I have an Edit button in my navigation bar, and I have an table view.
My edit button calls an -editAction method.
And then, I have this piece of code to delete a cell, but I don't know how I can make the edit button to call this code...or how the edit button can let the table view display those red delete circles for every cell, which then trigger this:
// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
    if (editingStyle == UITableViewCellEditingStyleDelete) {
        // Delete the managed object at the given index path
        NSManagedObject *eventToDelete = [eventsArray objectAtIndex:indexPath.row];
        [managedObjectContext deleteObject:eventToDelete];
        // Update Event objects array and table view
        [eventsArray removeObjectAtIndex:indexPath.row];
        [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:YES];
        // Commit the change
        NSError *error;
        if (![managedObjectContext save:&error]) {
            // Handle the error
        }
    } 
}