Iphone SDK : Working with the Address Book Database - Person Photo Retriever Application

In this section, we present a sample application that prompts the user to enter a query for a person. This query is used to retrieve a person with a photo and display it on the screen as shown in Figure 1

The source code for this application can be found in the PersonPhotoRetriever project available from the source downloads.

Listing 1 shows a category on UIImage to return the photo of the first person in the address book whose name matches a given query.

Figure 1. The photo retriever application.

Example 1. A category on UIImage to return the photo of the first person in the address book whose name matches a given query.

@interface UIImage (AddressBook) +(UIImage*)photoForAperson:(NSString*)_name; @end @implementation UIImage (AddressBook) // returns the image of the first person give a query +(UIImage*)photoForAperson:(NSString*)_name{ UIImage *_image = nil; ABAddressBookRef addressBook = ABAddressBookCreate(); NSArray *people = (NSArray*) ABAddressBookCopyPeopleWithName(addressBook, (CFStringRef)_name); int index = 0; while (index < [people count]){ ABRecordRef person = (ABRecordRef)[people objectAtIndex:index++]; NSData *photoData = (NSData*) ABPersonCopyImageData(person); if (photoData){ _image = [UIImage imageWithData:photoData]; [photoData release]; break; } } [people release]; CFRelease(addressBook); return _image; } @end

The photoForAperson: method takes the query text as an argument and returns the photo. It starts by creating an address book object. After that, the method ABAddressBookCopyPeopleWithName is used to perform a prefix search using the given query. The function returns an array of person records that match this query. The method then iterates through this array retrieving the image data of each person record using ABPersonCopyImageData function. If the photo data is not nil, a UIImage instance is created from this data and the image is returned.

Listing 2 shows the method triggered when the user taps the Retrieve Photo button. It simply retrieves the image view and sets it to the image if an image with the query exists. Otherwise, it displays an alert view.

Example 2. The method triggered when the user taps the Retrieve Photo button.

-(void)buttonPushed{
  NSString  *name = [(UITextField*)[self.view viewWithTag:999] text];
  UIImageView *imageView = (UIImageView*)[self.view viewWithTag:1234];
  UIImage *image = [UIImage photoForAperson:name];
  if(image){
    imageView.image = image;
    [[self.view viewWithTag:999] resignFirstResponder];
   }
  else{
    [[[UIAlertView alloc] initWithTitle:@"No Records!"
      message:[NSString stringWithFormat:@"%@ photo not found", name]
      delegate:self
      cancelButtonTitle:nil
      otherButtonTitles:@"OK", nil] show];
  }
}