I'm filling a tableview with data from a server. I fill it well, but I have a function to display the details of each row in another screen, but when I push back, the app Crash, but I don't know why!!
This is my function:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.section == 1) {
NSUInteger i, totalNumberOfItems = [gestiones count];
NSUInteger newNumberOfItemsToDisplay = MIN(totalNumberOfItems, numberOfItemsToDisplay + kNumberOfItemsToAdd);
NSMutableArray *indexPaths = [[NSMutableArray alloc] init];
for (i=numberOfItemsToDisplay; i<newNumberOfItemsToDisplay; i++) {
[indexPaths addObject:[NSIndexPath indexPathForRow:i inSection:0]];
}
numberOfItemsToDisplay = newNumberOfItemsToDisplay;
[tableView beginUpdates];
[tableView insertRowsAtIndexPaths:indexPaths withRowAnimation:UITableViewRowAnimationTop];
if (numberOfItemsToDisplay == totalNumberOfItems) {
[tableView deleteSections:[NSIndexSet indexSetWithIndex:1] withRowAnimation:UITableViewRowAnimationTop];
}
[tableView endUpdates];
// Scroll the cell to the top of the table
NSIndexPath *scrollPointIndexPath;
if (newNumberOfItemsToDisplay < totalNumberOfItems) {
scrollPointIndexPath = indexPath;
} else {
scrollPointIndexPath = [NSIndexPath indexPathForRow:totalNumberOfItems-1 inSection:0];
}
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 200000000), dispatch_get_main_queue(), ^(void){
[tableView scrollToRowAtIndexPath:scrollPointIndexPath atScrollPosition:UITableViewScrollPositionTop animated:YES];
});
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}else{
Gestion *ges = [gestiones objectAtIndex:indexPath.row];
DetalleGestionViewController *vcc = [[DetalleGestionViewController alloc] initWithNibName:#"DetalleGestionViewController" bundle:nil];
vcc.gestion = ges;
[self.navigationController pushViewController:vcc animated:YES];
NUEVA_GESTION = YES;
[gestiones removeAllObjects];
}
}
With "NUEVA_GESTION" I prepare the app to reload the table data.
Can someone help me?
Related
Here is my code. And yesterday it works just fine. But this morning, it doesn't work.
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if (indexPath.row == 0) {
RSDrug *drug = [[RSDrug alloc]init];
[drugArray insertObject:drug atIndex:0];
NSIndexPath *ip = [NSIndexPath indexPathForRow:1 inSection:0];
[tableView insertRowsAtIndexPaths:#[ip] withRowAnimation:UITableViewRowAnimationAutomatic];
}
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return drugArray.count + 1;
}
I have tried to add some code like beginUpdates/endUpdates, or I delete insertRowsAtIndexPaths, just use reloadData.
But same result. When the app runs to insertRowsAtIndexPaths or reloadData, it stuck, no response.
So I need some help. How to solve this?
Found the problem..........A stupid mistake
There are two UITextFields in the added cell, and they all have the same leftView, my code is like this:
UIImageView *leftImage = [[UIImageView alloc]initWithImage:[UIImage imageNamed:#"img"]];
field_1.leftView = leftImage;
field_2.leftView = leftImage;
I never know that I can't reuse the leftView. If I set the leftImage to field1, I can't set it to field2 anymore.
When I changed to this, it works again.
field_1.leftView = [[UIImageView alloc]initWithImage:[UIImage imageNamed:#"img"]];
field_2.leftView = [[UIImageView alloc]initWithImage:[UIImage imageNamed:#"img"]];
Try this sequence...
NSMutableArray *indexPaths=[[NSMutableArray alloc]init];
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
[tableView beginUpdates];
RSDrug *drug = [[RSDrug alloc]init];
[drugArray insertObject:drug atIndex:0];
if (indexPath.row == 0) {
[indexPaths removeAllObjects];
[indexPaths addObject:[NSIndexPath indexPathForRow:indexPath.row++ inSection:0]]; // here inserting row index=1;
[tableViewMenuList insertRowsAtIndexPaths:indexPaths withRowAnimation:UITableViewRowAnimationFade];
}
[tableView endUpdates];
}
Have you tried this?
RSDrug *drug = [[RSDrug alloc]init];
[drugArray insertObject:drug atIndex:0];
[tableView beginUpdates];
// indexpath inserted is with the index 0 same with the `insertObject: `
NSIndexPath *ip = [NSIndexPath indexPathForRow:0 inSection:0];
[tableView insertRowsAtIndexPaths:#[ip] withRowAnimation:UITableViewRowAnimationAutomatic];
//here is what i use to do instead of #[]
//[tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:ip] withRowAnimation:UITableViewRowAnimationAutomatic];
[tableView endUpdates];
EDIT
Your code are working fine. i tested it. here..
Code:
Output:
Log:
Check the tested code above if you have omitted something.
I think the problem is the delegates of your table, make sure that your table have the delegate for both UITableViewDataSource & UITableViewDelegate.
Hope this is helpful.. Cheers.. :)
I'm currently working on an implementation of an inline UIDate picker inside of a UITableViewCell.
I'm able to show and hide this picker cell when I select the cell directly above where that cell should be inserted, which is the behavior that I expect. However, the app crashes if I select any other cells in the table view:
*** Assertion failure in -[UITableView _endCellAnimationsWithContext:], /SourceCache/UIKit_Sim/UIKit-3318.16.14/UITableView.m:1582
After looking at the accepted answer to this SO question, I added an exception breakpoint, and I've found out that the app is crashing at the call to [tableView endUpdates]; in didSelectRowAtIndexPath:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[self.tableView deselectRowAtIndexPath:indexPath animated:YES];
// Check to see if the "Only Alert From" row was selected. The cell with the picker should be below this one.
if (indexPath.section == TimeOfDaySection && indexPath.row == HourTimeZoneRow && self.timePickerIsShowing == NO){
[tableView beginUpdates];
[self showTimePicker];
[tableView endUpdates];
} else{
[tableView beginUpdates];
[self hideTimePicker];
[tableView endUpdates];
[self.tableView deselectRowAtIndexPath:indexPath animated:YES];
}
[self.tableView deselectRowAtIndexPath:indexPath animated:YES];
}
That said, I'm not sure how to proceed. If I comment out the call to [tableView endUpdates];, the app won't crash when other cells are selected, BUT the cell with the picker view won't hide. Does anyone have any suggestions? Thank you!
EDIT: Below is my code for showTimePicker and hideTimePicker:
- (void)showTimePicker
{
self.timePickerIsShowing = YES;
self.timePicker.hidden = NO;
//Create the index path where we insert the cell with the picker
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:HourTimeZoneRow + 1 inSection:TimeOfDaySection];
[self.tableView beginUpdates];
[self.tableView insertRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationFade];
[self.tableView endUpdates];
self.timePicker.alpha = 0.0f;
[UIView animateWithDuration:0.25 animations:^{
self.timePicker.alpha = 1.0f;
//This is the row where the picker cell should be inserted
[self.tableView reloadRowsAtIndexPaths:#[[NSIndexPath indexPathForRow:HourTimeZoneRow + 1 inSection:TimeOfDaySection]] withRowAnimation:UITableViewRowAnimationFade];
[self.tableView reloadData];
}];
}
- (void)hideTimePicker {
self.timePickerIsShowing = NO;
self.timePicker.hidden = YES;
//Create the index path where we delete the cell with the picker
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:HourTimeZoneRow + 1 inSection:TimeOfDaySection];
[self.tableView beginUpdates];
//Delete the picker row
[self.tableView deleteRowsAtIndexPaths:#[indexPath] withRowAnimation:UITableViewRowAnimationFade];
[self.tableView endUpdates];
[UIView animateWithDuration:0.25
animations:^{
self.timePicker.alpha = 0.0f;
}
completion:^(BOOL finished){
self.timePicker.hidden = YES;
}];
}
EDIT 2: After reading this SO thread, I believe the problem may be with my numberOfRowsInSection method:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
switch (section) {
case NotificationsSection:
return TotalPreferencesRows;
break;
case RedZoneSection:
return TotalRedZoneRows;
break;
case TimeOfDaySection:
if (self.timePickerIsShowing) {
return TotalTimeOfDayRows + 1;
}
// else if (self.timePickerIsShowing == NO){
// return TotalTimeOfDayRows;
// }
else{
return TotalTimeOfDayRows;
}
return TotalTimeOfDayRows;
break;
default:
return 0;
break;
}
}
Not sure if this is the source of the crash, but it's not recommended to call beginUpdates multiple times which you're doing in
[tableView beginUpdates];
[self showTimePicker];
[tableView endUpdates];
because showTimePicker calls [self.tableView beginUpdates];
The problem is in your didSelectRowAtIndexPath, you call the hide method even though it might not be showing. Make the else clause into an else if, like this:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[self.tableView deselectRowAtIndexPath:indexPath animated:YES];
// Check to see if the "Only Alert From" row was selected. The cell with the picker should be below this one.
if (indexPath.section == TimeOfDaySection && indexPath.row == HourTimeZoneRow && self.timePickerIsShowing == NO){
[tableView beginUpdates];
[self showTimePicker];
[tableView endUpdates];
} else if (indexPath.section == TimeOfDaySection && indexPath.row == HourTimeZoneRow && self.timePickerIsShowing == YES){
[tableView beginUpdates];
[self hideTimePicker];
[tableView endUpdates];
[self.tableView deselectRowAtIndexPath:indexPath animated:YES];
}
[self.tableView deselectRowAtIndexPath:indexPath animated:YES];
}
I'm trying to insert a row at the top of UITableView, but it crashes in the last line where I declare the endUpdating. This is the code I'm using and I'm using a button outside the table to insert row.
[comments insertObject:comment atIndex:0];
[self.commentsTableView beginUpdates];
NSIndexPath *newIndexPath = [NSIndexPath indexPathForRow:0 inSection:0];
[self.commentsTableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
[self.commentsTableView endUpdates]; //here crashes with "assertion failure"
I know I can just do insert in array and reload, but I want to do it with animation.
Thank you in advance.
This is my cell for row method
- (UITableViewCell *)tableView:(UITableView *)theTableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = #"CommentCell";
// Similar to UITableViewCell, but
ListingCommentTableViewCell *cell = (ListingCommentTableViewCell *)[theTableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (cell == nil) {
cell = [[ListingCommentTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
}
cell.commenterLabel.text = [[comments objectAtIndex:indexPath.row] objectForKey:#"user"];
[cell.commenterLabel sizeToFit];
cell.commentLabel.text = [[comments objectAtIndex:indexPath.row] objectForKey:#"text"];
[cell.commentLabel sizeToFit];
cell.lineView.frame = CGRectMake(5 , cell.commentLabel.frame.origin.y + cell.commentLabel.frame.size.height+ 5, cell.frame.size.width-20, 1);
cell.dateLabel.text = [Utils formatCommentDate:[[comments objectAtIndex:indexPath.row] objectForKey:#"createdOn"]];
return cell;
}
THis is my cell height method
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
int height = [Utils findHeightForText:[[comments objectAtIndex:indexPath.row] objectForKey:#"teksti"] havingWidth:screenWidth - 40 andFont:[UIFont fontWithName:#"Ubuntu" size:14]];
height += 25;
return height + 5;
}
and my number of rows method
- (NSInteger)tableView:(UITableView *)theTableView numberOfRowsInSection:(NSInteger)section
{
return [comments count];
}
This is how I insert objects to UITableView with animation.
-(void)updateMethod {
[self.commentsTableView beginUpdates];
NSIndexSet *indexSet = [NSIndexSet indexSetWithIndex:0];
NSIndexPath *newIndexPath = [NSIndexPath indexPathForRow:0 inSection:0];
[comments insertObjects:[NSArray arrayWithObjects:comment, nil] atIndexes:indexSet];
[self.commentsTableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
[self.commentsTableView endUpdates];
}
You should check numberOfRowsInSection and be sure it reflect your comments.count
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return comments.count;
}
Also all UI updates must be done on the main thread, if you call your update method in different thread there is a change you can see that error.
You should update data source array inside animation block:
[self.commentsTableView beginUpdates];
[comments insertObject:comment atIndex:0];
NSIndexPath *newIndexPath = [NSIndexPath indexPathForRow:0 inSection:0];
[self.commentsTableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
[self.commentsTableView endUpdates];
I am having problems with deleting rows from table view. I am using the code below when the delete button in the row was pressed:
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:control.tag-100 inSection:0];
[resultList removeObjectAtIndex:indexPath.row];
[resultView beginUpdates];
[resultView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
[resultView endUpdates];
//[resultView reloadData];
First row was deleted successfully but then, indexes were not correct. So when I delete the last row, it gives index out of bounds exception.
The cell generation code is:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"personalizeTableCell";
PersonalizeCell *cell = (PersonalizeCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
cell = [[PersonalizeCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
cell.title.text = #"text";
cell.rateView.tag = indexPath.row + 100;
return cell;
}
Where am I wrong?
UPDATE:
for (NSInteger j = 0; j < [venuesTableView numberOfSections]; ++j)
{
for (NSInteger i = 0; i < [venuesTableView numberOfRowsInSection:j]; ++i)
{
PersonalizeCell* cell = (PersonalizeCell*)[venuesTableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:i inSection:j]];
cell.rateView.tag = 100 + i;
}
}
solved my problem. Thanks to Nenad M.
Assuming your [NSIndexPath indexPathForRow:control.tag-100 inSection:0]; returns the right index path....
Did you try moving the removeObjectAtIndex call inside the begin-/end-updates "bracket"?:
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:control.tag-100 inSection:0];
[resultView beginUpdates];
[resultList removeObjectAtIndex:indexPath.row];
[resultView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
[resultView endUpdates];
UPDATE:
Obviously your cell.rateView.tag become wrong, after youe delete your first cell.
So after every deletion (i.e. every removeObjectAtIndex...) you must re-iterate over your remaining tableview-cells an re-assign the proper tag-value (cell.rateView.tag = indexPath.row + 100)! Otherwise your [NSIndexPath indexPathForRow:control.tag-100 inSection:0]; will return a wrong indexPath, therefore leading to your out of bounds error!
Re-assigning the tag-values:
You don't have to reload the entire table, just loop through the remaining cells an re-assign the tag-value after [resultView endUpdates];:
NSMutableArray *cells = [[NSMutableArray alloc] init];
for (NSInteger j = 0; j < [tableView numberOfSections]; ++j)
{
for (NSInteger i = 0; i < [tableView numberOfRowsInSection:j]; ++i)
{
[cells addObject:[tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:i inSection:j]]];
}
}
Now do:
for (PersonalizeCell* cell in cells)
{
cell.rateView.tag = // new calculated tag
}
(Or do the re-assignment even in the inner-loop of the first code-snippet directly.)
Here's some really typical code for the whole process, two lines from the table in the example:
Note that facebookRowsExpanded is a class variable you must have:
if ( [theCommand isEqualToString:#"fbexpander"] )
{
NSLog(#"expander button......");
[tableView deselectRowAtIndexPath:indexPath animated:NO];
NSArray *deleteIndexPaths;
NSArray *insertIndexPaths;
facebookRowsExpanded = !facebookRowsExpanded;
// you must do that BEFORE, not AFTER the animation:
if ( !facebookRowsExpanded ) // ie, it was just true, is now false
{
deleteIndexPaths = [NSArray arrayWithObjects:
[NSIndexPath indexPathForRow:2 inSection:0],
[NSIndexPath indexPathForRow:3 inSection:0],
nil];
[tableView beginUpdates];
[tableView
deleteRowsAtIndexPaths:deleteIndexPaths
withRowAnimation: UITableViewRowAnimationMiddle];
[tableView endUpdates];
}
else
{
insertIndexPaths = [NSArray arrayWithObjects:
[NSIndexPath indexPathForRow:2 inSection:0],
[NSIndexPath indexPathForRow:3 inSection:0],
nil];
[tableView beginUpdates];
[tableView
insertRowsAtIndexPaths:insertIndexPaths
withRowAnimation: UITableViewRowAnimationMiddle];
[tableView endUpdates];
}
// DO NOT do this at the end: [_superTableView reloadData];
return;
}
NOTE: your code for numberOfRowsInSection must use facebookRowsExpanded
(it will be something like "if facebookRowsExpanded return 7, else return 5")
NOTE: your code for cellForRowAtIndexPath must use facebookRowsExpanded.
(it has to return the correct row, depending on whether or not you are expanded.)
I have an app with a table view that expands/collapses sections, following the example in Apple's Table View Animations & Gestures sample app. I am running into problems when an item is added to a closed section: after that, the section no longer opens, and I get an exception when I try to open and then close it.
I've traced this to some strange behaviour in the open/close methods:
-(void)sectionHeaderView:(SectionHeaderView*)sectionHeaderView sectionOpened:(NSInteger)section {
if (![[sectionHeaderArray objectAtIndex:section] isOpen]) {
[[sectionHeaderArray objectAtIndex:section] setIsOpen:YES];
NSLog(#"self.tableView: %#", self.tableView);
id <NSFetchedResultsSectionInfo> sectionInfo = [[self.fetchedResultsController sections] objectAtIndex:section];
NSInteger countOfRowsToInsert = [sectionInfo numberOfObjects];
NSMutableArray *indexPathsToInsert = [[NSMutableArray alloc] init];
for (NSInteger i = 0; i < countOfRowsToInsert; i++) {
[indexPathsToInsert addObject:[NSIndexPath indexPathForRow:i inSection:section]];
}
// Apply the updates.
[self.tableView beginUpdates];
NSLog(#"Count of rows to insert: %d", [indexPathsToInsert count]);
NSLog(#"Rows before insert: %d", [self.tableView numberOfRowsInSection:section]);
[self.tableView insertRowsAtIndexPaths:indexPathsToInsert withRowAnimation:UITableViewRowAnimationTop];
NSLog(#"Rows after insert: %d", [self.tableView numberOfRowsInSection:section]);
[self.tableView endUpdates];
}
}
-(void)sectionHeaderView:(SectionHeaderView*)sectionHeaderView sectionClosed:(NSInteger)section {
if ([[sectionHeaderArray objectAtIndex:section] isOpen]) {
[[sectionHeaderArray objectAtIndex:section] setIsOpen:NO];
NSInteger countOfRowsToDelete = [self.tableView numberOfRowsInSection:section];
if (countOfRowsToDelete > 0) {
NSMutableArray *indexPathsToDelete = [[NSMutableArray alloc] init];
for (NSInteger i = 0; i < countOfRowsToDelete; i++) {
[indexPathsToDelete addObject:[NSIndexPath indexPathForRow:i inSection:section]];
}
[self.tableView beginUpdates];
NSLog(#"Count of rows to delete: %d", [indexPathsToDelete count]);
NSLog(#"Rows before delete: %d", [self.tableView numberOfRowsInSection:section]);
[self.tableView deleteRowsAtIndexPaths:indexPathsToDelete withRowAnimation:UITableViewRowAnimationTop];
NSLog(#"Rows after delete: %d", [self.tableView numberOfRowsInSection:section]);
}
[self.tableView endUpdates];
}
}
The log messages show that, on open (insert rows), >0 rows are being inserted, and yet the row count for that section stays 0:
2012-03-31 13:36:17.454 QuickList7[5523:fb03] Count of rows to insert: 3
2012-03-31 13:36:17.454 QuickList7[5523:fb03] Rows before insert: 0
2012-03-31 13:36:17.454 QuickList7[5523:fb03] Rows after insert: 0
This sets up an inconsistent state between the table and data source, and then when I try to "collapse" the section, I get the following exception:
2012-03-31 13:48:35.783 QuickList7[5523:fb03] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid table view update. The application has requested an update to the table view that is inconsistent with the state provided by the data source.'
How can I insert 3 rows, and still end up with 0 rows?
Thanks,
Sasha
I found the problem! It was actually in the fetchedResultsController's change handler. It was responding to changes to closed sections, which left the table in a bad state, and out of sync with the data source. So I added a check for each update to only insert/delete/update rows if the containing section is open.
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath
{
UITableView *tv = self.tView;
switch(type) {
case NSFetchedResultsChangeInsert:
if ([[sectionHeaderArray objectAtIndex:newIndexPath.section] isOpen]) {
[tv insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
}
break;
case NSFetchedResultsChangeDelete:
if ([[sectionHeaderArray objectAtIndex:indexPath.section] isOpen]) {
[tv deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
break;
case NSFetchedResultsChangeUpdate:
if ([[sectionHeaderArray objectAtIndex:indexPath.section] isOpen]) {
[self configureCell:[tv cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
}
break;
case NSFetchedResultsChangeMove:
if ([[sectionHeaderArray objectAtIndex:indexPath.section] isOpen]) {
[tv deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
if ([[sectionHeaderArray objectAtIndex:newIndexPath.section] isOpen]) {
[tv insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade];
}
break;
}
}
In my app I've implemented a similar behavior in a very different way because I was running into this type of problem a lot.
I have a table with MenuNameCells, MenuItemCells and a static cell at the bottom. Only one menu is expanded at a time, and tapping a MenuNameCell expands or collapses that menu. Since I keep the MenuNameCell in its own section and the MenuItemCells in another, I only have to insert/delete entire sections when I reload the table.
Here's my table's data source:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// number of menus, plus 1 if a menu is open, plus 1 static cell
return [self.restaurant.menus count]+(self.menu != nil ? 1 : 0)+1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// if this section is our selected menu, return number of items, otherwise return 1
int numberOfRowsInSection = ([self indexPathIsInMenuItemSection:section] ? [[self.menu items] count] : 1);
return numberOfRowsInSection;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
if (indexPath.section == [tableView numberOfSections]-1) {
// ... set up and return static cell
}
if ([self indexPathIsInMenuItemSection:indexPath.section]) {
// ... set up and return menu item cell
} else {
// ... set up and return menu name cell
}
}
and my table's delegate:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
// return if it's a static cell
if (indexPath.section==[tableView numberOfSections]-1)
return;
// if it's a menu name cell, close open menu and maybe expand this menu
if (![self indexPathIsInMenuItemSection:indexPath.section]) {
BOOL reset = self.menu == m;
if (reset) [self reloadTableView:self.tableView withMenu:nil animated:YES autoscroll:NO];
else [self reloadTableView:self.tableView withMenu:m animated:YES autoscroll:YES];
}
}
There were a couple of helpers mentioned in there:
- (BOOL)indexPathIsInMenuItemSection:(NSInteger)section
{
// returns YES if section refers to our MenuItemCells
int indexOfMenu = [self.restaurant getIndexOfMenu:self.menu];
return indexOfMenu != -1 && section == indexOfMenu+1;
}
- (void)reloadTableView:(UITableView *)tableView withMenu:(Menu *)menu animated:(BOOL)animated autoscroll:(BOOL)autoscroll
{
int oldIndex = [self.restaurant getIndexOfMenu:self.menu];
int newIndex = [self.restaurant getIndexOfMenu:menu];
[tableView beginUpdates];
if (oldIndex != -1) {
// index of [section for items] is oldIndex+1
[tableView deleteSections:[NSIndexSet indexSetWithIndex:oldIndex+1] withRowAnimation:UITableViewRowAnimationTop];
}
if (newIndex != -1) {
// index for [section for items] is newIndex+1
[tableView insertSections:[NSIndexSet indexSetWithIndex:newIndex+1] withRowAnimation:UITableViewRowAnimationTop];
[self setMenu:menu];
} else {
// no new menu
[self setMenu:nil];
}
[tableView endUpdates];
if (autoscroll) [self autoscroll];
}
- (void)autoscroll
{
if (self.menu != nil) {
int section = [self.restaurant getIndexOfMenu:self.menu];
if (section != -1) {
NSUInteger indexes[] = {section,0};
NSIndexPath *indexPath = [NSIndexPath indexPathWithIndexes:indexes length:2];
[self.tableView scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionTop animated:YES];
}
}
}
Since my data is loaded asynchronously elsewhere, I have this controller set up to receive an NSNotification, but it should work just as well to call this on viewDidAppear:
[self reloadTableView:self.tableView withMenu:self.menu animated:YES autoscroll:YES];
I hope this helps! Let me know if I can clarify any of it.