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Possible Duplicate:
How can i avoid Location service in AlAssetLibrary? Can i retrieve files using AlAssetLibrary without using Location Service?

Hi all, I am a newbie in iphone development and obj-c. i am using "ALAssetLibrary" in my Application to retrieve images from Photo Library. I identified that "ALAssetPropertyLocation"Property Key only available if location services are enabled for the caller. it is the key to retrieve the location information of the asset.But i am not using "ALAssetPropertyLocation"Property.i am using only ALAssetPropertyURLs.

whenever i am trying to deploy my Application in a new device there is a message box with the message "Location Service needed.." can i able to hide the "ALAssetPropertyLocation"Property?

I would really appreciate if someone could assist me in the correct way to approach my problem, and if possible any sample code to get my started.

Thank You In Advance :)

this is my Code:

//Getting image url from dictionary according to the user input
NSURL *imageurl = [dict objectForKey: [youSaid text]];   

//Getting asset from url
typedef void (^ALAssetsLibraryAssetForURLResultBlock)(ALAsset *asset);
typedef void (^ALAssetsLibraryAccessFailureBlock)(NSError *error);    
ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset *myasset)
{
    ALAssetRepresentation *rep = [myasset defaultRepresentation];
    CGImageRef iref = [rep fullResolutionImage];
    //Setting asset image to image view according to the image url
    [imageview setImage:[UIImage imageWithCGImage:iref]];        
};
ALAssetsLibraryAccessFailureBlock failureblock  = ^(NSError *myerror)
{
    NSLog(@"Error, cant get image - %@",[myerror localizedDescription]);
}; 

if(imageurl != nil)
{
ALAssetsLibrary *assetLibrary=[[ALAssetsLibrary alloc] init];
[assetLibrary assetForURL:imageurl resultBlock:resultblock    failureBlock:failureblock];      
}
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Vipin
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1 Answers1

6

enabling "location services "is a requirement for using the AssetsLibrary. The reason is that any photos/videos in the Photo-Library might contain geodata. This data is not just available through ALAssetPropertyURLs, but also if you read out the raw data from the asset (by using the getBytes:fromOffset:length:error: Method of ALAssetsRepresentation). Cause there is no way to strip the geo metadata from the raw image data (in case location services are disabled), I guess the design decision was made to make "location services" mandatory for using the AssetsLibrary.

This requirement might be confusing to the user. So you need to do 2 things:

1) If the user denies access to location services, then present a clear message while your app needs this access and that the app does not actually determine the current position or any GPS/data.

2) Display clear instructions how to enable location services, once the user has pressed "NO" on the initial dialog.

Cheers,

Hendrik

holtmann
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