Question

I’d like to create a custom UITableViewCell subclass that loads content asynchronously using a URL connection. I’ve got a UITableViewCell subclass that handles all of this and a Nib file that defines the layout of the cell, but I’m having trouble linking the two. Here’s the code I’m using in tableView:cellForRowAtIndexPath:

static NSString *FavCellIdentifier = @"FavCellIdentifier";

FavouriteCell *cell = [tableView dequeueReusableCellWithIdentifier:FavCellIdentifier];

if (cell == nil)
{
    cell = [[[FavouriteCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:FavCellIdentifier] autorelease];
}

cell.requestURL = [NSURL URLWithString:[NSString stringWithFormat:@"%@?%@=%i", URL_GET_POST_STATUS,
                                           URL_PARAM_SERIAL,
                                           [[self.favourites objectAtIndex:indexPath.row] intValue]]];

return cell;

This gives a request URL to the UITableViewCell subclass, which handles loading in the setRequestURL method.

In the FavouriteCell class I’ve kept the initWithStyle:reuseIdentifier: method as is, and in the Nib I’ve set FavCellIdentifier as the identifier, and FavouriteCell as the class. Now how do I make the FavouriteCell class load the Nib?

Answer 1

In order to use the nib/xib file, you’re going to have to instantiate the FavouriteCell differently.

Try this:

1. Make sure you’ve changed the type of your UITableViewCell to be a subclass of FavouriteCell instead of the default UITableViewCell in your xib. Do this by:
   • Clicking on the cell in the objects pane of Interface Builder.
   • Then, go to the Identity Inspector tab and make sure the Class selection under Custom Class lists FavouriteCell.
2. Change the File's Owner property to be the UIViewController where you want to display your custom UITableViewCell (pretty much same process as step #1).
3. Add an IBOutlet property of type FavouriteCell to your UIViewController. Name it whatever you like (I’m going to call it cell).
4. Back in the xib of the UITableViewCell, connect the IBOutlet for the cell property in File’s Owner to your custom UITableViewCell.
5. Use this code to load the cell programmatically:

---

- (FavouriteCell *)tableView:(UITableView *)tableView 
       cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *CellId = @"FavCellId";
    FavouriteCell *cell = [tableView dequeueReusableCellWithIdentifier:CellId];
    if (!cell) {
        // Loads the xib into [self cell]
        [[NSBundle mainBundle] loadNibNamed:@"FavouriteCellNibName" 
                                      owner:self 
                                    options:nil];
        // Assigns [self cell] to the local variable
        cell = [self cell];
        // Clears [self cell] for future use/reuse
        [self setCell:nil];
    }
    // At this point, you're sure to have a FavouriteCell object
    // Do your setup, such as...
    [cell setRequestURL:[NSURL URLWithString:
                  [NSString stringWithFormat:@"%@?%@=%i", 
                      URL_GET_POST_STATUS, 
                      URL_PARAM_SERIAL, 
                      [[self.favourites objectAtIndex:indexPath.row] intValue]]
     ];
    return cell;
}