Question

I’m creating a UITableView that uses custom UITableViewCell classes. The UITableViewCell uses it’s own methods to lay itself out depending on the indexPath and selected index.

Code is as follows:
AgendaView.h
TableViewDelegate Methods

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

EventInfoCell *cell = [tableView dequeueReusableCellWithIdentifier:@"infoCell"];
if(cell == nil){
    cell = [[EventInfoCell alloc]initWithStyle:0 reuseIdentifier:@"infoCell"];
}

cell.frame = CGRectMake(0, 0, 320, [self tableView:tableView heightForRowAtIndexPath:indexPath]);
cell.selectedBackgroundView = nil;
cell.delegate = self;

TimerEvent *event = [_eventsArray objectAtIndex:indexPath.row];
EventInfo *info = [event valueForKey:@"eventInfo"];

NSDateFormatter *df = [[NSDateFormatter alloc]init];
[df setDateFormat:@"h:mma"];
cell.timeLabel.text = [NSString stringWithFormat:@"%@",[df stringFromDate:event.date]];

cell.titleField.text = [info title];

cell.bgImageView.frame = cell.frame;

cell.countdownLabel.text = [self getCountdown:event];

if (_selectedIndex == indexPath.row){
    [cell layoutSelected:YES editing:[tableView isEditing]];

    if ([info location]) 
        cell.locationField.text =[NSString stringWithFormat:@"@%@",[info location]];
    else
        cell.locationField.text = @"Location";

    if ([info notes]) 
        cell.notesView.text = [info notes];
    else
        cell.notesView.text = @"Notes";
}else
    [cell layoutSelected:NO editing:NO];

return cell;
}

Is this an acceptable way to layout a cell? Or should I create different cell subclasses for the different cell layouts? If it helps, the cell’s expand when touched to show more information, which is why I had the subclass handle it’s own layouts.

Images: http://tinypic.com/r/2vjpi12/6

The cells information is determined by the TimerEvent/Info assigned during tableView:cellForRowAtIndexPath.

Answer 1

I think you should instead create different UITableViewCell subclasses for each type of row. This is a sketch of how I might do it:

@interface UITableViewCell (MyTableViewSupport)
@property ( nonatomic, strong ) id value ; // value to display
+(NSString *)identifier ; // reuse identifier for this class
@end

@implementation UITableViewCell (MyTableViewSupport)

+(NSString*)identifier
{
    return NSStringFromClass( self ) ;
}

const char * sValueKey = "TableCellValue";
-(void)setValue:(id)value
{
    objc_setAssociatedObject( self, sValueKey, value, OBJC_ASSOCIATION_RETAIN_NONATOMIC ) ;
}

-(id)value
{
    return objc_getAssociatedObject( self, sValueKey ) ;
}

@end

@interface TableCellA : TableViewCell
@end

@interface TableCellB : TableViewCell
@end

@implementation TableCellA

-(void)layoutSubviews
{
    // one type of layout
}

@end

@implementation TableCellB

-(void)layoutSubviews
{
    // another type of layout
}

@end

Your table view data source (probably your view controller):

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    id value = [ self _valueForRowAtIndexPath ] ;
    Class cellClass = /// ...look up cell class based on section/row or type of value, etc.

    UITableViewCell * cell = [ tableView dequeueReusableCellWithIdentifier:cellClass.identifier ] ;
    if ( !cell )
    {
        cell = [ [ cellClass alloc ] init ] ;
    }

    cell.value = value ;
    return cell ;
}

EDIT: extended explanation of the above:

The first part of the code (the category) on UITableViewCell extends it to provide a cellIdentifier class method and a value property. Now all instances of UITableViewCell support setting/getting the “value” property, including your subclasses.

Let’s say you have to types of row, Employees and Companies. You would create EmployeeCell and CompanyCell:

@interface EmployeeCell : UITableViewCell

-(void)layoutSubviews
{
    // layout code for employee cells
}

-(void)setValue:(id)value
{
    [ super setValue:value ] ;
    // configure the subviews of this employee cell (first name label, last name label, photo, for example) based on `value`
}

@end

@implementation CompanyCell : UITableViewCell

-(void)layoutSubviews
{
    // layout code for company cells
}

-(void)setValue:(id)value
{
    [ super setValue:value ] ;

    // configure the subviews of this company cell (company name label, address label, CEO label, for example) based on `value`
}

@end