Use two different custom tableview cells in same tableview - ios

Question

I'm using one type of Custom Table View Cell, but when other data is posted to my Table View, I want it to be displayed in a different Custom Table View Cell in the same table.
For example, I've created a chat in my Table View. However when certain details are posted, I want a separate cell design to display these details. See my code below so far.
My question: How can I write, "If field_swaptime in self.messages is empty, display ChatTableViewCell - if it contains data, display SwapDetailTableViewCell" ?
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *ChatTableIdentifier = #"ChatTableViewCell";
static NSString *ChatTableIdentifier2 = #"SwapDetailTableViewCell";
NSDictionary *data = [self.messages objectAtIndex:indexPath.row];
if ( [data objectForKey:#"field_swaptime"] == nil ) {
NSLog(#"THIS IS DATA %#", data);
ChatTableViewCell *cell = (ChatTableViewCell *)[tableView dequeueReusableCellWithIdentifier:ChatTableIdentifier];
if (cell == nil)
{
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"ChatTableViewCell" owner:self options:nil];
cell = [nib objectAtIndex:0];
}
NSString *userName = [data objectForKey:#"name"];
[cell.sendingUser setText:userName];
NSString *messageBody = [data objectForKey:#"body"];
[cell.messageDisplayed setText:messageBody];
NSString *timeReceived = [data objectForKey:#"published at"];
NSLog(#"Message Received at %#", timeReceived);
[cell.timeStamp setText:timeReceived];
return cell;
}
else {
SwapDetailTableViewCell *cell = (SwapDetailTableViewCell *)[tableView dequeueReusableCellWithIdentifier:ChatTableIdentifier2];
if (cell == nil)
{
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"SwapDetailTableViewCell" owner:self options:nil];
cell = [nib objectAtIndex:0];
}
NSString *Time = [data objectForKey:#"field_swaptime"];
NSLog(#"This is time %#", Time);
[cell.startTime setText:Time];
NSString *TimeEnd = [data objectForKey:#"field_endswaptime"];
[cell.endTime setText:TimeEnd];
return cell;
}
}

Answer 1

You are basically looking to write your initial if as:
NSDictionary *data = [self.messages objectAtIndex:indexPath.row];
//
// if self.messages is nil, then data will be nil and we'll display
// a ChatTableViewCell as before. If data is valid, but there is no
// value associated with "field_swaptime", then again, we'll display
// a ChatTableViewCell. However, if self.messages IS valid and
// there IS a value associated with "field_swaptime" key, then the
// if clause fails, and we execute the else and return a
// SwapDetailTableViewCell.
//
if ( !data || ![data objectForKey:#"field_swaptime"] } {
ChatTableViewCell *cell = (ChatTableViewCell *)[tableView dequeueReusableCellWithIdentifier:ChatTableIdentifier];
if (cell == nil)
{
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"ChatTableViewCell" owner:self options:nil];
cell = [nib objectAtIndex:0];
}
NSString *userName = [data objectForKey:#"name"];
[cell.sendingUser setText:userName];
NSString *messageBody = [data objectForKey:#"body"];
[cell.messageDisplayed setText:messageBody];
NSString *timeReceived = [data objectForKey:#"published at"];
NSLog(#"Message Received at %#", timeReceived);
[cell.timeStamp setText:timeReceived];
return cell;
}
else {
SwapDetailTableViewCell *cell = (SwapDetailTableViewCell *)[tableView dequeueReusableCellWithIdentifier:ChatTableIdentifier2];
if (cell == nil)
{
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"SwapDetailTableViewCell" owner:self options:nil];
cell = [nib objectAtIndex:0];
}
NSString *Time = [data objectForKey:#"field_swaptime"];
[cell.startTime setText:Time];
NSString *TimeEnd = [data objectForKey:#"field_endswaptime"];
[cell.endTime setText:TimeEnd];
return cell;
}
Bonus: if self.messages is valid, and data is valid, then you already have data and don't need to multiple calls to [self.messages objectAtIndex:indexPath.row]. (you should do a bounds sanity check on self.messages.count against indexPath.row before calling objectAtIndex:indexPath.row, but the defensive coding part is up to you to put together)
Objective C is pretty nifty in that calling a method on nil object, just returns nil. So, it is perfectly valid to ignore whether self.messages is valid or not, and just retrieve the data it contains. If it is valid (and your index is in bounds of the array), then a valid NSDictionary will be returned that you can use throughout the if/else clause.

Answer 2

The type of cell you get is determined by the type you register to correspond with the identifier. So, when you're setting up the table (say, in viewDidLoad)...
UINib *nib = [UINib nibWithNibName:#"ChatTableViewCell" bundle:nil]; // bundle:nil means main bundle
[self.tableView registerNib:nib forCellReuseIdentifier:#"ChatTableIdentifier"];
UINib *nib2 = [UINib nibWithNibName:#"OtherTableViewCell" bundle:nil];
[self.tableView registerNib:nib2 forCellReuseIdentifier:#"OtherIdentifier"];
Then, in cellForRowAtIndexPath, you use the modern dequeue method, dequeueReusableCellWithIdentifier:forIndexPath:, which never returns nil and always returns an instance built from the nib you registered earlier...
// generically
NSString *identifier = (/*some condition*/)? #"ChatTableIdentifier" : #"OtherIdentifier";
// or alternatively, given the condition in your comment...
NSString *identifier = (!data[#"field_swaptime"])? #"ChatTableIdentifier" : #"OtherIdentifier";
UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:identifier forIndexPath:indexPath];
// now cell is one of your two custom classes, built from their respective nibs.
Based on the same condition, you can cast cell to either kind, and configure it...
if (/*same condition as identifier*/) {
ChatTableViewCell *chatCell = (ChatTableViewCell *)cell;
// do your config for this type here
} else {
OtherTableViewCell *otherTypeCell = (OtherTableViewCell *)cell;
// do your config for this other type here
}
return cell;