How to pick the Path Asset in a existing image with ALAssetsLibrary? - objective-c

Question

I have this code who write / Create a new image in iOS photo library:
ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
// Request to save the image to camera roll
[library writeImageToSavedPhotosAlbum:[imagem CGImage] orientation:(ALAssetOrientation)[imagem imageOrientation] completionBlock:^(NSURL *assetURL, NSError *error){
//code here...
}
The code that does this, is probably stamped in code writeImageToSavedPhotosAlbum, but in this time I don`t need to create a new image in library, I need to get the Path of the image who exist in the library, In my case the image is inside the variable 'imagem'.
What code I could change the writeImageToSavedPhotosAlbum to get the Path of image?
[EDIT]
I get the image inside the variable imagem in this format:
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{
UIImage *imagem = [info objectForKey:UIImagePickerControllerOriginalImage];
[imagePicker dismissViewControllerAnimated:YES completion:nil];
}

Answer 1

You have:
-(void)imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)info{
UIImage *imagem = [info objectForKey: UIImagePickerControllerOriginalImage];
}
But you say you don't need the image; you just need the path. That would be:
-(void)imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary *)info{
NSURL *imageurl = [info objectForKey: UIImagePickerControllerReferenceURL];
}
Now you have the URL and you can store it; you can then retrieve the actual image later if you need it.
To get from an asset URL to an image, see my answer here: https://stackoverflow.com/a/22968941/341994

Answer 2

Use ALAssetRepresentation...
[library enumerateGroupsWithTypes:ALAssetsGroupSavedPhotos usingBlock:^(ALAssetsGroup *group, BOOL *stop) {
// Within the group enumeration block, filter to enumerate just photos.
[group setAssetsFilter:[ALAssetsFilter allPhotos]];
// Chooses the photo at the last index
[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];
UIImage *latestPhoto = [UIImage imageWithCGImage:[representation fullScreenImage]];
Or if you want the path...
NSURL *imageUrl = [representation url];