I need to know if an image is already in the iOS gallery. I am developing a messaging client app and, in my chat list, I am able to download images/videos of incoming messages when I tap into the image thumbnail.
The issue is, when I tap in the thumbnail, I download and save that image into the iOS photo gallery, but if I tap again I don't want to download and save it again, I want to retrieve it from the photo gallery.
Resuming, I want to look for the image in the photo gallery and retrieve it.
Here is my code to save the image in my custom photo album using ALAssetsLibrary:
[self writeImageToSavedPhotosAlbum:image.CGImage orientation:(ALAssetOrientation)image.imageOrientation completionBlock:
^(NSURL* assetURL, NSError* error)
{
if (error!=nil) {
completionBlock(error);
return;
}
//add the asset to the custom photo album
[self addAssetURL: assetURL
toAlbum:albumName
withCompletionBlock:completionBlock];
}
];
-(void)addAssetURL:(NSURL*)assetURL toAlbum:(NSString*)albumName withCompletionBlock:(SaveImageCompletion)completionBlock
{
__block BOOL albumWasFound = NO;
[self enumerateGroupsWithTypes:ALAssetsGroupAlbum
usingBlock:
^(ALAssetsGroup *group, BOOL *stop)
{
if ([albumName compare: [group valueForProperty:ALAssetsGroupPropertyName]]==NSOrderedSame) {
albumWasFound = YES;
[self assetForURL: assetURL
resultBlock:
^(ALAsset *asset)
{
//add photo to the target album
[group addAsset: asset];
completionBlock(nil);
} failureBlock: completionBlock
];
return;
}
if (group==nil && albumWasFound==NO) {
//Target album does not exist, create it
__weak ALAssetsLibrary* weakSelf = self;
[self addAssetsGroupAlbumWithName:albumName
resultBlock:
^(ALAssetsGroup *group)
{
[weakSelf assetForURL: assetURL
resultBlock:
^(ALAsset *asset)
{
//add photo to the newly created album
[group addAsset: asset];
completionBlock(nil);
} failureBlock: completionBlock
];
} failureBlock: completionBlock
];
return;
}
} failureBlock: completionBlock
];
}
Maybe with the assetURL I could do it, but I have been searching in Apple's documentation and I didn't see anything.
Thanks!!
You can get Asset URL after the save process using completion block. You can retrieve the saved image using this Asset URL.
Unfortunately, you can't check file exist in Photolibrary. The reason behind is, the system will automatically embed many extra information with the image while you save in to Photolibrary. example like location, time etc.. So the binary content will be different for same images.
So, you have only one solution. Save the images into document directory and do a file exist using algorithms like CRC, MD5 etc..
Related
I am iOS developer i want to get all images from library, without UIImagepickercontroller,and take first 10 images
Any ideas?
There are lots of example out der which will guide you how to get images from ALAssetLibrary
https://www.cocoacontrols.com/search?q=image+picker.
Below is example to get the latest image from ImagePicker
- (void)latestPhotoWithCompletion:(void (^)(UIImage *photo))completion
{
ALAssetsLibrary *library=[[ALAssetsLibrary alloc] init];
// Enumerate just the photos and videos group by using ALAssetsGroupSavedPhotos.
[library enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
// Within the group enumeration block, filter to enumerate just photos.
[group setAssetsFilter:[ALAssetsFilter allPhotos]];
// For this example, we're only interested in the last item [group numberOfAssets]-1 = last.
if ([group numberOfAssets] > 0) {
[group enumerateAssetsAtIndexes:[NSIndexSet indexSetWithIndex:[group numberOfAssets]-1] options:0
usingBlock:^(ALAsset *alAsset, NSUInteger index, BOOL *innerStop) {
// The end of the enumeration is signaled by asset == nil.
if (alAsset) {
ALAssetRepresentation *representation = [alAsset defaultRepresentation];
// Do something interesting with the AV asset.
UIImage *img = [UIImage imageWithCGImage:[representation fullScreenImage]];
// completion
completion(img);
// we only need the first (most recent) photo -- stop the enumeration
*innerStop = YES;
}
}];
}
} failureBlock: ^(NSError *error) {
// Typically you should handle an error more gracefully than this.
}];
}
Usage
__weak __typeof(self)wSelf = self;
[self latestPhotoWithCompletion:^(UIImage *photo) {
UIImageRenderingMode renderingMode = YES ? UIImageRenderingModeAlwaysOriginal : UIImageRenderingModeAlwaysTemplate;
[wSelf.switchCameraBut setImage:[photo imageWithRenderingMode:renderingMode] forState:UIControlStateNormal];
}];
I am creating an app that fetches photos and videos from the library.
I am using ALAssetsLibrary to fetch the contents from the library. But I can't retrieve the videos album from the library using this.
I am using the following code to retrieve the contents:
[library enumerateGroupsWithTypes:ALAssetsGroupAll usingBlock:^(ALAssetsGroup *group, BOOL *stop)
{
if (group || group.numberOfAssets >= 1)
{
[tmpAssets addObject:group];
}else{
self.assetAlbums = tmpAssets;
*stop = YES;
if(self.assetAlbums.count){
//parse contents and reload view
}
}
}
failureBlock:^(NSError *error)
{
//failed
}];
I am getting all other pictures and videos.
I have used a workaround of creating one videos album and filling its contents with the results from the ALAssetsLibraryGroupsEnumerationResultsBlock with allVideos filter.
but the ones that I upload from iTunes (those that get into the videos folder in the library) are not getting retrieved.
I want to create custom photo album and save photo to specific album in iOS 7. and I found iOS save photo in an app specific album using ALAssetsLibrary.
But I don't know how to do it using UIActivityViewController.
NSArray* actItems = [NSArray arrayWithObjects: image, nil];
UIActivityViewController *activityView = [[UIActivityViewController alloc]
initWithActivityItems:actItems
applicationActivities:nil];
[activityView setCompletionHandler:^(NSString *activityType, BOOL completed)
{
if ([activityType isEqualToString:UIActivityTypeSaveToCameraRoll])
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:NSLocalizedString(#"#Saved_title", nil)
message:NSLocalizedString(#"#Saved_message2", nil)
delegate:self
cancelButtonTitle:NSLocalizedString(#"OK", nil)
otherButtonTitles: nil];
[alert show];
}
}];
I realize the question is a few months old and that the OP may have moved on, but I needed to do exactly this, but didn't find another solution, and needed to come up with my own.
It's not fool-proof, as if there are multiple copies of the video/image in Camera Roll that you're wanting to copy, it will copy all of them, which may or may not be desired. Also, for my purposes, I'm considering maintaining a persistent list of asset URLs that I've written to the custom album so that I skip that asset in the future, but I haven't yet coded it because, if the user removes the video/image from the custom album, it'd be nearly impossible to update that list without more iteration through asset groups: something I'd like to avoid.
Last disclaimer: I haven't tested this a whole ton yet, but it works for my purposes, so hopefully someone else out there can benefit from it.
I augmented Marin Todorov's ALAssetsLibrary+CustomPhotoAlbum category, which I found here: https://github.com/yusenhan/Smooth-Line-View/tree/master/ALAssetsLibrary%2BCustomPhotoAlbum. Note: there is no license information provided there, so I'm assuming that modifying the source for this category is ok.
Here is my method which sets up and displays the UIActivityViewController:
- (void)showActivitySheet:(NSString *)path {
NSURL *newURL = [NSURL fileURLWithPath:path];
NSArray *itemsToShare = #[newURL];
UIActivityViewController *activityVC = [[UIActivityViewController alloc] initWithActivityItems:itemsToShare applicationActivities:nil];
activityVC.excludedActivityTypes = #[UIActivityTypePrint, UIActivityTypeAssignToContact, UIActivityTypeAddToReadingList];
// Once the OS has finished with whatever the user wants to do with it,
// we'll begin figuring out if we need to save it to the Album, too!
[activityVC setCompletionHandler:^(NSString *activityType, BOOL completed) {
// If the user selected "Save to Camera Roll"
if ([activityType isEqualToString:UIActivityTypeSaveToCameraRoll]) {
ALAssetsLibrary *lib = [[ALAssetsLibrary alloc] init];
NSURL *tempUrl = [NSURL fileURLWithPath:path];
// saveMovie: below is a method I added to the category, but you can use saveImage:,
// which you'll also likely want to add some kind of parameter to so, in the category,
// you know when you only want to copy to the Album instead of the Album AND Camera Roll
[lib saveMovie:tempUrl toAlbum:#"CUSTOM ALBUM NAME"
withCompletionBlock:^(NSURL *url, NSError *error) {
if (error) {
NSLog(#"Error writing movie to custom album: %#", error.debugDescription);
}
}
onlyWriteToCustomAlbum:YES];
}
}];
[self presentViewController:activityVC animated:YES completion:nil];
}
Here is code you can add to the saveImage: method in the ALAssetsLibrary+CustomPhotoAlbum category so you can save it to your custom Album, too! You could execute this portion only on the YES case of the BOOL which you'll want to add to the category.
NSData *dataToCompareTo = [NSData dataWithContentsOfURL:url]; // This data represents the image/movie which you want to save into the custom album. The one you handed to the UIActivityViewController.
// Note use of self, as this is a category on ALAssetsLibrary; also, this
// assumes that you've already written the photo to the Camera Roll, which
// should be automatically handled by the OS, if the user hit the "Save" button
// on the UIActivityViewController.
// Enumerate through Camera Roll/Saved Photos group.
[self enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos
usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
// Enumerate the assets in each group.
[group enumerateAssetsUsingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop) {
ALAssetRepresentation *rep = [result defaultRepresentation];
// If the asset isn't the same size as the source image/movie
// it shouldn't be the same. Check the size first, since it
// is a less costly operation than byte checking the data itself.
if ([rep size] == [dataToCompareTo length]) {
Byte *buffer = malloc([NSNumber numberWithLongLong:rep.size].unsignedLongValue);
NSUInteger buffered = [rep getBytes:buffer fromOffset:0.0 length:[NSNumber numberWithLongLong:rep.size].unsignedLongValue error:nil];
NSData *data = [NSData dataWithBytesNoCopy:buffer length:buffered freeWhenDone:YES];
// If the buffer has more than the null-termination char, free it! I'm doing this in case the above call to dataWithBytesNoCopy fails to free() the buffer.
if (sizeof(buffer) > 4) {
free(buffer);
}
// Ensure they are the same by comparing the NSData instances.
if ([data isEqualToData:dataToCompareTo]) {
NSLog(#"they are the same!!");
[self addAssetURL:[rep url]
toAlbum:albumName
withMovieCompletionBlock:completionBlock];
} else {
NSLog(#"they are different");
}
}
}];
} failureBlock:^(NSError *error) {
NSLog(#"Failed to write to custom album!");
}];
Hope it helps! TLDR? Thought so! ;-)
How can I save the images to iPad's Gallery, and again read them from there into my App.
Is it possible to create a folder structure in iPad's gallery where I could store images generated through my app.
Actually I am able to save the images to gallery, I am using this
UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);
But don't know how to load it back into app from gallery. ?
Use the ALAssetsLibrary, then you can call writeImageToSavedPhotosAlbum:metadata:completionBlock: to save the image and in the completion block you get the assetURL. This can later be used to get the image back from the library.
Docs are here .
To get the image for the asset url:
[self.assetsLibrary assetForURL:imageURL resultBlock:^(ALAsset *asset) {
if (asset != nil) {
imageView.image = [UIImage imageWithCGImage:[[asset defaultRepresentation] fullScreenImage]];
}
} failureBlock:^(NSError * error) {
NSLog (#"Error getting image asset: %#", error);
}];
I am able to save an image into a custom album in the iPhone camera roll. For example, the album name could be "Fun", and all of the images I take will go into that folder. I came across a helper class here that works very well to accomplish what I want.
However, the method I am using does not save videos into the custom folder, but the folder is created - it's just empty of any videos that I attempt to save there. I tried debugging it with no progress. That method is here:
-(void)addAssetURL:(NSURL*)assetURL toAlbum:(NSString*)albumName withCompletionBlock:(SaveImageCompletion)completionBlock
{
__block BOOL albumWasFound = NO;
//search all photo albums in the library
[self enumerateGroupsWithTypes:ALAssetsGroupAlbum
usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
//compare the names of the albums
if ([albumName compare: [group valueForProperty:ALAssetsGroupPropertyName]]==NSOrderedSame) {
//target album is found
albumWasFound = YES;
NSData *data = [NSData dataWithContentsOfURL:assetURL];
if ([data length] > 0) {
//get a hold of the photo's asset instance
[self assetForURL: assetURL
resultBlock:^(ALAsset *asset) {
[group addAsset: asset];
//run the completion block
completionBlock(nil);
} failureBlock: completionBlock];
}
//album was found, bail out of the method
return;
}
if (group==nil && albumWasFound==NO) {
//photo albums are over, target album does not exist, thus create it
__weak ALAssetsLibrary* weakSelf = self;
//create new assets album
[self addAssetsGroupAlbumWithName:albumName
resultBlock:^(ALAssetsGroup *group) {
//get the photo's instance
[weakSelf assetForURL: assetURL
resultBlock:^(ALAsset *asset) {
NSLog(#"asset: %#",asset);
//add photo to the newly created album
[group addAsset: asset];
//call the completion block
completionBlock(nil);
} failureBlock: completionBlock];
} failureBlock: completionBlock];
//should be the last iteration anyway, but just in case
return;
}
} failureBlock: completionBlock];
}
Does anyone know the proper way to save a video into a custom album in the photo library?
Try this, it works for me.
-(void)saveVideo:(NSURL *)videoUrl toAlbum:(NSString*)albumName withCompletionBlock: (SaveImageCompletion)completionBlock
{
//write the image data to the assets library (camera roll)
[self writeVideoAtPathToSavedPhotosAlbum:videoUrl completionBlock:^(NSURL* assetURL, NSError* error) {
//error handling
if (error!=nil) {
completionBlock(error);
return;
}
//add the asset to the custom photo album
[self addAssetURL: assetURL
toAlbum:albumName
withCompletionBlock:completionBlock];
}];
}