Getting NSData from an NSURL - alassetslibrary

Question

I am trying to upload a photo from my app into a web service.
The flow I am attempting to create is as follows:
User takes photo with camera
Photo is saved to camera roll under a custom album
URL of the saved photo is given to my store
Store attempts to upload the photo to a web service.
I am trying to use NSData *data = [NSData dataWithContentsOfURL:[item assetURL]] where item is a model that contains the URL concerned. But this line is not producing a data when I log it even if it produces a URL: "assets-library://asset/asset.PNG?id=28DBC0AC-21FF-4560-A9D6-5F4BCA190BDB&ext=PNG"
The code snippets are as follows:
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
[self dismissViewControllerAnimated:YES completion:^(void){
[library writeImageToSavedPhotosAlbum:image.CGImage orientation:image.imageOrientation completionBlock:^(NSURL* assetURL, NSError* error) {
BCard *card = [[BCard alloc]init];
//error handling
if (error!=nil) {
NSLog(#"[ERROR] - %#",error);
return;
}
//add the asset to the custom photo album
[library addAssetURL: assetURL
toAlbum:#"Business Cards"
withCompletionBlock:^(NSError *error) {
if (error!=nil) {
NSLog(#"Custom Album Error: %#", [error description]);
}
}];
[card setAssetURL:assetURL];
[[BCardStore sharedStore]addToQueue:card];
int index = [[[BCardStore sharedStore]getQueue]count]-1;
[[BCardStore sharedStore]uploadItemAtIndex:index withProgressBlock:nil withExitBlock:nil];
}];
}];
}
and
-(void)uploadItemAtIndex:(NSUInteger)index withProgressBlock:(progressBlock)pBlock withExitBlock:(exitBlock)eBlock
{
BCard *item = [uploadQueue objectAtIndex:index];
NSURL *url = [NSURL URLWithString:#"http://192.168.0.116:8080"];
NSData *data = [NSData dataWithContentsOfURL:[item assetURL]];
AFHTTPClient *httpClient = [[AFHTTPClient alloc]initWithBaseURL:url];
numberedName = numberedName +1;
NSString *name = [NSString stringWithFormat:#"%d",numberedName];
NSLog(#"%#",[item assetURL]);
//upload data using AFNetworking here
}
The snippet [library addAssetUrl:NSUrl toAlbum:NSString withCompletionBlock:^(NSError *error)] came from the category I found here.
Am I really getting the right URL here or am I using dataWithContentsOfURL incorrectly?

Answer 1

The only way is You can retrieve the UIImage from Photo-Library using ALAsset URL and convert in to NSData.
Add ALAssetLibrary
Import ALAssetLibrary header file
-(void)uploadItemAtIndex:(NSUInteger)index
withProgressBlock:(progressBlock)pBlock
withExitBlock:(exitBlock)eBlock
{
ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset *myasset)
{
ALAssetRepresentation *rep;
if([myasset defaultRepresentation] == nil) {
return;
} else {
rep = [myasset defaultRepresentation];
}
CGImageRef iref = [rep fullResolutionImage];
dispatch_sync(dispatch_get_main_queue(), ^{
UIImage *myImage = [UIImage imageWithCGImage:iref];
NSData *data = //convert the myImage to NSData
BCard *item = [uploadQueue objectAtIndex:index];
NSURL *url = [NSURL URLWithString:#"http://192.168.0.116:8080"];
AFHTTPClient *httpClient = [[AFHTTPClient alloc]initWithBaseURL:url];
numberedName = numberedName +1;
NSString *name = [NSString stringWithFormat:#"%d",numberedName];
//upload data using AFNetworking here
});//end block
};
ALAssetsLibraryAccessFailureBlock failureblock = ^(NSError *myerror)
{
NSLog(#"Cant get image - %#",[myerror localizedDescription]);
};
NSURL *asseturl =
[NSURL URLWithString:[self.photoPath objectAtIndex:[arrayIndex intValue] ]];
//using ARC , you have to declare ALAssetsLibrary as member variable
ALAssetsLibrary* assetslibrary = [[ALAssetsLibrary alloc] init];
[assetslibrary assetForURL:assetURL
resultBlock:resultblock
failureBlock:failureblock];
}