I wanted to add a profile photo to user collection when creating a user. I was thinking of doing [user setValue:imageData forAttribute:@"photo"] and then with help of KCSLinkedAppdataStore store it mybkexperience. But it fails with error JSON serialization not supported for NSConcreteMutableData.

[user setValue:imageData forAttribute:@"photo"];
KCSLinkedAppdataStore* store = [KCSLinkedAppdataStore storeWithCollection:[KCSCollection userCollection] options:nil];
[store saveObject:user withCompletionBlock:^(NSArray *objectsOrNil, NSError *errorOrNil) {
    if (errorOrNil ==  nil) {
        //was successful!
    } else {
         //failed
    }
} withProgressBlock:nil];

Uploading the file separately and then set its fileid to an attribute in user collection works. What is the best way of extending KCSUser? I am currently using class extension.

migrating to different version just to add a profile photo seems too hectic.