Why might this code be giving me null? - iphone

Scroll down to EDIT 1. This top bit is irrelevant now.
This is my code:
NSMutableDictionary *dictionary = [self.media objectAtIndex:index];
NSLog(#"dictionary: %#", dictionary);
NSString *originalImagePath = [dictionary objectForKey:#"OriginalImage"];
NSLog(#"path: %#", originalImagePath);
UIImage *originalImage = [UIImage imageWithContentsOfFile:originalImagePath];
NSLog(#"original image: %#", originalImage);
return originalImage;
And my NSLog:
dictionary: {
IsInPhotoLibrary = 1;
MediaType = 0;
OriginalImage = "/var/mobile/Applications/5E25F369-9E05-4345-A0A2-381EDB3321B8/Documents/Images/E9904811-B463-4374-BD95-4AD472DC71A6.jpg";
}
path: /var/mobile/Applications/5E25F369-9E05-4345-A0A2-381EDB3321B8/Documents/Images/E9904811-B463-4374-BD95-4AD472DC71A6.jpg
original image: (null)
Any ideas why this might be coming out as null, despite everything appearing to be in place?
EDIT:
This is the code to write the image to file:
+(NSString *)writeImageToFile:(UIImage *)image {
NSData *fullImageData = UIImageJPEGRepresentation(image, 1.0f);
NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:#"Documents/Images/"];
NSString *name = [NSString stringWithFormat:#"%#.jpg", [JEntry generateUuidString]];
NSString *filePath = [path stringByAppendingPathComponent:name];
[fullImageData writeToFile:filePath atomically:YES];
NSLog(#"original image 2: %#", [UIImage imageWithContentsOfFile:filePath]);
}
This NSLog also comes out as null. So the problem lies here, most likely. Any ideas?
EDIT 2:
So, back-tracing even more now, and I've realised that it's because this fails:
[fullImageData writeToFile:filePath atomically:YES];
You can return a bool on that line, telling if it was successful or not, and it's returning NO for me. Any ideas why this might be?
EDIT 3:
The image that gets passed in is NULL. Trying to figure out where that's gone wrong now.

Almost certainly your file does not exist. Modify your code as follows to log if a file exists or not:
NSString *originalImagePath = [dictionary objectForKey:#"OriginalImage"];
NSLog(#"path: %#", originalImagePath);
BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:originalImagePath];
NSLog(#"file exists: %d", fileExists);

Possible Reasons:
The file at originalImagePath does not exist.
UIImage can not initialize an image from the specified file, because the data is corrupted (maybe the data is empty or incomplete)
the file can not be accessed because of iOS file permissions (i.e. when accessing files beyond the app sandbox)

Have you checked that the image file is really placed on path in dictionary? You may use the iExplorer utility for that.
Also pay attention to the file name case, so it's extension is 'jpg' not 'JPG'.
Finally you should check, whether it's a valid image file, by opening it with some image viewer.

are you sure that the jpg file "E9904811-B463-4374-BD95-4AD472DC71A6.jpg" is there in that folder?
try to open the app file installed in the iPhone/ipad simulator clicking on yourFile.app
with ctrl key and choose to open package contents the open your folder images...
to get a fast link to your documents folder:
NSArray *dirPaths;
NSString *docsDir;
dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
docsDir = [dirPaths objectAtIndex:0];
NSLog(#"doc:%#",docsDir);
your app should be in its parent folder

Related

is saving in NSDocumentDirectory okay?

My app is using the NSDocumentDirectory to save images in it, I just wanna ask if its the safe way to save images(100 maximum). I have read several thread & questions with answers about it, though I dont know which to follow.Some say that its okay to save there. Some say I shouldnt use NSDocumentDirectory for saving, because it will be back-up by the iCloud. So where can I save it that when the user exit the app then run the app again, then images should still be there?. I dont know much about the tmp directory or cache directory. But if its either one of the 2 that I should use, How can I use them in my code here:
NSArray *paths = NSSearchPathForDirectoriesInDomains( NSDocumentDirectory, NSUserDomainMask ,YES );
NSString *documentsDir = [paths objectAtIndex:0];
NSString *savedImagePath = [documentsDir stringByAppendingPathComponent:[NSString stringWithFormat:#"Images%d.png", i]];
ALAssetRepresentation *rep = [[info objectAtIndex: i] defaultRepresentation];
UIImage *image = [UIImage imageWithCGImage:[rep fullResolutionImage]];
//----resize the images
image = [self imageByScalingAndCroppingForSize:image toSize:CGSizeMake(256,256*image.size.height/image.size.width)];
NSData *imageData = UIImagePNGRepresentation(image);
[imageData writeToFile:savedImagePath atomically:YES];
Thank you so much for the help.
The tmp and cache directories are periodically cleaned up by iOS. If the images are for general use, use the camera roll as the other two answers suggest. However if these images are intended just for the scope of your app, you can still safely store them in the Documents directory, you just have to include an "exclude from iCloud backup" function call to each file after saving, in order to prevent Apple rejecting your app for using too much iCloud space. Of course there's a trade-off, disabling this means the user will lose their photos anyway should they delete the app or get another device(etc), but this caveat is preferable to not getting the App on the store at all.
To disable iCloud backup on a file, there's two methods for iOS versions > 5.0:
UPDATE! MERGED BOTH METHODS INTO A SINGLE FUNCTION THAT AUTOMATICALLY HANDLES iOS VERSION:
#include <sys/xattr.h> // Needed import for setting file attributes
+(BOOL)addSkipBackupAttributeToItemAtURL:(NSURL *)fileURL {
// First ensure the file actually exists
if (![[NSFileManager defaultManager] fileExistsAtPath:[fileURL path]]) {
NSLog(#"File %# doesn't exist!",[fileURL path]);
return NO;
}
// Determine the iOS version to choose correct skipBackup method
NSString *currSysVer = [[UIDevice currentDevice] systemVersion];
if ([currSysVer isEqualToString:#"5.0.1"]) {
const char* filePath = [[fileURL path] fileSystemRepresentation];
const char* attrName = "com.apple.MobileBackup";
u_int8_t attrValue = 1;
int result = setxattr(filePath, attrName, &attrValue, sizeof(attrValue), 0, 0);
NSLog(#"Excluded '%#' from backup",fileURL);
return result == 0;
}
else if (&NSURLIsExcludedFromBackupKey) {
NSError *error = nil;
BOOL result = [fileURL setResourceValue:[NSNumber numberWithBool:YES] forKey:NSURLIsExcludedFromBackupKey error:&error];
if (result == NO) {
NSLog(#"Error excluding '%#' from backup. Error: %#",fileURL, error);
return NO;
}
else { // Succeeded
NSLog(#"Excluded '%#' from backup",fileURL);
return YES;
}
} else {
// iOS version is below 5.0, no need to do anything
return YES;
}
}
If your app must support 5.0, then unfortunately your only option is to save those photos in the Caches directory, which means they won't be backed up (this not causing an App Store rejection for that reason), but whenever the storage watchdog decides it's time to clean the Caches folder, you'll lose those photos. Not an ideal implementation at all, but such is the nature of the beast in 5.0, where Apple added in Backup exclusion as an afterthought.
EDIT: Forgot to answer the 'how to save to the tmp/cache directory' part of the question. If you do decide to go down that path:
Saving to tmp:
NSString *tempDir = NSTemporaryDirectory();
NSString *savedImagePath = [tempDir stringByAppendingPathComponent:[NSString stringWithFormat:#"Images%d.png", i]];
(note that this won't appear to have any effect in the simulator, but it works as expected on device)
Saving to Cache:
NSString *cacheDir = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory,NSUserDomainMask,YES)lastObject];
NSString *savedImagePath = [cacheDir stringByAppendingPathComponent:[NSString stringWithFormat:#"Images%d.png", i]];
If you want the user to be able to use the images in other apps or view them along with their photos, use the photo album as Mike D suggest. If the files are something you generate locally for use with your app only, then you should probably use the documents directory. You can expose the documents directory to iTunes with the info.plist option "Application supports iTunes file sharing" which will allow the user to add or delete files through iTunes, but the files will not be exposed to other apps
You are saving scaled images so they are really only useful for your game. They are not going to be very large and will not take up much space. You could save them in the Library directory for the app and avoid the whole iCloud thing, as it doesn't sound like there is any reason to back them up. Also, saving the the Library avoid the possibility of the user deleting them, if for some other reason you have iTunes sharing turned on.
Update: code for saving to the app Library directory
- (void)saveSequences:(NSMutableDictionary*)sequences
{
NSArray *path = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);
NSString *libDirectory = [path objectAtIndex:0];
NSString *settingsPath = [libDirectory stringByAppendingPathComponent:#"userSequences.plist"];
NSLog(#"settingsPath %#", settingsPath);
[sequences writeToFile:settingsPath atomically:YES];
}
// The code below gets the path to a named directory in the 'Documents' folder - and if it doesn't exist, creates it. Adjust it to use the Library path, if you decide to go that route.
- (NSString *)getDirectoryBySequenceName:(NSString *)sequenceName
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString * documentDirectory = [paths objectAtIndex:0];
NSString * sequenceDirectory = [documentDirectory stringByAppendingPathComponent:sequenceName];
NSError *error;
BOOL success = [[NSFileManager defaultManager] createDirectoryAtPath:sequenceDirectory
withIntermediateDirectories:YES
attributes:nil error:&error];
if (!success) {
NSLog(#"Error creating data path: %#", [error localizedDescription]);
}
return sequenceDirectory;
}
Depending on the purpose of your app, you could save it to the photos app (UIImageWriteToSavedPhotosAlbum(image, self, nil, nil) I think, Apple reference). Saving here, or in the documents directory (or any sub folder), will allow the user backup those images to iCloud or iTunes, if the user chooses too and/or if they have set up iCloud.
Since you state the images need to persist between launches, the temp or cache directory get emptied when the application is removed from memory, maybe sooner (the O/S decides).
More about the iOS file system.

Saving in NSDocumentDirectory

Having weird problem with my NSDocumenDirectory saving.
Here is a sneak preview:
First I pick images ( in my imagePickerViewController):
in my PreviewController:
So at first try, it was okay.
Then I revisit the imagePickerViewController to add another image:
in my PreviewController:
This is where the problem occurs. At the image above, it recopies the last image from the old preview (like a duplicate). I dunno what Im doing wrong in my codes. But Im saving it when a file exist. Kindly see:
for (int i = 0; i < info.count; i++) {
NSLog(#"%#", [info objectAtIndex:i]);
NSArray *paths = NSSearchPathForDirectoriesInDomains( NSDocumentDirectory, NSUserDomainMask ,YES );
NSString *documentsDir = [paths objectAtIndex:0];
NSString *savedImagePath = [documentsDir stringByAppendingPathComponent:[NSString stringWithFormat:#"firstSlotImages%d.png", i]];
if ([[NSFileManager defaultManager] fileExistsAtPath:savedImagePath]) {
NSLog(#"file doesnt exist");
} else {
ALAssetRepresentation *rep = [[info objectAtIndex: i] defaultRepresentation];
UIImage *image = [UIImage imageWithCGImage:[rep fullResolutionImage]];
//----resize the images
image = [self imageByScalingAndCroppingForSize:image toSize:CGSizeMake(256,256*image.size.height/image.size.width)];
NSData *imageData = UIImagePNGRepresentation(image);
[imageData writeToFile:savedImagePath atomically:YES];
NSLog(#"saving at:%#",savedImagePath);
}
}
What I need is to just reAdd AGAIN the same image with the new one.
Same as, like the last preview.
The four images are passed in the sequence that they show in the preview, so in the first example the orange cat is third, and in the second example, the orange cat is fourth. The new image isn't saving because it is third, and you already have a file named "firstSlotImages2.png". If you re-save each image without checking if the file exists, you should get the result you are looking for.
There's a key in the media info: UIImagePickerControllerMediaURL which returns an NSURL, convert it to a string and get the the lastPathComponent. Use this as the file name to save to the directory you are saving it to. You can then save the reference to these images by saving this same file name either in an NSMutableArray, or an NSMutableDictionary

Downloading and saving images in iOS

I am creating an iPhone app and in that I want to download multiple image files from web service. And I want to save the images in the local folder in the app itself and save the path to each files in SQLite database. How can I implement this? Please help.
**// Get an image from the URL below**
UIImage *image = [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:#"yorimageurl"]]];
NSLog(#"%f,%f",image.size.width,image.size.height);
**// Let's save the file into Document folder.**
NSString *Dir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *pngPath = [NSString stringWithFormat:#"%#/test.png",Dir];// this path if you want save reference path in sqlite
NSData *data1 = [NSData dataWithData:UIImagePNGRepresentation(image)];
[data1 writeToFile:pngFilePath atomically:YES];
NSLog(#"saving jpeg");
NSString *jpegPath = [NSString stringWithFormat:#"%#/test.jpeg",Dir];// this path if you want save reference path in sqlite
NSData *data2 = [NSData dataWithData:UIImageJPEGRepresentation(image, 1.0f)];//1.0f = 100% quality
[data2 writeToFile:jpegFilePath atomically:YES];
NSLog(#"saving image done");
[image release];
>> Update Additional:
You need to save image name(unique name that you can do early..right..!!) in sqlite database and you can make path or retrieve image using that name as i shown below.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *getImagePath = [documentsDirectory stringByAppendingPathComponent:#"test.png"];// here you jus need to pass image name that you entered when you stored it.
Hope, this will help you...
After implementing #Nit's code.. you can refer This for insert record in database.
This is showing how to insert record in DB. and for getting path read my comments in #Nit's answer.
UPDATE:
For getting path of each downloaded file you have to keep unique name for each file. Now you will have the path where you are writing file that is unique path for every file. Now you simply need to execute insert query every time you download a file or need to save filepath in array and execute query later according to your requirement. Don't forget to give different file name to every file otherwise only single file will be there and your path will be same.
For getting unique filename you can use timestamp:
NSString *fileName = [NSString stringWithFormat:#"%lf.png", [[NSDate date] timeIntervalSince1970];
UPDATE2:
You have path now like: /Users/John/Library/Application Support/iPhone Simulator/5.1/Applications/84A837AA-7881-4D99-B6E2-623DC9A2E5D3/Documents/test.png
For getting Image in Image view:
UIImage *img = [UIImage imageWithContentsOfFile:yourPath];
//[UIImage imageWithData:[NSData dataWithContentsOfFile:yourPath]];
UIImageView *imgView = // Alloc + Init + Setting frame etc
imgView.image = img;
This will show image in your imageview
Hope this helps

filemanager in obj c

in my iPhone app I'm using file manager to check size of file,code is working fine on simulator, but when I run the same app on iphone it is saying file size is zero even though file size is greater than zero, I am using following code:
NSArray *paths1 = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory1 = [paths1 objectAtIndex:0];
documentsDirectory1 = [documentsDirectory1 stringByAppendingPathComponent:#"XML"];
NSString * szDestPath1 = [documentsDirectory1 stringByAppendingPathComponent:#"Extras"];
NSString *URL2 = [szDestPath1 stringByAppendingPathComponent:#"config.xml"];
NSLog(#"%#",URL2);
NSError *attributesError = nil;
NSDictionary *fileAttributes = [[NSFileManager defaultManager] attributesOfItemAtPath:URL2 error:&attributesError];
int _fileSize = [fileAttributes fileSize];
NSLog(#"_fileSize:%U",_fileSize); //0 if empty
How can I solve this, can anyone help me? thanx in advance.
Are you sure that the file exists?
Usually if a piece of code that involves files works fine on the simulator but not on the device it is because of wrong filenames. Most simulators run on a case-insensitive filesystem, but the device has a case-sensitive filesystem.
So please check again if you use the correct file path.
You could add something like this to make sure that the file exists:
if (![[NSFileManager defaultManager] fileExistsAtPath:URL2]) {
NSLog(#"File does not exist");
}

iPhone: Can access files in documents directory in Simulator, but not device

I'm writing an app that copies some contents of the bundle into the applications Document's directory, mainly images and media. I then access this media throughout the app from the Document's directory.
This works totally fine in the Simulator, but not on the device. The assets just come up as null. I've done NSLog's and the paths to the files look correct, and I've confirmed that the files exist in the directory by dumping a file listing in the console.
Any ideas? Thank you!
EDIT
Here's the code that copies to the Document's directory
NSString *pathToPublicationDirectory = [NSString stringWithFormat:#"install/%d",[[[manifest objectAtIndex:i] valueForKey:#"publicationID"] intValue]];
NSString *manifestPath = [[NSBundle mainBundle] pathForResource:#"content" ofType:#"xml" inDirectory:pathToPublicationDirectory];
[self parsePublicationAt:manifestPath];
// Get actual bundle path to publication folder
NSString *bundlePath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:pathToPublicationDirectory];
// Then build the destination path
NSString *destinationPath = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:#"%d", [[[manifest objectAtIndex:i] valueForKey:#"publicationID"] intValue]]];
NSError *error = nil;
// If it already exists in the documents directory, delete it
if ([fileManager fileExistsAtPath:destinationPath]) {
[fileManager removeItemAtPath:destinationPath error:&error];
}
// Copy publication folder to documents directory
[fileManager copyItemAtPath:bundlePath toPath:destinationPath error:&error];
I am figuring out the path to the docs directory with this method:
- (NSString *)applicationDocumentsDirectory {
return [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
}
And here's an example of how I'm building a path to an image
path = [NSString stringWithFormat:#"%#/%d/%#", [self applicationDocumentsDirectory], [[thisItem valueForKey:#"publicationID"] intValue], [thisItem valueForKey:#"coverImage"]];
It turned out to be an issue where the bundle was not being updated on the device and apparently didn't have the same set of files that the Simulator had. This blog post helped a bit: http://majicjungle.com/blog/?p=123
Basically, I cleaned the build and delete the app and installed directly to the device first instead of the simulator. Interesting stuff.
I don't see where documentsDirectory is defined.
NSString *destinationPath = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:#"%d", [[[manifest objectAtIndex:i] valueForKey:#"publicationID"] intValue]]];
Perhaps the following will do the trick
NSString *destinationPath = [[self applicationDocumentsDirectory] stringByAppendingPathComponent:[NSString stringWithFormat:#"%d", [[[manifest objectAtIndex:i] valueForKey:#"publicationID"] intValue]]];
Your copy code looks fine, and you say you're getting no errors.
But I'm intrigued by "The assets just come up as null." Are you sure you're accessing the file name later with the exact same name?
Unlike the simulator, a real iPhone has a case sensitive file system.