Table View Not Properly Updating - objective-c

My project is a large one, and I'm not sure which code snippet is causing the problem, so I'll just describe the problem. I have an initial view that is a UITableView. This view has a navigation bar, in which one of the buttons is an "edit" button. Pressing the "edit" button sends you into a modal view controller in which there is another UITableView. This UITableView has the attribute that it is a checklist table view (in which multiple items can be selected [checked] or deselected. Once you are finished choosing your items, it saves the array of chosen objects into an NSUserDefault. Now, you are back at the original page where the array of things you chose should be displayed on the UITableView. I change the array that is feeding the UITableView it's data to the array grabbed from the NSUserDefaults. I then call [tableView reloadData] and nothing changes. I would really appreciate any tips. If you guys think you know what part of the code is causing me grief, please respond and I'll post it. Thanks (and by the way, I know I should be making the main view controller the delegate of modal view controllers). Thanks in advance.

Call [[NSUserDefaults standardUserDefaults] synchronize]; after you make changes in the modal view controller. This will save the changes.
Be sure to update the cell content each time the table row is reloaded.
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
Bleh *data = (Get your data for this row);
cell.textLabel.text = data.myValue;
cell.imageView.image = data.myImage;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier];
}
[self configureCell:cell atIndexPath:indexPath];
return cell;
}

Try to reload your tableview on viewwillappear , when you back from modelviewcontroller method calls
- (void)viewWillAppear:(BOOL)animated{
[yourTableView reloadData];
}

Related

UITableViewCell textLabel overwrites my button

Probably a simple question, but I can't find the answer.
When I set my textLabel it overwrites my Detail Disclosure button that I have in my content view of the cell, put in through the storyboard. Now it only shows when the cell is selected. My code looks like this:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"accountCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
User *user = [arr objectAtIndex:indexPath.row];
// Configure the cell...
cell.textLabel.text = [user username];
return cell;
}
When I take away cell.textLabel.text = [user username]; it shows all the time, as I want.
Any tips? Guess I gotta put some code in for my button...
Figured it out...
To understand this question, you need to understand that a UITableViewCell only has three spaces - imageView, textLabel and accessory. When you set the textLabel it overwrites everything you've created in the content area in storyboard. I had to set a a new class, with subclass UITableViewCell and set the custom IBOutlets in that one, then link in the custom class to my TableView.

ipad add tableview (only a part) to viewcontroller with storyboard

So I'm trying to add a UITableView on the lower half of my ipad app which will be used to display a search result. This is how I did it.
I added a UIView
I added a UItableView onto the UIView
I then dragged the UITableView to the ViewController so it can connect to it for delegate and datasource.
This is what it currently looks like:
(It's at that middle top row)
So I added the following onto the viewcontroller class to generate the data
# pragma mark TableView properties
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 2;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"SearchResultCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if(cell == nil)
{
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
cell.textLabel.text = #"test";
}
The debugger would go through all these but would get stuck after the "cellForRowAtIndexPath" method:
It would just go through that and would not end until I stop the whole debugging. Not really sure what's going on.
Thoughts? Maybe you guys can point me to the right direction as to how I should generate my search results.
Thanks!
I usually find it much more faster and easier to use the free Sensible TableView framework to do automatic table view searches, instead of using the regular datasource/delegate system which I could never get right.

pushing tableview results in cellForRowAtIndexPath exception

I am trying to build a multilayer xmlparser which shows data in a tableview and switches to the next view based on the selected row (most likely to the same viewcontroller).
I started with storyboard segues but as i am using dynamic cells i dont know how to create more than one push segue (because it needs to push to various viewcontrollers). So i kept the storyboard views, deleted all the segues and used the code below instead.
however it throws this exception when the new view tries to pupulate the row:
Terminating app due to uncaught exception
'NSInternalInconsistencyException', reason: 'UITableView dataSource
must return a cell from tableView:cellForRowAtIndexPath:'
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(#"index: %i", indexPath.row);
switch (indexPath.row) {
case 0:
{
DetailViewController *detailViewController = [DetailViewController alloc];
[self.navigationController pushViewController:detailViewController animated:YES];
break;
}
//...
default:
{
LayerViewController *layerViewController= [LayerViewController alloc];
[layerViewController setStartUpWithIndex:indexPath.row andLayer:layercount];
[self.navigationController pushViewController:layerViewController animated:YES];
break;
}
}
}
setStartUpWithIndex:andLayer: is my init method...
the problem does not occur when im pushing via storyboard segue with the following segue code:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
[[segue destinationViewController] setStartUpWithIndex:indexPath.row andLayer:layercount];
}
i think i am missing something the "segue" method does which i need to include in my didSelectRowAtIndexPath as cellForRowAtIndexPath: works fine in the first layer of the view.
requested edit:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"LayerCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
cell.textLabel.text = [[articles objectAtIndex:indexPath.row]objectForKey:#"HerstellerName"];
// cell.textLabel.text = #"ololol";
return cell;
}
the articles array is working btw
You aren't creating any cells. I don't know why Apple didn't include this in the default implementation, but after:
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
You need to add:
if (cell==nil){
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
Otherwise you're just relying on dequeued cells which won't exist when the tableView loads.
Edit: And if you're not using ARC, you need to wrap that alloc method with an autorelease.
You are pushing another viewController to be viewed and this next viewController has no dataSource methods implemented. This what happened.
As far as I understood, you are trying to present an xml node with a table in the way that each table row consist child nodes of presented node. selecting row with chld node gets you to next table view which presents table with child nodes of selected node.
IMO you may need only one view controller to present current xml node, which changes only data to be presented in a table and reloads the table again. So no pushing view controllers is needed. You can use then method
– reloadRowsAtIndexPaths:withRowAnimation:
for all the nodes in the table, setting animation similar to changing view controller (aka sliding old table left)

Bad EXC_BAD_ACCESS when scrolling through UITableView

I initiated a UITableView with the following code:
ProductTableView *tableProd = [[ProductTableView alloc]initWithNibName:#"ProductTableView" bundle:nil];
the xib file does exist!
Since I am displaying this table in a separate UIView I add it to this screen by:
[content addSubview:tableProd.view];
I used xcode to create a standard UITableView and set the following functions:
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 10;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
cell.textLabel.text = #"test";
return cell;
}
The table is displayed in the simulator with 10 rows filled with test. However, when I start scrolling, and the first cell leaves the screen, the simulator crashes with a EXC_BAD_ACCESS error. I tried using Instruments to detect the NSZombie and the software flaged the zombie. Unfortunately I cant trace this error back to the cause.
Does anyone have a idea what is going wrong here?
if you're adding the view of a view controller as a subview of another view controllers view, i would guess that the ProductTableView view controller is being dealloced (since adding as a subview retains the view, but not the view controller it belongs to)
add the ProductTableView view controller as a property of the container view controller so that it is retained

Add editing elements to UITableViewCell

I have a couple of rows in a table view which I like to edit.
I thought that setEditing method would give me a Edit and Delete button, but it only shows a Delete button. Because I don't have a detail view controller that's going to be pushed in didSelectRowAtIndexPath I thought I could show a couple of editing elements in the selected cell.
I need to add three buttons to specify priority on assignments: Low, High and Medium priority. This means that I have to change the height of the selected cell to make room for these buttons, I think that's rather easy to do.
What I'm wondering is if this is the correct path to choose?
I have done quite a lot research today without finding examples of how other have solved editing in a UITableViewCell. If you edit a contact in the Contacts app in the iPhone the UITableViewCells changes to enable quick and easy editing, that's what I'm looking for.
So what do you have for tips for me regarding this question?
Edit #1
My code in didSelectRowAtIndexPath is:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
Cell *selectedCell = (Cell *)[tableView cellForRowAtIndexPath: indexPath];
UIButton *btn = [UIButton buttonWithType: UIButtonTypeRoundedRect];
btn.frame = CGRectMake(0, 0, 50, 100);
btn.titleLabel.text = #"Set this item to High Priority";
btn.backgroundColor = [UIColor greenColor];
[selectedCell.contentView addSubview: btn];
self.editing = YES;
[tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject: indexPath] withRowAnimation:UITableViewRowAnimationFade];
}
Code for heightForRowAtIndexPath:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
Cell *cell = nil;
if (self.editing)
cell = (Cell *)[tableView cellForRowAtIndexPath: indexPath];
else
cell = nil;
BOOL expandCell = NO;
NSInteger expandationHeight = 0;
if (cell != nil)
{
for (UIButton *btn in cell.contentView.subviews)
{
NSLog(#"A button was found.");
expandationHeight = 70;
expandCell = YES;
}
}
return expandationHeight + heightOfOtherElements;
}
When I click at a cell nothing happends but everything becomes disabled, I can't click any elements on the hole view. This has something to do with [tableView cellForRowAtIndexPath: indexPath], because if I uncomment that line the UI does not become disabled.
What am I doing wrong?
That's not too complicated though it requires some stuff.
You want to change the content of one cell or of all cells?
To specify a specific height for one cell, use the - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath delegate method.
It is called for each cell each time the table view is displayed. If you want to change a single row, call reloadRowsAtIndexPaths:withRowAnimation: method from UITableView. If you want to update all cells, simply use - (void)reloadData method.
You can also access a specific cell using - (UITableViewCell *)cellForRowAtIndexPath:(NSIndexPath *)indexPath method from UITableView. Then you can reconfigure it to add various elements on it, as you want.
Thus, when a cell is selected, check whether you have to edit it or not, then :
update your cell get from cellForRowAtIndexPath
be sure your method tableView:heightForRowAtIndexPath: will return the good height
tell the table view to update the view using reloadRowsAtIndexPaths:withRowAnimation: