Fetch Images Using Facebook IOS SDK

If you don't know how to configure facebook-ios-sdk in your xcode project , please follow the link

For fetching the user’s image we need to get the access token for the currently logged in user . For that follow the link for login with facebook. (https://developers.facebook.com/docs/facebook-login/ios)

Note : Facebook requires read Permissions for accessing images so change loginButton.readPermissions as Below in  -viewDidLoad()  method of  ViewController .

- (void)viewDidLoad

{
    [super viewDidLoad];
    FBSDKLoginButton *loginButton = [[FBSDKLoginButton alloc]init];
    loginButton.delegate =self;
    loginButton.center = self.view.center;
    loginButton.readPermissions =  @[@"public_profile", @"email", @"user_photos"];
    [self.view addSubview:loginButton];
}

Now your application is ready for accessing the facebook api .

For fetching facebook images uploaded by user can be fetched by calling the -(void)loadFacebookImages() function on click event of Load More button.

-(void)loadFacebookImages

{

     /* create dictionary with parameters to pass in the api call. */

    NSMutableDictionary *dictParameters  =  [[NSMutableDictionary alloc]initWithDictionary:@{@"fields": @"images{source}",@"limit":@"5"}];
    
    if (afterPageToken) {
        [dictParameters setObject:afterPageToken forKey:@"after"];
    }
    
     /* create request with parameters */
    FBSDKGraphRequest *request = [[FBSDKGraphRequest alloc]
                                  initWithGraphPath:@"/me/photos/uploaded"
                                  parameters: dictParameters
                                  HTTPMethod:@"GET"];

    /* make the api call */
    [request startWithCompletionHandler:^(FBSDKGraphRequestConnection *connection, id result, NSError *error) {
        
        responseDict = [NSJSONSerialization JSONObjectWithData:[NSJSONSerialization dataWithJSONObject:result options:0 error:&error] options:0 error:&error];

        afterPageToken = [[[responseDict objectForKey:@"paging"] objectForKey:@"cursors"] objectForKey:@"after"];
        
        if (afterPageToken) {
            [arrImageUrls addObjectsFromArray:[responseDict objectForKey:@"data"]];
            [_collectionView reloadData];
        }else  {
            afterPageToken = @"";
            return ;
        }
    }];
}

Here, we have provided parameters {@"fields": @"images{source}",@"limit":@"5"} where fields : images{source} is simply mean to provide the urls for the images . limit : 5 is to limit the number of results returned.

afterPageToken is variable of type NSString .

arrImageUrls is variable of type NSMutableArray.

• Create the PhotosViewController  subclass of UIViewController. Add the CollectionView to PhotosViewController.
• Drag CollectionViewCell to CollectionView.

• Create CollectionCell subclassing UICollectionViewCell and assign it to collectionviewcell .

• Implement UICollectionViewDataSource  , UICollectionViewDelegate  methods in PhotosViewController  .

-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath

{
    CollectionCell *cell ;

    cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"collection" forIndexPath:indexPath];
    
    if (!cell) {
        cell = [[CollectionCell alloc]init];
    }    

    NSDictionary *dictImageData =[arrImageUrls objectAtIndex:indexPath.row];
    NSArray *imageArray = [dictImageData objectForKey:@"images"];
    NSDictionary *newDict = [imageArray lastObject];    

    [cell.imgFacebook sd_setImageWithURL:[NSURL URLWithString:[newDict objectForKey:@"source"]] placeholderImage:nil];
   
    return cell;
}