Saving in NSDocumentDirectory - iphone

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

Related

Iphone-saving full size image to document directory hangs my app

I am working on an app similar to photo app in iPhone. The flow is I get images through UIImagePickerController. When I use Actual image and further save that image to documents,
My app hangs. I saw on profile tool that allocation goes to 19 to 20 mb. If there is any solution to that.
Getting image from UIImagepicker controller
Saving it to documents.
-(NSString *)saveImageInDocumentsAtPath:(NSNumber *)number
{
NSString *fileName=[NSString stringWithFormat:#"image%#.png",number];
NSString *imagePath= [[NSString alloc] initWithFormat:#"%#/%#", [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0],fileName];
UIImage *image = self.selectedImage.image;
NSData *imageData = UIImagePNGRepresentation(image);
[imageData writeToFile:imagePath atomically:YES];
return imagePath;
}
A typical image is going to be around 3Megabytes, if I am not mistaken (depending on the iPhone and its camera). So going from 19 to 20 is not unreasonable. Why you are at 19 to begin with ay be another question. See if you're loading in too many other images, large files etc.
If you use AV Foundation instead of ImagePicker, you have some other options for handling the images.
And you can write the image to the filesystem asynchronously.
This looks like a great opportunity for some error checking in your code.
Why not try this?
-(NSString *)saveImageInDocumentsAtPath:(NSNumber *)number
{
NSString *fileName=[NSString stringWithFormat:#"image%#.png",number];
NSArray * docDirectoryArray = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
if(docDirectoryArray)
{
NSString *imagePath= [[NSString alloc] initWithFormat:#"%#/%#", [docDirectoryArray objectAtIndex:0],fileName];
UIImage *image = self.selectedImage.image;
if(image)
{
NSData *imageData = UIImagePNGRepresentation(image);
if(imageData)
{
BOOL success = [imageData writeToFile:imagePath atomically:YES];
if(success)
{
// only return the image path in the success == YES case
return imagePath;
} else {
NSLog( #"did not save file to %#", imagePath);
}
} else {
NSLog( #"could not get image data out of the image");
}
} else {
NSLog( #"no image selected");
}
}
// you might want to check in the caller to make certain the imagePath is NULL
return NULL;
}

Storing and retrieving images on iPhone efficiently

I have an application which donwloads several images and stores them on the phone. In total it will probably required around 20 images tops. I need to be able to retrieve any of these images at will depending on what screen the user is on. These images will be stored indefinitely, so I don't want to use temp directory.
At present I have a class named Images with these methods
- (void) cacheImage: (NSString *) ImageURLString : (NSString *)imageName
{
NSURL *ImageURL = [NSURL URLWithString: ImageURLString];
// Generate a unique path to a resource representing the image you want
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docDir = [paths objectAtIndex: 0];
NSString *docFile = [docDir stringByAppendingPathComponent: imageName];
// Check for file existence
if(![[NSFileManager defaultManager] fileExistsAtPath: docFile])
{
// The file doesn't exist, we should get a copy of it
// Fetch image
NSData *data = [[NSData alloc] initWithContentsOfURL: ImageURL];
UIImage *image = [[UIImage alloc] initWithData: data];
// Is it PNG or JPG/JPEG?
// Running the image representation function writes the data from the image to a file
if([ImageURLString rangeOfString: #".png" options: NSCaseInsensitiveSearch].location != NSNotFound)
{
[UIImagePNGRepresentation(image) writeToFile: docFile atomically: YES];
}
else if([ImageURLString rangeOfString: #".jpg" options: NSCaseInsensitiveSearch].location != NSNotFound ||
[ImageURLString rangeOfString: #".jpeg" options: NSCaseInsensitiveSearch].location != NSNotFound)
{
[UIImageJPEGRepresentation(image, 100) writeToFile: docFile atomically: YES];
}
}
}
- (UIImage *) getCachedImage : (NSString *)imageName
{
NSArray *paths = NSSearchPathForDirectoriesInDomains
(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString* cachedPath = [documentsDirectory stringByAppendingPathComponent:imageName];
UIImage *image;
// Check for a cached version
if([[NSFileManager defaultManager] fileExistsAtPath: cachedPath])
{
image = [UIImage imageWithContentsOfFile: cachedPath]; // this is the cached image
}
else
{
NSLog(#"Error getting image %#", imageName);
}
return image;
}
-(void)getImages
{
//example
NSString *image1URL = #"http://test/image1.png";
NSString *image2URL = #"http://test/image2.png";
NSString *image3URL = #"http://test/image3.png";
[self cacheImage:sLogo: #"Image1"];
[self cacheImage:sBlankNav: #"Image2"];
[self cacheImage:buttonLarge :#"Image3"];
}
-(void) storeImages
{
image1 = [self getCachedImage:#"Image1"];
image2 = [self getCachedImage:#"Image2"];
image3 = [self getCachedImage:#"Image3"];
}
So I use the code like this
Images *cache = [[Images alloc]init];
[cache storeImages];
The get images method is called once when the app first starts to get the images, it isn't called again after that, unless the images on the server are updated and I need to retrieve the updated ones.
The code works, but the problem is when I navigate to a screen that uses it, there is a very slight delay before the screen loads as it is loading the images.
My application is a tabbed application, so it begins on tab 1, I click tab 2 which implements the code, there will be a slight pause the first time it loads. It doesn't last very long, but it is noticeable and is very annoying. After that it is fine, as it is already loaded. However with navigation controller, every time you move from the first VC to the second VC, the method will be called again, so each time you navigate the delay will be there.
The images are not very big, biggest one is 68kb, others are much smaller than that. At present I am just testing with 5 images. Is there a more efficient way of storing and retrieving images, or am I doing something wrong with my code? I need to be able to retrieve these images without any noticeable delay in order for my application to remain fluid and not jerky or clunky.
Thanks in advance!!
You have two options to do the image loading work on a background thread - use Grand Central Dispatch or NSInvocationOperation. GCD might be considered the cleaner of the two:
dispatch_queue_t q = dispatch_get_global_queue(0, 0);
dispatch_queue_t main = dispatch_get_main_queue();
dispatch_async(q, ^{
//load images here
dispatch_async(main, ^{
// show on main thread here
});
});
you have delay because you're downloading data synchronously
// NSData *data = [[NSData alloc] initWithContentsOfURL: ImageURL];
Try some smart library like SDWebImage:
it lets you download image asynchronously while you still can display a local image (a proxy image). By the way, you still get cache image for free. So even if u are on local, you can still catch previously downloaded images
https://github.com/rs/SDWebImage
A must have

Corrupted Images in document directory

I am fetching URL of the images from the server and converting this images into png format using:
NSData *data1 = [NSData dataWithData:UIImagePNGRepresentation(img)];
[data1 writeToFile:pngFilePath atomically:YES];
but some of the images are corrupted when i check them after completing the process on simulator.
Hence these images are not displaying on the app wherever needed.
Please see the attached image as some images are corrupted.
Update
I am calling a method in a loop which fetches the images from the server parallel and didFinishLoading I am performing this:
UIImage *img = [UIImage imageWithData:self.data];
NSArray *split = [self.strImageName componentsSeparatedByString:#"/"];
int arrCount=[split count];
NSString *imageName=[split objectAtIndex:arrCount-1];
NSString *docDirec = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *pngFilePath=nil
pngFilePath = [NSString stringWithFormat:#"%#/Thumbs/%#",docDirec,imageName];
NSData *data1 = [NSData dataWithData:UIImagePNGRepresentation(img)];
[data1 writeToFile:pngFilePath atomically:YES];
[self.data release]; //don't need this any more, its in the UIImageView now
self.data=nil;
i have the similar problem
i solved it using the below code
- (void)viewWillDisappear:(BOOL)animated
{
if (self.m_objWebManager != nil)//Webmanager is class for downloading the images as a background thread
{
[self.m_objWebManager cancelCommunication];
[self.m_objWebManager release];
self.m_objWebManager = nil;
}
}

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

Why might this code be giving me null?

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