I tried several ways but it seems I'm missing something..
Here is the code I use:
- (void)configureView
{
// Update the user interface for the detail item.
if (self.detailItem) {
for (int idx=0; idx<16; idx++) {
NSIndexPath *indexPath = [[NSIndexPath alloc] initWithIndex:idx];
[self.tableView cellForRowAtIndexPath:indexPath].detailTextLabel.text = [param objectAtIndex:idx];
}
self.detailDescriptionLabel.text = [self.detailItem description];
}
}
I call this on viewDidLoad. My tableview has 16 static cells, and I'm using standard "Subtitle" type cell, so no customization needed on that front. textLabel.text is filled at design time. Also my tableview is in a tableViewController. I also tried with standard population of tableview but it seems static cells don't agree with that way.
What am I doing wrong?
#jrturton I did some changes to see what's going on:
I added these three lines under for line to see if there's anything there:
UITableView *tv = self.tableView;
UITableViewCell *cell = [tv cellForRowAtIndexPath:[NSIndexPath indexPathForRow:idx inSection:0]];
NSString *label = [[NSString alloc] initWithString:cell.textLabel.text];
First of all tv is assigned correctly, I can see that. But other than that cell and label comes empty. Even tv has no row information it seems..
Could it be because tableview has datasource and delegate assigned to the tableviewcontroller.. I think I heard it shouldn't be like that or something...
#jrturton Here it is:
Hope this helps.
Some logging would quicky show you that your index path is not valid and therefore no cell is being returned.
To create an NSIndexPath for use in a UITableView, use this method:
[NSIndexPath indexPathForRow:idx inSection:0];
The index path has to contain a row and section for the table to understand it.
You also need to call this from viewWillAppear: rather than viewDidLoad, the static table is not populated that early on. And you must call [super viewWillAppear:animated] first!
Related
I know that dequeueReusableCellWithIdentifier:forIndexPath is called by tableView method inside the tableviewcontroller. And if I understand correctly, tableView method is called several times until all the cells are populated. But what I don't know is where do you get the value for the parameter IndexPath? I want to use dequeueReusableCellWithIdentifier:forIndexPath for a method that I created because I want to access my cell to copy some values of its properties.
NOTE:
I already populated my cell, which means that I successfully used the method tableView.
(Edit) ADDITIONAL INFO:
I'm trying to create a profile and edit profile tableviews. Inside the profile tableview, I displayed the name, address, contact#, etc., of the user. Also, I have a segue called edit profile. In the edit profile, I have textfields for each category (name, address, etc.). What I want to do is, if I edit the contents of the textfields, I should be able to display the new contents in my profile tableview. An example case would be: in the profile view I'm displaying -> name:human, address:earth (each in its own cell). Now if I go to editprofile tableview, I will edit the contents such that -> name:alien, address:mars. After that, there is a button called 'apply' to end editing of contents and go back to profile tableview. If I go back to profile view, the display should now be name:alien, address:mars and not name:human, address:earth.
Here is some code if it's any help. The code is called by a button in tableviewcontroller. "MyCell" is the class of my cell. This code is not working properly. I hope someone can help me fix this.
- (IBAction)updateCopies:(id)sender {
static NSString *ident = #"MyCell";
NSIndexPath *indexPath;
//create cell
MyCell *cell = [self.tableView dequeueReusableCellWithIdentifier:ident forIndexPath:indexPath];
//create variable for accessing cells
int row = [indexPath row];
_labelValues[row] = cell.textField.text
}
You should only use dequeueReusableCellWithIdentifier when you need to supply the table view with a cell to display. If you want to get the UITableViewCell object at a certain index, you should use cellForRowAtIndexPath.
Your problem
What you really need is a model class. You can then pass this to the edit controller, which changes the properties. Then when you return to the tableView, you can reload it and display the new properties.
What you could also do is create a delegate protocol for your edit profile controller, something like EditProfileViewControllerDelegate with something like:
protocol EditProfileViewControllerDelegate {
- (void)editProfileViewController:(EditProfileViewController *)controller didUpdateName:(NSString *)name address:(NSString *)address;
}
You can implement this delegate in your table view controller and use it to update the values when the text is changed. However, this quickly becomes unwieldy, I would not recommend it over using a proper model class.
You can get indexPath using CGPoint..You can use dequeueResusableCell for reusability of the cell..
- (IBAction)updateCopies:(id)sender {
CGPoint position = [sender convertPoint:CGPointZero
toView:self.tableView];
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:position];
//create variable for accessing cells
MyCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];
int row = [indexPath row];
_labelValues[row] = cell.textField.text
}
Hope it helps you..
Use this
- (IBAction)updateCopies:(id)sender {
MyCell *parentCell = (MyCell *)sender.superview;
while (![parentCell isKindOfClass:[MyCell class]]) { // iOS 7 onwards the table cell hierachy has changed.
parentCell = parentCell.superview;
}
UIView *parentView = parentCell.superview;
while (![parentView isKindOfClass:[UITableView class]]) { // iOS 7 onwards the table cell hierachy has changed.
parentView = parentView.superview;
}
UITableView *tableView = (UITableView *)parentView;
NSIndexPath *indexPath = [tableView indexPathForCell:(MyCell *)parentCell];
NSLog(#"indexPath = %#", indexPath);
}
Well I got what you want to accomplish.
Firstly, there is a delegate which is being called when you click/select a cell and go to the Edit Profile page. That delegate is
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
///
}
Make a global variable, say selectedIndexPath which holds the current cell index path which is being edited. Update this value each time when you go to edit profile page.
Like this
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
selectedIndexPath = indexPath;
// code to go to edit page...
}
Now in your updateCopies Method, do like this
- (IBAction)updateCopies:(id)sender {
//get the existing cell with the indexPath
[self.tableView beginUpdates];
[self.tableView reloadRowsAtIndexPaths:#[selectedIndexPath]];
[self.tableView endUpdates];
//rest of your code goes here...
}
Using this code
- (IBAction)testAdd:(id)sender
{
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:self.numberOfRows inSection:0];
[self.tableView beginUpdates];
self.numberOfRows++;
[self.tableView insertRowsAtIndexPaths:#[indexPath]withRowAnimation:UITableViewRowAnimationBottom];
[self.tableView endUpdates];
}
I'm able to add a new item to a tableView via an 'add' button on the app. This basically adds an item identical to the item already on the table that preceded it.
For example, I have a tableview with the first row displaying a string "TEST", hitting add adds another row that displays "TEST".
I would like to be able to pass in a custom value for the new row, so hitting add outputs a row with say "NEWTHING".
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"UITableViewCell" forIndexPath:indexPath];
// Configure the cell...
cell.textLabel.text = self.val2;
return cell;
}
My data source is actually another view controller that takes user inputs and sends it to my tabelViewController, with the text for the item as "val2".
What I actually want to achieve is the ability to hit add, go back to the user input view controller, get the new data and send it back to my tableViewController to be displayed
What you're asking, is the kinda stuff that is to be done in -cellForRowAtIndexPath: (most of the times, it depends on the way you have designed your datasource) but if it doesn't matter to you, then you can do:
- (IBAction)testAdd:(id)sender
{
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:self.numberOfRows
inSection:0];
self.numberOfRows++;
[self.tableView beginUpdates];
[self.tableView insertRowsAtIndexPaths:#[indexPath]
withRowAnimation:UITableViewRowAnimationBottom];
[self.tableView endUpdates];
UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];
[cell.textLabel setText:#"NEWTHING"];
}
But note that when you scroll far up/down and return to this cell, it will most probably show "TEST" (that's where -cellForRowAtIndexPath: will show it's true purpose)
PS: Include your -cellForRowAtIndexPath: method implementation in the question if you want to proceed further
EDIT:
Your -cellForRowAtIndexPath is too static... in the sense that it simply sets self.val2 to cell.textLabel.
Lets say you start with 10 rows, -cellForRowAtIndexPath will be called 10 times and every time, it will set self.val2 onto the current cell's textLabel.
Now... when you add one row (on a button tap), the -cellForRowAtIndexPath will be called for the 11th cell and the same* text will be set to it.
*this technically happened but we quickly changed the cell's text
Basically, the tableView doesn't know how to differentiate between an existing cell and a new added cell because the datasource itself is not dynamic.
To direct the tableView on how to handle different cells, we need to create a more dynamic datasource.
There are different approaches use but I'd generally do it this way:
- (void)viewDidLoad
{
[super viewDidLoad];
self.val2 = #"TEST";
//declare "NSMutableArray *arrDatasource;" globally
//this will be the soul of the tableView
arrDatasource = [[NSMutableArray alloc] init];
int i_numberOfCells = 10;
//populate beginning cells with default text
for (int i = 0; i < i_numberOfCells; i++) {
NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
[dictionary setObject:self.val2 forKey:#"displayText"];
[arrDatasource addObject:dictionary];
}
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
//return number of objects in arrDatasource
return arrDatasource.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"UITableViewCell" forIndexPath:indexPath];
//pick up value for key "displayText" and set it onto the cell's label
[cell.textLabel setText:arrDatasource[indexPath.row][#"displayText"]];
//this will be dynamic in nature because you can modify the contents
//of arrDatasource and simply tell tableView to update appropriately
return cell;
}
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
//make indexPath of new cell to be created
NSIndexPath *indexPathNEXT = [NSIndexPath indexPathForItem:arrDatasource.count inSection:0];
//add the appropriate contents to a dictionary
NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
[dictionary setObject:#"NEWTHING" forKey:#"displayText"];
//add the dictionary object to the main array which is the datasource
[arrDatasource addObject:dictionary];
//add it to tableView
[self.tableView beginUpdates];
[self.tableView insertRowsAtIndexPaths:#[indexPathNEXT]
withRowAnimation:UITableViewRowAnimationAutomatic];
[self.tableView endUpdates];
//this ends up calling -cellForRowAtIndexPath for the newly created cell
//-cellForRowAtIndexPath shows the text (you put in the dictionary in this method above)
}
PS: -cellForRowAtIndexPath: is called whenever cell updates or refreshes or needs to be displayed and so this method needs to be implemented properly
this is my first question. I wouldn't be asking but after reading the documentation and trying lots of code from stack overflow I'm still stumped. I've just started learning code recently, so yes, I am a dumb-ass and wouldn't be surprised if I've made some fundamental error(s).
What I'm trying to do: in a custom cell's textField, a number is entered and on exit the saveGoal method is called in the CustomCellClass.m (code shown below). The saveGoal method creates a goalsArray from the text file of previous entries (if there's no data the text file is created. I omitted that code because it works). This is where it gets difficult (for me). I need the indexPath of the cell which called the method so I can insert the user entry... But I don't know how to get the cell object to use as a parameter in indexPathForCell.
- (IBAction)saveGoal:(id)sender {
// Saving the user entry in a string
self.goalString = [NSString stringWithFormat:#"%#\n",self.goal.text];
// Instance variables
NSError *err = nil;
NSMutableArray *goalsArray = [NSMutableArray arrayWithContentsOfURL:self.goalsURLMethod];
// If there is data in the text file
NSIndexPath *indexPath = [[NSIndexPath alloc] init];
// Ideally I'd like to do something like this (There is an IBOutlet from the
// table view in the storyboard to a tableView property).
indexPath = [self.tableView indexPathForCell: UNKNOWN CELL PARAMETER];
// Then based on the indexPath I can insert or replace objects in the array
if(indexPath == 0) {
// masterful code
} else {
// If it's another row, replace the object. Something like this:
[goalsArray replaceObjectAtIndex: indexPath.row withObject: self.goalString];
[goalsArray writeToURL:self.goalsURLMethod atomically:YES];
// Then update the view
[self.tableView reloadData];
}
}
}
A solution would be much appreciated!
If you have a custom cell, add a property to it:
#property (strong, nonatomic) NSIndexPath *indexPath;
and set it when you return the cell for display. Now the cell has access to the required information.
Aside:
Not that you're going to use it any more, but don't do this:
NSIndexPath *indexPath = [[NSIndexPath alloc] init];
indexPath = [self.tableView indexPathForCell: UNKNOWN CELL PARAMETER];
because creating an instance just to destroy it in the next statement is wasteful
Or you could just do it like this into the action method of your choice:
CGPoint hitPoint = [sender convertPoint:CGPointZero toView:self.tableView];
NSIndexPath *hitIndex = [self.tableView indexPathForRowAtPoint:hitPoint];
I am populating a tableview from data that is received from a server. The data is a list of user activities within a given timeframe. One such activity is "Login". I do not wish to populate my tableview with this string but I'm not sure how to skip it when populating my tableview.
Here is how I populate the cell
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{ static NSString *CellIdentifier = #"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
#try{
NSManagedObject *object = [self.fetchedResultsController objectAtIndexPath:indexPath];
NSString *action = [object valueForKey:#"theActionName"];
if ([action isEqualtoString:#"Login"]) {
return cell;
}
return cell;
}#catch (NSException *ex) {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
return cell;
}
}
As you can see I tried using return cell but as you probably know it gives me a blank cell when the table is displayed. I'm sure there is a simple line of code for this but I came up blank with the search terms I used. Could someone please enlighten me! Thanks!
P.S. you may be thinking I am not putting anything in any of the cells but I pulled out a bunch of code to keep this short.
UPDATE:
Thanks for the heads up on "isEqualtoString:" Everything worked fine with "isEqual" but I changed it given that I received so many suggestions to do so. But this is not what I am asking.
To be more clear if I had an array containing the terms: view, view, login, view. When my tableview was populated I would have 4 cells that said; view, view, login, view. I simply want to ignore the term login so that I would have 3 cells that all said view. Thanks!
There can be many way to do this.
I Belive that UITabelView should display what its datasource (here datasource is self.fetchedResultsController) contains.
What you can do is create another NSArray from self.fetchedResultsController which does not contain this object.
Try this:
NSMutableArray *newSource = [[NSMutableArray alloc] init];
for(int i = 0; i < self.fetchedResultsController.count ; i++)
{
NSManagedObject *object = [self.fetchedResultsController objectAtIndexPath:indexPath];
NSString *action = [object valueForKey:#"theActionName"];
if (![action isEqual:#"Login"])
{
[newSource addObject:action];
}
}
[tableView reloadData];
Now use newSource instead of self.fetchedResultsController
You might think that using one more array is not good. But believe it it is far easier than using the same array with condition. You don't have to worry about that condition when you perform some operation with your UITableView like remove object by using indexpath.
try using if ([action isEqualToString:#"Login"])
When you want to compare strings you need to use this isEqualToString .
Change this line
if ([action isEqualToString:#"Login"]) {
return cell;
}
You are using the wrong function to compare your input string and the given data variable.
They both are NSString objects so use :
if([action isEqualToString:#"Login"])
{
//enter your code here
}
#Ben : I am assuming that you have registered you cell through nib as you are using dequeueReusableCellWithIdentifier.
Make your tableview content as "Dynamic prototype" (You can see this in Attributes Inspector of table view) and change your table view cell style as custom (You can see this in Attributes Inspector of tableview cell).
I've created a UITableview with sections that are clickable. When you click on them,
they "expand" to reveal cells within them
the clicked section scrolls to the top of the view.
I calculate all of the indexpaths to insert/delete the necessary cells and then insert them with the following code:
[self.tableView beginUpdates];
[self.tableView insertRowsAtIndexPaths:pathsToOpen withRowAnimation:insertAnimation];
[self.tableView deleteRowsAtIndexPaths:pathsToClose withRowAnimation:deleteAnimation];
[self.tableView endUpdates];
[self.tableView scrollToRowAtIndexPath:[pathsToOpen objectAtIndex:0] atScrollPosition:UITableViewScrollPositionTop animated:YES];
There's only one problem- the sections below the selected section are hidden. The first screen-shot shows how the tableview should look. The second screen-shot shows how it actually looks.
If you scroll up (so the hidden sections are offscreen) and then scroll back down, the hidden sections are brought back (once again visible). My guess as to why this is happening is the following:
The insert/delete animations are happening at the same time as the scrollToRowAtIndexPath and it is confusing the TableView. If I hadn't done scrollToRowAtIndexPath sections 3 & 4 would have been offscreen - and so the tableView somehow still thinks they are offscreen. UITableview hides cells/sections that are offscreen as an optimization. If I call scrollToRowAtIndexPath with a dispatch_after with 2 seconds, then sections 3 & 4 are displayed correctly.
So I think I know why this is happening, but I don't know how to fix/override this UITableview optimization. Actually, if I implement scrollViewDidEndScrollingAnimation and then add a breakpoint in this function, the app displays sections 3 & 4 correctly (that's how I got the first screen-shot). But once continuing from this function, the cells disappear.
The full project can be downloaded here
Additional implementation details: Sections are legitimate UITableView sections. I've added a tapGestureRecognizer that triggers a delegate callback to the tableview. Included below is the entire method that opens the sections.
- (void)sectionHeaderView:(SectionHeaderView *)sectionHeaderView sectionOpened:(NSInteger)sectionOpened
{
// Open
sectionHeaderView.numRows = DefaultNumRows;
sectionHeaderView.selected = YES;
NSMutableArray *pathsToOpen = [[NSMutableArray alloc] init];
for (int i = 0; i < sectionHeaderView.numRows; i++)
{
NSIndexPath *pathToOpen = [NSIndexPath indexPathForRow:i inSection:sectionOpened];
[pathsToOpen addObject:pathToOpen];
}
// Close
NSMutableArray *pathsToClose = [[NSMutableArray alloc] init];
if (openSectionHeader)
{
for (int i = 0; i < openSectionHeader.numRows; i++)
{
NSIndexPath *pathToClose = [NSIndexPath indexPathForRow:i inSection:openSectionHeader.section];
[pathsToClose addObject:pathToClose];
}
}
// Set Correct Animation if section's already open
UITableViewRowAnimation insertAnimation = UITableViewRowAnimationBottom;
UITableViewRowAnimation deleteAnimation = UITableViewRowAnimationTop;
if (!openSectionHeader || sectionOpened < openSectionHeader.section)
{
insertAnimation = UITableViewRowAnimationTop;
deleteAnimation = UITableViewRowAnimationBottom;
}
openSectionHeader.numRows = 0;
openSectionHeader.selected = NO;
openSectionHeader = sectionHeaderView;
[self.tableView beginUpdates];
[self.tableView insertRowsAtIndexPaths:pathsToOpen withRowAnimation:insertAnimation];
[self.tableView deleteRowsAtIndexPaths:pathsToClose withRowAnimation:deleteAnimation];
[self.tableView endUpdates];
[self.tableView scrollToRowAtIndexPath:[pathsToOpen objectAtIndex:0] atScrollPosition:UITableViewScrollPositionTop animated:YES];
}
From what I can tell, the problem is occurring when returning a section view that's already been used. Instead of:
- (UIView *)tableView:(UITableView*)tableView viewForHeaderInSection:(NSInteger)section
{
return [self.sectionHeaderViews objectAtIndex:section];
}
I get no problem if I create a new view each time:
- (UIView *)tableView:(UITableView*)tableView viewForHeaderInSection:(NSInteger)section{
SectionHeaderView *sectionHeaderView = [self.tableView dequeueReusableCellWithIdentifier:SectionHeaderView_NibName];
sectionHeaderView.textLabel.text = [NSString stringWithFormat:#"Section %d", section];
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:sectionHeaderView action:#selector(handleTap:)];
[sectionHeaderView addGestureRecognizer:tapRecognizer];
sectionHeaderView.section = section;
sectionHeaderView.delegate = self;
return sectionHeaderView;
}
It's possible this is occurring because you're using [self.tableView dequeueReusableCellWithIdentifier:SectionHeaderView_NibName]; to create section headers and hold on to them in an array, which I don't think UITableViewCell was created for, but I'm not certain. You may want to consider foregoing UITableViewCell for section views and instead use something else (perhaps a UIImageView with a UILabel). Or you can just not store the Section Views in an array...the way you currently have your code set up, you don't need the array and creating a new view is trivial enough you don't need to worry about it.
#AaronHayman's answer works (and IMO the accept and bounty should go to him, as it stands - this just didn't fit in a comment!), but I would go further - you shouldn't be using a cell at all for section header, and you shouldn't be using the dequeue mechanism to essentially load a nib.
Section header view's aren't supposed to be cells, and you may get unforseen effects by using them in place of regular views, particularly if they are deqeueued - the table is keeping a list of these reusable cells when you do that, and recycles them when they go off screen, but your section headers aren't reusable, you have one per section.
In your sample project, I changed the superclass of SectionHeaderView to be a plain UIView, and changed your createSectionHeaderViews method to load directly from the nibs there:
NSMutableArray *sectionHeaderViews = [[NSMutableArray alloc] init];
UINib *headerNib = [UINib nibWithNibName:SectionHeaderView_NibName bundle:nil];
for (int i = 0; i < 5; i++)
{
SectionHeaderView *sectionHeaderView = [[headerNib instantiateWithOwner:nil options:nil] objectAtIndex:0];
sectionHeaderView.textLabel.text = [NSString stringWithFormat:#"Section %d", i];
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:sectionHeaderView action:#selector(handleTap:)];
[sectionHeaderView addGestureRecognizer:tapRecognizer];
sectionHeaderView.section = i;
sectionHeaderView.delegate = self;
[sectionHeaderViews addObject:sectionHeaderView];
}
self.sectionHeaderViews = sectionHeaderViews;
I also commented out the register for reuse line from your viewDidLoad. This prevents the section headers from disappearing.