Modifying static cells outside cellForRowAtIndexPath without creating new cells - iphone

Question

So I get that its typically frowned upon to modify a cell outside of the cellForRowAtIndexPath but here is what I have:
I have a static table that is used as an index of questions (1-33). Each row has a question on it and a detail disclosure indicator. All of this is manually entered in on the stoyboard.
I have a file that lists each question and some properties such as if the question has been answered.
When this screen loads (viewDidAppear) I want to check if each of these questions have been loaded and if so switch the detail indicator to a checkmark.
Now this works, for the first 5 cells. If I go to a question and come back, then even more cells are checked (even if the questions have not been answered). Is this undefined behavior because I am accessing it outside of cellForRowAtIndexPath?
Here is the code I'm using to access and change the cell:
-(void) viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
if (question1Answered)
{
UITableViewCell *cell1 = [self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:3]];
[cell1 setAccessoryType:UITableViewCellAccessoryCheckmark];
}
}
Again, it does work for the first 5 elements, then the rest will not change no matter what I do. Then if I go to a question and return it shows more with it selected. Strange behavior...
EDIT: I just noticed that the above code works but it only updates the cells that are currently on the screen. So if I scroll down, leave and come back all the visible cells will have the check mark. Is there a way to force a refresh of all the cells, even if they aren't visible?
Thanks for any and all help...
-David

Answer 1

This is similar to another question I answered few days ago. See stackoverflow.com/a/11770387/1479411
Use delegate method. Put any code that modifies the cell content and [self.tableView reloadData] in the delegate method after returning from the other view controller.

Answer 2

You should not update cell from viewDidAppear.
Instead you should reload data from viewDidApeear.
-(void) viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
if (question1Answered)
{
//This will call your tableview's delegate for visible cells
[self.tableView reloadData];
}
}
And inside cellForRowAtIndexPath, you should take a decision to assign accessory type.

Answer 3

U should first update your model then update your UI according to the model state.
For example if your model is an array of Question object, and each question has some hasBeenAnswered boolean.
Then the only thing u should do in viewDidAppear is to call [self.tableView reloadData], this will update your table view because cellForRowAtIndexPath will be called and set the cells according to your model state.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"CellIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if(cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
// configure the cell according to your model state
Question *question = [self.questions objectAtIndex:indexPath.row];
// check if this question has been answered
if (question.hasBeenAnswered) {
// if yes - set a checkmark
[cell setAccessoryType:UITableViewCellAccessoryCheckmark];
}
else {
// if not - set to none (or whatever u want)
[cell setAccessoryType:UITableViewCellAccessoryNone];
}
return cell;
}