Always save screenshot in same custom name app album in "Photos" - ios

Question

I am building an app with button that make screen shot. Now I want to save all screen shots made in this app, in same custom name app album. I already know how to create album just the first time that app opens with code bellow.
I am creating my album with Photos framework like:
-(void)createAppAlbum
{
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
PHAssetCollectionChangeRequest *changeRequest = [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:#"App Album Name"];
albumPlaceholder = changeRequest.placeholderForCreatedAssetCollection;
}
completionHandler:^(BOOL success, NSError *error) {
if (success) {
fetchResult = [PHAssetCollection fetchAssetCollectionsWithLocalIdentifiers:#[albumPlaceholder.localIdentifier] options:nil];
assetCollection = fetchResult.firstObject;
}
else {
NSLog(#"Error creating album: %#", error);}
}];
}
So my app creates album named "App Album Name".
I am able to take and store my screenshot in my new album with button like:
-(IBAction)screenshot:(id)sender
{
if ([[UIScreen mainScreen] respondsToSelector:#selector(scale)])
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, NO, [UIScreen mainScreen].scale);
else
UIGraphicsBeginImageContext(self.view.bounds.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
PHAssetChangeRequest *assetChangeRequest = [PHAssetChangeRequest creationRequestForAssetFromImage:image];
PHAssetCollectionChangeRequest *assetCollectionChangeRequest = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:assetCollection];
[assetCollectionChangeRequest addAssets:#[[assetChangeRequest placeholderForCreatedAsset]]];
} completionHandler:^(BOOL success, NSError *error) {
if (!success) {
NSLog(#"Error creating asset: %#", error);
}
}];
}
In case I leave this viewController, and get back in later, I want to find album that I already created, and save another screen shot in same album, because I don't want to create new one every time I enter this view controller.
So my question is, how would I get album I created first time by Name and then save new screen shots in.

Answer 1

Since this question is specifically targeting, iOS 8, this code will work just fine:
- (void)saveImage:(UIImage *)image {
if (!self.library) {
self.library = [[ALAssetsLibrary alloc] init];
}
__weak ALAssetsLibrary *lib = self.library;
[self.library addAssetsGroupAlbumWithName:#"My Photo Album" resultBlock:^(ALAssetsGroup *group) {
///checks if group previously created
if(group == nil){
//enumerate albums
[lib enumerateGroupsWithTypes:ALAssetsGroupAlbum
usingBlock:^(ALAssetsGroup *g, BOOL *stop)
{
//if the album is equal to our album
if ([[g valueForProperty:ALAssetsGroupPropertyName] isEqualToString:#"My Photo Album"]) {
//save image
[lib writeImageDataToSavedPhotosAlbum:UIImagePNGRepresentation(image) metadata:nil
completionBlock:^(NSURL *assetURL, NSError *error) {
//then get the image asseturl
[lib assetForURL:assetURL
resultBlock:^(ALAsset *asset) {
//put it into our album
[g addAsset:asset];
} failureBlock:^(NSError *error) {
}];
}];
}
}failureBlock:^(NSError *error){
}];
}else{
// save image directly to library
[lib writeImageDataToSavedPhotosAlbum:UIImagePNGRepresentation(image) metadata:nil
completionBlock:^(NSURL *assetURL, NSError *error) {
[lib assetForURL:assetURL
resultBlock:^(ALAsset *asset) {
[group addAsset:asset];
} failureBlock:^(NSError *error) {
}];
}];
}
} failureBlock:^(NSError *error) {
}];
}
To test that this works, I created a single screen application, added a button to the view, and added a method that takes a screenshot and then passes the image to the saveImage: function. Here's the code that I added to it to make it work:
#import <AssetsLibrary/AssetsLibrary.h>
#interface ViewController ()
#property (nonatomic, strong) UIButton *screenshotButton;
#property (nonatomic, strong) ALAssetsLibrary *library;
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[self.view addSubview:self.screenshotButton];
}
- (UIButton *)screenshotButton {
if (!_screenshotButton) {
_screenshotButton = [[UIButton alloc] initWithFrame:CGRectInset(self.view.bounds, 100.0f, 120.0f)];
_screenshotButton.layer.borderColor = [UIColor blueColor].CGColor;
_screenshotButton.layer.borderWidth = 2.0f;
_screenshotButton.layer.cornerRadius = 5.0f;
[_screenshotButton setTitle:#"Take Screenshot" forState:UIControlStateNormal];
[_screenshotButton setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];
[_screenshotButton addTarget:self action:#selector(takeScreenshot) forControlEvents:UIControlEventTouchUpInside];
}
return _screenshotButton;
}
- (void)takeScreenshot {
if ([[UIScreen mainScreen] respondsToSelector:#selector(scale)])
UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, NO, [UIScreen mainScreen].scale);
else
UIGraphicsBeginImageContext(self.view.bounds.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
NSData * imgData = UIImagePNGRepresentation(image);
if(imgData)
[imgData writeToFile:#"screenshot.png" atomically:YES];
else
NSLog(#"error while taking screenshot");
UIColor *randomColor = [UIColor colorWithHue:((CGFloat)(arc4random()%255)/255.0f)
saturation:((CGFloat)(arc4random()%255)/200.0f)
brightness:((CGFloat)(arc4random()%100)/255.0f) + 0.5f
alpha:1.0f];
self.screenshotButton.layer.borderColor = randomColor.CGColor;
[self.screenshotButton setTitleColor:randomColor forState:UIControlStateNormal];
[self saveImage:image];
}
A few things to note:
AssetsLibrary is deprecated in iOS 9, so it is not recommended to
be used after iOS 8, but will still work.
This can be implemented and
used with any UIImage passed to saveImage:, so it can work even
if you're using another library.
Make sure to include #import <AssetsLibrary/AssetsLibrary.h>.
Change "My Photo Album" to the correct album name, and possibly set that statically