArrays, both by storing them in NSValue and puting them into the array by bridging. I've also tried storing them in C arrays, but that didn't work out.
My problem comes when trying to store these arrays in a file. writeToFile: doesn't work with CGLayers, but NSKeyedArchiver/NSKeyedUnarchiver hasn't worked either, both when the layers are in NSValues or bridged.
Here's my method that attempts to write and read an array containing a single layer from a file.
+(CGLayerRef) colorAnnotations:(CGContextRef)context{
float symbolSize = 8;
CGRect glyphBox = CGRectMake(0,0, 8, 8);
CGLayerRef annotationLayer = CGLayerCreateWithContext (context,glyphBox.size, NULL);
CGContextRef annotaionLayerContext = CGLayerGetContext(annotationLayer);
CGMutablePathRef annot = CGPathCreateMutable();
//Drawing annotation
/*...*/
NSMutableArray *test = [[NSMutableArray alloc]init];
[test addObject:[[NSValue alloc] initWithBytes:&annotationLayer objCType:#encode(CGLayerRef)]];
//Getting file path in Documents directory
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *dataPath = [documentsDirectory stringByAppendingPathComponent:#"/annots.data"];
[NSKeyedArchiver archiveRootObject:test toFile:dataPath];
NSMutableArray *testLoads = [NSKeyedUnarchiver unarchiveObjectWithFile:dataPath];
CGLayerRef layerToReturn;
[[testLoads objectAtIndex:0]getValue:&layerToReturn];
return layerToReturn;
}
I get [NSKeyedArchiver encodeValueOfObjCType:at:]: unknown type encoding ('^')') was raisedfrom this, pretty sure because of the CGLayerRef type.
The lines needed to draw the different annotations I need are pretty long, so I've been trying to figure out a way to have them made and stored in a file without having to make them on startup each time. So far I'm not seeing a way to do this, but was hoping someone here may know of one and would appreciate any help.
I have a NSString that should be constant in my class. I used the following code to accomplish this:
#interface DefinitionViewController ()
#end
static NSString *preamble;
#implementation DefinitionViewController {
}
+(void)initialize {
if (self == [DefinitionViewController class]) {
NSString *path = [[NSBundle mainBundle] pathForResource:#"preamble" ofType:#"html"];
preamble = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding
error:nil];
}
}
It seems to work fine. I worry about using a file read inside an initialize. Is there a more appropriate means to accomplish the same goal (shared static string)? I could bury this inside my code, but it was much easier to maintain the somewhat large string as an external file.
Thanks for any advice.
"I worry about using a file read inside an initialize".
Don't (worry). The fact that it is, for example, a class method is utterly irrelevant. It is code. It runs and does its job. It is sound code, it runs coherently at a coherent time, and your app bundle is a real thing that really contains the resource. There's no problem here.
If you want to postpone creation of the string, and make assurance doubly sure that the string is not initialized twice, you could instead use a singleton pattern so that the string value is not generated until the first time it is explicitly requested:
+ (NSString*) preamble {
static NSString* preamble = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
NSString *path = [[NSBundle mainBundle] pathForResource:#"preamble" ofType:#"html"];
preamble = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
});
return preamble;
}
But there is no special need for this. (EDIT: But see, to the contrary, the comment below of #bbum, who Really Knows Stuff.)
I'm trying to upload an image to dropbox. I'm using the latest version of the SDK (Sept. 17) and have successfully authenticated my app.
Here's the code that does it:
for ( NSUInteger i = 0; i < [photos count]; i ++ ) {
NSString *filename = [NSString stringWithFormat:#"%d.png", i+1];
NSString *file = [NSTemporaryDirectory() stringByAppendingPathComponent:filename];
[UIImagePNGRepresentation([photos objectAtIndex:i]) writeToFile:file atomically:YES];
NSString *destDir = #"/";
[self.dropboxClient uploadFile:filename toPath:destDir withParentRev:nil fromPath:file];
}
Note:
self.dropboxClient is an instanced DBRestClient object.
photos is an NSMutableArray of UIImages (I already checked to make sure that the objects are images using the NSStringFromClass() method on each object in the list);
Most importantly, I think there may be an issue with my DBRestClient object (self.dropboxClient), since none of the delegate methods are entered even though I've set the delegate.
Any and all help would be greatly appreciated!
This was a threading issue. DBRestClient methods, like createFolder and uploadFile:::: must be executed on the main thread.
I am still searching for a way to solve my memory leaks. For the moment I have a leak at this line of code.
return [UIImage imageWithContentsOfFile:path];
Anybody an idea?
Thx in advance!
- (UIImage *)imageAtIndex:(NSUInteger)index {
// use "imageWithContentsOfFile:" instead of "imageNamed:" here to avoid caching our images
NSString *imageName = [self imageNameAtIndex:index];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *path = [[paths objectAtIndex:0] stringByAppendingPathComponent:imageName];
//NSString *path = [[NSBundle mainBundle] pathForResource:imageName ofType:#"jpg"];
return [UIImage imageWithContentsOfFile:path];
}
- (void)configurePage:(ImageScrollView *)page forIndex:(NSUInteger)index
{
page.index = index;
page.frame = [self frameForPageAtIndex:index];
// To use full images instead of tiled images, replace the "displayTiledImageNamed:" call
// above by the following line:
// [page displayImage:[self imageAtIndex:index]];
[page displayImage:[self imageAtIndex:index]];
}
When leaks identifies a line of code as being a leak, it is not claiming that said line of code is the actual leak. Only that said line of code is the source of the allocation that was leaked.
Thus, the image returned by imageWithContentsOfFile: is being over-retained somewhere else and it is your job to find out where.
Which is generally pretty easy; turn on the "retain tracking" [IIRC] checkbox on the little configuration panel of the Allocations instrument, run your app, and then click through one of the leaked UIImages to see a list of exactly where the image was retained and released. One of those retains will not be balanced and that is your leak.
Though slightly orthogonal, I describe how to do this in a post about using Heapshot Analyais to find leaks.
I have a problem with NSFileManager, because i only can store a file into Application Documents Directory, but i want to create a file into a sub directory this i don't think why, i couldn't create. my code below:
+(NSString *)applicationDocumentsDirectory {
return [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
}
+(BOOL)storeFile:(NSData*)file withName:(NSString*)name atDirectory:(NSString*)dir{
NSFileManager *filemgr;
NSString *docsDir;
NSString *newDir;
BOOL create=NO;
filemgr =[NSFileManager defaultManager];
docsDir = [StorageManager applicationDocumentsDirectory];
newDir = [docsDir stringByAppendingPathComponent:dir];
if(![filemgr fileExistsAtPath:newDir]){
if([filemgr createDirectoryAtPath:newDir withIntermediateDirectories:NO attributes:nil error:nil]){
create=YES;
}
}else
create=YES;
if(create){
if(![filemgr createFileAtPath:newDir contents:file attributes:nil]){
[filemgr release];
return YES;
}
}
[filemgr release];
return NO;
}
I am not sure why the file is not created. At first glance, it looks like your code should work. But I may be overlooking something. It also depends on what exactly you are passing as arguments to the storeFile:withName:atDirectory: method.
Nevertheless I am posting an answer because I did spot another error in your code: you should not send release to filemgr since you also did not send retain to it first and you did not create the object. In this case, there is no need to send retain to it either, since you are only using it locally within your method. You may want to review the Apple Developer Connection document "Cocoa Core Competencies: Memory Management".
I don't think this error explains why the file is not created; though I'm surprised your application doesn't crash because of it.