Definitive tableView:heightForRowAtIndexPath: solution - iphone

Question

Ok, This is an old issue almost every iOS developer has struggled with. Many answers on the subject are a available.
However I still haven't found a really practical, generic solution for calculating a UITableViewCell's height in tableView:heightForRowAtIndexPath:.
I understand how the layout mechanism of UITableView works (it calculates the height of the whole table before actually laying out any cells).
I also understand that one basically has to anticipate everything that will happen in UITableViewCells layout method using for example sizeWithFont:... methods on NSString.
I assume that the style of the cell is UITableViewCellStyleSubtitle to begin with (we can get more generic later!).
These would be my requirements:
the cell might be in a grouped or plain tableView
the system version might be iOS 6 or iOS 7+
an image might or might not be set in cell.imageView
an accessory view might or might not be set
cell.textLabel might or might not contain text.
cell.detailTextLabel might or might not contain text.
fonts might be customized
the labels might be multi-line
the table width is arbitrary (portrait, landscape, iPad...)
the number of cells is limited (probably some dozen)
In most cases this kind of dynamic cell would be used in short lists (maybe some kind of detail view) so I think it would be viable to pre-calculate the cells like described here: https://stackoverflow.com/a/8832778/921573
I am looking for an implementation for calculating the cell height that satisfies the given requirements.
I'd be very happy if anyone could share some insights & experience - thanks in advance!

Answer 1

You could keep a single dummy cell in your table view's delegate and let it calculate its own required size.

Answer 2

The best way to make custom cells with different heights is:
make a NSMutableArray for cells:
#property (nonatomic,retain)NSMutableArray* cellsArray;
then in m.:
the first method which call is
-(float)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
make your cell here:
-(float)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
if (!self.cellsArray) {
self.cellsArray = [[NSMutableArray alloc]init];
}
ListCell* cell = [[ListCell alloc] initWithFrame:CGRectMake(x, y, width, height)];
// IMPLEMENT your custom cell here, with custom data, with custom,different height:
// after add this cell to your array:
[self.cellsArray addObject:cell];
// IMPORTANT STEP: set your cell height for the new height:
cell.frame = CGRectMake(cell.frame.origin.x, cell.frame.origin.y, 303, yourLastItemInCell.frame.origin.y + yourLastItemInCell.frame.size.height);
return cell.frame.size.height;
}
after you got the custom cells with different heights :
#pragma mark - conform to delegates
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return 10;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
return self.cellsArray[indexPath.row];
}
I hope it helps !
EDIT:
tableView = [[UITableView alloc] initWithFrame:frame style: UITableViewStylePlain];
tableView.delegate = self;
tableView.dataSource = self;
tableView.backgroundColor = [UIColor clearColor];
tableView.separatorStyle = UITableViewCellSeparatorStyleNone;