Accessing Videos in library using AssetsLibrary framework iPhone? - ios

Question

I am trying to access videos in iPhone library using AssetsLibrary Framework with the help of following code...but when I run the application the code is not working...the array assets is still empty? What am I doing wrong?
by the way my iPhone is a 3G upgraded to iPhone 4.1.(but assets framework is not giving any error)
NSMutableArray *assets = [[NSMutableArray alloc]init];
ALAssetsLibrary *library = [[ALAssetsLibrary alloc]init];
void (^assetEnumerator)(struct ALAsset *, NSUInteger, BOOL *) = ^(ALAsset *result, NSUInteger index, BOOL *stop) {
if(result != NULL) {
NSLog(#"See Asset: %#", result);
[assets addObject:result];
}
};
void (^assetGroupEnumerator)(struct ALAssetsGroup *, BOOL *) = ^(ALAssetsGroup *group, BOOL *stop) {
if(group != nil) {NSLog(#"dont See Asset: ");
[group enumerateAssetsUsingBlock:assetEnumerator];
}
};
assets = [[NSMutableArray alloc] init];
library = [[ALAssetsLibrary alloc] init];
[library enumerateGroupsWithTypes:ALAssetsGroupAlbum
usingBlock:assetGroupEnumerator
failureBlock: ^(NSError *error) {
NSLog(#"Failure");
}];

Answer 1

the 4.1 upgrade seems to have 'broken' some of the image picker examples, observe the following lines, which run after the code you have posted:
NSUInteger groupTypes = ALAssetsGroupAlbum | ALAssetsGroupEvent | ALAssetsGroupFaces;
[assetsLibrary enumerateGroupsWithTypes:groupTypes usingBlock:listGroupBlock failureBlock:failureBlock];
This gives zero assets both on my 4.1 iPhone and simulator. However changing the groupTypes helps, so set
NSUInteger groupTypes = ALAssetsGroupAll;
and you should start seeing some assets.

Answer 2

I did this in Xcode 4.1, IOS 5:
ALAssetsGroupEnumerationResultsBlock assetEnumerator = ^(ALAsset *result, NSUInteger index, BOOL *stop) {
if(result != NULL) {
NSLog(#"See Asset: %#", result);
[assets addObject:result];
}
};
ALAssetsLibraryGroupsEnumerationResultsBlock assetGroupEnumerator = ^(ALAssetsGroup *group, BOOL *stop) {
if(group != nil) {NSLog(#"dont See Asset: ");
[group enumerateAssetsUsingBlock:assetEnumerator];
}
};
assets = [[NSMutableArray alloc] init];
library = [[ALAssetsLibrary alloc] init];
[library enumerateGroupsWithTypes:ALAssetsGroupAlbum
usingBlock:assetGroupEnumerator
failureBlock: ^(NSError *error) {
NSLog(#"Failure");
}];
It worked for me.

Answer 3

Double Init:
NSMutableArray *assets = [[NSMutableArray alloc]init];
ALAssetsLibrary *library =[[ALAssetsLibrary alloc]init];
void (^assetEnumerator)(struct ALAsset *, NSUInteger, BOOL *) = ^(ALAsset *result, NSUInteger index, BOOL *stop) {
if(result != NULL) {
NSLog(#"See Asset: %#", result);
[assets addObject:result];
}
};
void (^assetGroupEnumerator)(struct ALAssetsGroup *, BOOL *) = ^(ALAssetsGroup *group, BOOL *stop) {
if(group != nil) {NSLog(#"dont See Asset: ");
[group enumerateAssetsUsingBlock:assetEnumerator];
}
};
assets = [[NSMutableArray alloc] init];
library = [[ALAssetsLibrary alloc] init**];
[library enumerateGroupsWithTypes:ALAssetsGroupAlbum
usingBlock:assetGroupEnumerator
failureBlock: ^(NSError *error) {
NSLog(#"Failure");
}];

Answer 4

I am using ELC Image Picker Controller, and it's already using ALAssetsGroupAll and still not showing any videos.
I solved this by adding an asset filter. You can limit to videos, photos or both. I guess photos-only was the default. Please consider the following line if the above fails:
[assetGroup setAssetsFilter:[ALAssetsFilter allAssets]];