Reloading UITableView - iphone

I've read some of the other posts but haven't found the right solution that seems to work in my case. I've got a UITableViewController class that is instantiated from the Main App Delegate and it controls other views that get pushed into the UINavigationController instance created from the App Delegate.
On the UINavigationToolBar I have a UISegmentedControl button that is split in two pieces, Factory Loads and User Loads. I have an action method attached to the SegmentedControl to detect when the button is pressed and that method is inside the UIViewController Class. My goal is to have the view reload with the contents of a new dictionary that is constructed from a plist file in the app bundle. I have the dictionary loaded, and the keys to be displayed set up in the respective data formats, but when I try to reload the UITableView, it crashes.
This is the last code I tried to get to work inside my action method, but it still doesn't function as intended.
- (void) action:(id)sender {
UISegmentedControl *segment = (UISegmentedControl *) sender;
if ([segment selectedSegmentIndex] == 1)
{
NSLog(#"User Load Selected");
NSString *userLoadFilePath = [[NSBundle mainBundle] pathForResource:#"UserLoads" ofType:#"plist"];
NSDictionary *userLoadDictionary = [[NSDictionary alloc] initWithContentsOfFile:userLoadFilePath];
NSArray *allKeys = [userLoadDictionary allKeys];
keys = allKeys;
dictionary = userLoadDictionary;
[[self tableView] reloadData];
}
else if ([segment selectedSegmentIndex] == 0)
{
NSLog(#"Factory Load Selected");
NSString *factoryLoadFilePath = [[NSBundle mainBundle] pathForResource:#"AlliantPowder" ofType:#"plist"];
NSDictionary *factoryLoadDictionary = [[NSDictionary alloc] initWithContentsOfFile:factoryLoadFilePath];
NSArray *allKeys = [factoryLoadDictionary allKeys];
keys = allKeys;
[[self tableView] reloadData];
}
}
I'm calling [[self tableView] reloadData] in an attempt to retrieve the actual table contained within the UIViewController to try to get the table to reload, but no luck. Any help is appreciated, and if more code is needed please ask. Thanks!
Andrew
------- Edit -----------
Here is the new code in reference to Chip's ideas. The issue is still not resolved and the app still crashes.
- (void) action:(id)sender {
// Create an instance of UISegmentedControl and set it as the sending event.
UISegmentedControl *segment = (UISegmentedControl *) sender;
// Detect which button was pressed and load a new dictionary appropriately
// Checking if userLoads was selected
if ([segment selectedSegmentIndex] == 1)
{
NSLog(#"User Load Selected");
keys = userKeys;
[[self tableView] reloadData];
}
// Checking if factoryLoads was selected
else if ([segment selectedSegmentIndex] == 0)
{
NSLog(#"Factory Load Selected");
keys = [dictionary allKeys];
[[self tableView] reloadData];
}
[segment release];
}

I would pre-load the dictionaries and hold them as ivars in the controller class.
I am betting that the loading of the dictionary contents is not complete, so you are in effect calling reloadData while the data is changing which is causing your crash.
Also, the read is an expensive option and you are loading each time the segementControl changes state.

Related

My didSelectRowAtIndexPath function causes memory leak

My first post here. Seems I have run into a bit of a memory leak problem.
I have a tab bar with two columns, one for salad and one for sushi. In each tab I also have a tableview that displays the different food choices. When the user presses one of the cells the app takes the user to a more detailview that displays a larger image and some info about the chosen food menu.
But when I run leaks I get a 98,5% leak on the following line.
[self.navigationController pushViewController: detail animated: YES];
if I release detail after this line, the app crashes.
Here is the rest of the function code:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *message = nil;
NSMutableString *image_string = nil;
DetailViewController *detail = [self.storyboard instantiateViewControllerWithIdentifier:#"detailview"];
if(tableView == SushiTable)
{
message = [sushiNames objectAtIndex:indexPath.row];
image_string = [NSMutableString stringWithString:[sushiImages objectAtIndex:indexPath.row]];
}
if(tableView == SaladTable)
{
message = [saladNames objectAtIndex:indexPath.row];
image_string = [NSMutableString stringWithString:[saladImages objectAtIndex:indexPath.row]];
}
[image_string deleteCharactersInRange: [image_string rangeOfString: #"_small"]];
NSMutableString *temp_str = [[message copy] autorelease];
NSString *final = [[[temp_str stringByReplacingOccurrencesOfString:#" " withString:#"_"]
stringByReplacingOccurrencesOfString:#"รค" withString:#"a"]
lowercaseString];
detail.food_name = message;
detail.image_name = image_string;
detail.food_info_key = final;
[tableView deselectRowAtIndexPath:indexPath animated:YES];
[self.navigationController pushViewController: detail animated: YES];
detail = nil;
}
EDIT:
I saw also that in my viewDidLoad function in DetailViewController the following line has a memory leak, don't know if it's maybe related.
food_image.image = [UIImage imageNamed:image_name];
EDIT2:
Also I'm running on the simulator.
Try it.
[self.navigationController pushViewController: detail animated: YES];
[detail release];
detail = nil;
When you push an object.Now it is added into navigation stack array, Now array owner of this object
so you should need release object which you are added in an array.
Declare the detail globally and release it in dealloc:. It may work.

does reload tabledata affect cellForRowAtIndexPath

I am currently trying to set up my tableview, when its first loaded I call my connection class which in turn calls my parser class then inside my parser class I call a method in my ViewController, which is the original view that is being set up. This method is passed an array which will be used latter.
The method passes the array to an array variable in this ViewController, in this method I then call
[self.tableView reloadData];
and what I am wanting that to do is reload cellForRowAtIndexPath so that it will go through my logic (if statements) and check if ([returnedArray count] != 0){ then do its thing.. but the thread never makes it back to this delegate method, which in turn never makes it back to the if statment.
MORE INFO :)
So first of all, when the the ViewController loads
tableView:cellForRowAtIndexPath: is called and sets up my UITableView that all looks perfect, it then calls my NSURLConnection method which connects to my server downloads all of the data and then passes that over to my parser class. From there my parser dose its thing, and everything is fine.
This is what the code looks like in my tableView:cellForRowAtIndexPath:, method
//..
if (indexPath.row == 0){
if ([FilterArray count] == 0){
[cellActivityIndicator startAnimating];
//-- Start NSURLConnection
EngineRequests *engineRequests = [[EngineRequests alloc] init];
[engineRequests initalizePacketVariables];
}
if ([FilterArray count] != 0){
[cellActivityIndicator stopAnimating];
cell.accessoryView = nil; //hides activity indicator
cell.userInteractionEnabled = YES;
cell.backgroundColor = [UIColor whiteColor];
UILabel *label1;
label1 = (UILabel *)[cell viewWithTag:1];
label1.textColor = [UIColor darkGrayColor];
UILabel *label2;
label2 = (UILabel *)[cell viewWithTag:2];
label2.textColor = [UIColor darkGrayColor];
//...etc
Inside my parser class's parserDidEndDocument method I am passing the NSArray back to the MainView.
- (void)parserDidEndDocument:(NSXMLParser *)parser
{
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"%K like %#",#"ISCHECKED",#"T"];
NSArray *filteredArray = [parsedDataArrayOfDictionaries filteredArrayUsingPredicate:predicate];
//call method in VieController1 to pass array over
SearchViewController *searchViewController = [[SearchViewController alloc] init];
[SearchViewController initFilterArray:filteredArray];
}
So then I head back over to my VC1 and the method that I have declared in the .h and then obviously in the .m file
and this is all of the code that I have in it.
#pragma - Reciver methods
-(void)initFilterArray:(NSArray*)array
{
//initalise array variable for use in latter views
FilterArray = array;
//reload to make cell white
[self.tableView reloadData];
// NSLog(#"%#", FilterArray);
}
While debugging the code the thread makes it to this method and runs everything.. if I uncomment that NSLog, it displays my filitered array and everything. However for some reason the reloadData dose not seem to call tableView:cellForRowAtIndexPath:.. I know this because I have debugged it with breakpoints etc.
So... hopefully this added information will help you help me :)
[self.tableView reloadData];
it will call the delegate methods.
if it isn't, you can check if self.tableView is linked to the tableView you want to reload.

Array nil (even when addObject:) [duplicate]

This question already has answers here:
Closed 11 years ago.
Possible Duplicate:
addObject: to array not working (array still nil)
EVERYTHING UPDATED
This app is a table view with a tab bar controller. I am logging the count of the array: arrayOfFavourites and even though i add an object is continues to have a nil value, my relating code, all objects shown are allocated and initialized in the code (previous or present) some are instances and some are properties:
ListViewController.m:
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(#"TOUCHED CELL!");
// Push the web view controller onto the navigation stack - this implicitly
// creates the web view controller's view the first time through
[[self navigationController] pushViewController:webViewController animated:YES];
// Grab the selected item
entry = [[channel items] objectAtIndex:[indexPath row]];
if (!entry) {
NSLog(#"!entry");
}
// Construct a URL with the link string of the item
NSURL *url = [NSURL URLWithString:[entry link]];
// Construct a request object with that URL
NSURLRequest *req = [NSURLRequest requestWithURL:url];
// Load the request into the web view
[[webViewController webView] loadRequest:req];
// Take the cell we pressed
// IMPORTANT PART
CELL = [tableView cellForRowAtIndexPath:indexPath];
[webViewController setItem:entry];
webViewController = nil;
webViewController = [[WebViewController alloc] init];
[entry release];
}
WebViewController.m:
You shake to favorite a cell
-(void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event
{
cellToPassOn = nil;
NSLog(#"Favouriting"); // YES I KNOW SPELLING
// This is pretty simple, what we do is we take the cell we touched and take its title and link
// then put it inside an array in the Favourites class
Favourites *fav = [[Favourites alloc] init];
ListViewController *list = [[ListViewController alloc] init];
[self setCellToPassOn: [list CELL]];
if (!item) {
NSLog(#"NILLED ITEM");
}
[[fav arrayOfFavourites] addObject:[item autorelease]];
[fav setCell: cellToPassOn];
}
Favourites.m:
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
NSLog(#"ROWS NO.");
NSLog(#"%i", [arrayOfFavourites count]);
return [arrayOfFavourites count];
}
Favourites:
A CLASS, ON TAB BAR CONTROLLER
WEBVIEWCONROLLER:
CONTROLLER FOR DIFFERENT WEB VIEWS
LISTVIEWCONTROLLER:
DATA PROVIDER
Actually what happens is when i shake i reload the table view data and i add an object to an array (array of favorites) the count is one.... GOOD! But then when i shake again (in a different article, my app has different webViews when i press different cells.) It is still 1... weird.... if i go to favorites class that array remains one.. ok... so as you can see i am returning the arrayOfFavourites count to numberOfRowsInSection (which is 1) but no cells appear and the cellForRowAtIndexPath is never called (using an NSLOG) why is this happening I AM VERY ANNOYED!
In your Favourites.m numberOfRowsInSection function, looks like you should do this:
if(arrayOfFavourites == NULL)
{
arrayOfFavourites = [[NSMutableArray alloc] init];
}
Because you're reinitializing (and likely leaking) in every single call to numberOfRowsInSection (which gets called each time the table needs to know how many rows it must display -- i.e. very often).
You create and destroy a new Favourites object every time you go through -motionBegan:withEvent:, and you create a new array every time you go through -tableView:numberOfRowsInSection:. If you want data to persist beyond those events, you need to keep the objects around.
Let review this part of your code :
-(void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event {
cellToPassOn = nil;
NSLog(#"Favouriting"); // YES I KNOW SPELLING
// This is pretty simple, what we do is we take the cell we touched and take its title and link
// then put it inside an array in the Favourites class
// HERE you are creating a NEW fav
Favourites *fav = [[Favourites alloc] init];
// HERE you are creating a NEW list
ListViewController *list = [[ListViewController alloc] init];
// SO HERE what is "CELL" doing, returning some constant or static object?
[self setCellToPassOn: [list CELL]];
// HERE what is item and where does it come from
if (!item) {
NSLog(#"NILLED ITEM");
}
// Here you take an array of an object you just created and autoreleasing the item
// this is not the regular way to handle memory management in Cocoa,
// depending on what you are doing to item else where you could get item == deallocated pretty soon
[[fav arrayOfFavourites] addObject:[item autorelease]];
[fav setCell: cellToPassOn];
HERE you are releasing fav
[fav release];
HERE fav don't exist anymore as well as the array to which you've added something to it.
[list release];
item = nil;
}
Unless I'm reading your code incorrectly I have the feeling that you are trying to have some persistence with "volatile" object.
You need to make a #property for those object to survive longer that one method call.
Every time you create a new object it's new and have no knowledge of the precedent one.
And if we look at this code :
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// HERE everytime the tableview is asking for the numberOfRowsInSection, you create a new array
// And that new empty array is replacing your old one.
// That is your "weird" thing, it's doing what you are asking it to do, set it back to a new empty array.
arrayOfFavourites = [[NSMutableArray alloc] init];
NSLog(#"ROWS NO.");
NSLog(#"%i", [arrayOfFavourites count]);
return [arrayOfFavourites count];
}

TableView load rows from Web Service

I try to load rows from my web service into tableview object in iPhone project with xCode.
I use viewDidLoad method in order to load the items, in this method I call to my web service with this code:
eenAccesoCupon* Servicio = [[eenAccesoCupon alloc] init];
Servicio.logging=NO;
[Servicio GetCuponesEntrantes:self action:#selector(GetCuponesEntrantesHandler:) UsuarioActivo: 4];
I have a NSMutableArray (called listOfItems) that I use to load rows to TableView. If I add the items to this array into GetCuponesEntrantesHandler the tableview doesn't show any row. The sourceCode of this handler is the following:
(void) GetCuponesEntrantesHandler: (id) value {
// Handle errors
if([value isKindOfClass:[NSError class]]) {
NSLog(#"%#", value);
return;
}
// Handle faults
if([value isKindOfClass:[SoapFault class]]) {
NSLog(#"%#", value);
return;
}
// Do something with the NSMutableArray* result
NSMutableArray* listOfItems = (NSMutableArray*)value;
}
It seems that TableView rows are loaded before web method is called, therefore, tableview methods like numberOfRowsInSection and cellForRowAtIndexPath are called before the web services is invoked.If I load the items of rows in viewDidLoad like this way:
(void)viewDidLoad {
[super viewDidLoad];
//Initialize the array.
listOfItems = [[NSMutableArray alloc] init];
//Add items
[listOfItems addObject:#"Iceland"];
[listOfItems addObject:#"Greenland"];
[listOfItems addObject:#"Switzerland"];
[listOfItems addObject:#"Norway"];
[listOfItems addObject:#"New Zealand"];
[listOfItems addObject:#"Holland"];
[listOfItems addObject:#"Ireland"];
//Set the title
self.navigationItem.title = #"Countries";
eenAccesoCupon* Servicio = [[eenAccesoCupon alloc] init];
Servicio.logging=NO;
[Servicio GetCuponesEntrantes:self action:#selector(GetCuponesEntrantesHandler:) UsuarioActivo: 4];
}
In this case, tableview object shows only this 7 values load in listOfItems, never load any item from GetCuponesEntrantesHandler.
Somebody knows what is the problem?
I suppose that GetCuponesEntrantes: method works with the network asynchronously. This means that it will call the handler once the table view has already been loaded and displayed.
To force the table view to reload simply call:
[tableView reloadData]
at the end of the handler method, immediately after NSMutableArray* listOfItems = (NSMutableArray*)value; assignment.

UITableView with JSON help

I am trying to feed in some JSON data to my iPhone app, the data is coming in fine as I have NSLog's telling me so.
The problem I am having is trying to get the results to show in a UITableView. I have a navigation controller underneath a tab bar controller, the navigation controller contains a table view controller which loads another NIB file with a table view connected to a class which is the delegate and data source delegate.
I also need to categorize the results into sections - these being
England
Scotland
Wales
N.Ireland
To get an idea of what JSON string I am using see this one.
As you can see the JSON does not cater for the sections but I am yet to implement this, so i would need to know beforehand so I do not have to amend much code later on.
OK - I am using Stig JSON parser.
Here is my ListVenuesView.h (connected to table view)
#import <UIKit/UIKit.h>
#import "SBJson.h"
#interface ListVenuesView : UITableViewController <UITableViewDelegate, UITableViewDataSource> {
IBOutlet UITableView *venueList;
NSMutableDictionary *jsonArray;
}
#property (nonatomic, retain) IBOutlet UITableView *venueList;
#property (nonatomic, retain) NSMutableDictionary *jsonArray;
#end
jsonArray is used to store the JSON data and eventually the proper array.
And here is my ListVenuesView.m (key areas in question)
- (void)viewDidLoad
{
[super viewDidLoad];
NSLog(#"Table View Loaded");
// Uncomment the following line to preserve selection between presentations.
// self.clearsSelectionOnViewWillAppear = NO;
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem;
// This is where we load the JSON data
NSURL *jsonURL = [NSURL URLWithString:#"http://www.thebigfishexperience.org.uk/sources/ajax/venue-json.php?location=peterborough"];
NSString *jsonData = [[NSString alloc] initWithContentsOfURL:jsonURL];
NSLog(#"%#", jsonData);
// Convert jsonData to array
self.jsonArray = [jsonData JSONValue];
NSLog(#"%#", jsonArray);
NSLog(#"count is: %i", [self.jsonArray count]);
// Release NSString and NSURL
[jsonURL release];
[jsonData release];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
// Return the number of rows in the section.
return [self.jsonArray count];
}
- (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] autorelease];
}
NSMutableDictionary *dict = [self.jsonArray objectAtIndex: indexPath.row];
cell.textLabel.font = [UIFont fontWithName:#"Arial" size:15.0];
cell.textLabel.text = [dict objectForKey:#"venueName"];
cell.detailTextLabel.text = [dict objectForKey:#"venueCordDist"];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
// Configure the cell...
return cell;
Also how can I use the data in the cells to go to another subview of the nav controller which gives me a back button and displays the info from the JSON string just for that particular cell that has been tapped.
I think this has something to do with it? Not sure though as this is my first app i am building! So probably expect more pleas of assistance - ha ! ;)
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// Navigation logic may go here. Create and push another view controller.
/*
DetailViewController *detailViewController = [[DetailViewController alloc] initWithNibName:#"Nib name" bundle:nil];
// ...
// Pass the selected object to the new view controller.
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
*/
}
On selecting a row, as mentioned by u, we are navigating to another view. Let us assume that the view controller is DetailViewController which is a sub-class of UIViewController.
In the DetailViewController.h , declare a NSDictionary object.
In DetailViewController.m, add
-(void)setVenueDict:(NSDictionary*)venueDict
{
if( _venueDict )
{
[_venueDict release];
}
_venueDict = [venueDict retain];
}
In ParentViewController, ur didSelectRow.. method should be like this.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
// Navigation logic may go here. Create and push another view controller.
DetailViewController *detailViewController = [[DetailViewController alloc] initWithNibName:#"Nib name" bundle:nil];
// ...
// Pass the selected object to the new view controller.
NSDictionary *dict = [self.jsonArray objectAtIndex: indexPath.row];
[detailViewController setVenueDict:dict];
detailViewController.title = [dict objectForKey:#"venueName"];
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
}
In the second view controller, u can do whatever u want with the _venueDict.
Nathan,
since you want to reuse the data parsed from the JSON feed over more than one ViewController the best way to approach this is to build an object Model so that you can pass the object for the selected row in the list to the detail ViewController.
I would also separate the JSON parsing code into a separate class and not keep it in the ViewController.
You can find classes to fetch JSON on this link.
The result from the custom code to parse the JSON feed would give back a NSDictionary with as keys the section names you mention. And the value in the NSDictionary for those keys would be an array of your custom objects that contain all the relevant data for one row (and detail screen).
Hope this helps you on your way.
jsonArray is NSMutableDictionary.
have to use
[jsonArray objectForKey:key];
//check this line
NSMutableDictionary *dict = [self.jsonArray objectAtIndex: indexPath.row];
this may help.