unable to handover a string to my method - xcode

Question

I have a problem in getting a method to work, and I am totally confused.
I am unable to hand over a string as a variable for my method.
I call the function even with the string, no variable currently.
Engine *myEngine = [Engine sharedInstance];
[myEngine getContentArrayFromEngine:#"zumbra"];
My method
-(NSMutableArray*) getContentArrayFromEngine:(NSString *)catName{
NSMutableSet* categorieContent = [[NSMutableSet alloc] init];
NSLog(#"Catname:%#", catName);
//some more code
}
NSLOG output
2011-12-18 18:49:44.165 Zitate[77224:15203] Catname:(null)
Why is catName empty ???
edit1: the complete code
ThirdViewController.m
-(void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
NSString* myTempCatname;
myTempCatname = cell.textLabel.text;
// NSLog(#"test select %#", myTempCatname);
DetailViewController *detailVC = [self.storyboard instantiateViewControllerWithIdentifier:#"detailzitat"];
[self.navigationController pushViewController:detailVC animated:YES];
Engine *myEngine = [Engine sharedInstance];
[myEngine getContentArrayFromEngine:myTempCatname];
}
and in the engine.m
-(NSMutableArray*) getContentArrayFromEngine:(NSString *)catName{
NSMutableSet* categorieContent = [[NSMutableSet alloc] init];
NSLog(#"Übergebener Catname:%#", catName);
// catName=#"zumbra";
// NSLog(#"Inhalt InhalteFromWeb:%#", InhalteFromWeb);
NSLog(#"Catname:%#", catName);
unsigned count = [InhalteFromWeb count];
while (count--) {
NSLog(#"count %d %#", count, [[InhalteFromWeb objectAtIndex:count] objectForKey:CATEGORY]);
if([[[InhalteFromWeb objectAtIndex:count] objectForKey:CATEGORY] isEqualToString:catName]) {
[categorieContent addObject:[InhalteFromWeb objectAtIndex:count]];
NSLog(#"Row %d has Content%#",count, [InhalteFromWeb objectAtIndex:count]);
}
}
NSLog(#"Inhalt Category:%#", categorieContent);
NSArray* tempAr = [[NSArray alloc] initWithArray:[categorieContent allObjects]];
return [NSMutableArray arrayWithArray:tempAr];
}
EDIT2:
Ok, even the hint with the catName did not work. so I have changed my code a little bit.
I have an array with a category, title, content, author, image for each row
I would like to do two things
1) get a unique list of all categories (its working fine)
2) when tapping on one of these categories , open a detailView , show the first element of this category, jump to previous and next item in category by swiping around.
For this, I am going to SET the category I have chosen
First try was to handover in the method, which did not work.
Now I though, SET the category in my engine.h and when displaying the single item, get the array for this category back.
but again, the value of the category is not stored.
ThirdViewController.h
#import <UIKit/UIKit.h>
#import "SecondViewController.h"
#interface ThirdViewController : UIViewController<UITableViewDelegate, UITableViewDataSource> {
NSMutableArray* CategoryList;
}
#property (nonatomic, retain) NSMutableArray* CategoryList;
#end
ThirdViewController.m
#import "ThirdViewController.h"
#import "engine.h"
#import "DetailViewController.h"
#implementation ThirdViewController
#synthesize CategoryList;
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
Engine *myEngine = [Engine sharedInstance];
CategoryList = [myEngine getCategories];
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [CategoryList count];
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
static NSString *CellIdentifier =#"Cell";
UITableViewCell *cell = (UITableViewCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if(cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
cell.textLabel.text = [CategoryList objectAtIndex:indexPath.row];
return cell;
}
-(void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
NSString* myTempCatname;
myTempCatname = cell.textLabel.text;
DetailViewController *detailVC = [self.storyboard instantiateViewControllerWithIdentifier:#"detailzitat"];
[self.navigationController pushViewController:detailVC animated:YES];
Engine *myEngine = [Engine sharedInstance];
[myEngine setCategName:myTempCatname];
NSLog(#"Aufruf %#", myTempCatname);
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#end
DetailViewController.h
#import <UIKit/UIKit.h>
#import <MessageUI/MFMailComposeViewController.h>
#import "engine.h"
#interface DetailViewController : UIViewController<MFMailComposeViewControllerDelegate> {
IBOutlet UILabel *authorLabel;
IBOutlet UILabel *categoryLabel;
IBOutlet UILabel *titleLabel;
IBOutlet UITextView *contentTextView;
NSString *authorText, *contentText, *categoryText, *titleText, *imageText, *catName;
NSMutableArray *contentArray;
}
#property (nonatomic, retain) IBOutlet UITextView *contentTextView;
#property (nonatomic, retain) IBOutlet UILabel *authorLabel;
#property (nonatomic, retain) IBOutlet UILabel *categoryLabel;
#property (nonatomic, retain) IBOutlet UILabel *titleLabel;
#property (nonatomic, retain) NSString *authorText, *contentText, *categoryText, *titleText, *imageText, *catName;
#property (nonatomic, retain) NSMutableArray *contentArray;
-(IBAction)vorher:(id)sender;
-(IBAction)nachher:(id)sender;
#end
DetailViewController.m
#import "DetailViewController.h"
#implementation DetailViewController
#synthesize contentTextView;
#synthesize authorText, contentText, categoryText, titleText, imageText;
#synthesize authorLabel, categoryLabel, titleLabel;
#synthesize contentArray;
#synthesize catName;
int contentIndex;
int contentMax;
- (IBAction)swipeDetected:(UIGestureRecognizer *)sender {
NSLog(#"Right Swipe detected");
}
-(IBAction) vorher:(id)sender {
NSLog(#"-----VORHER Button gedrückt-------");
if (contentIndex==0) {contentIndex=contentMax-1;}
else {contentIndex--;}
titleText = [[contentArray objectAtIndex:contentIndex] objectForKey:TITLE];
authorText= [[contentArray objectAtIndex:contentIndex] objectForKey:AUTHOR];
contentText= [[contentArray objectAtIndex:contentIndex] objectForKey:CONTENT];
authorLabel.text=authorText;
titleLabel.text=titleText;
contentTextView.text=contentText;
}
-(IBAction) nachher:(id)sender {
NSLog(#"-----Nachher Button gedrückt-------");
if (contentIndex==contentMax-1) {contentIndex=0;}
else {contentIndex++;}
titleText = [[contentArray objectAtIndex:contentIndex] objectForKey:TITLE];
authorText= [[contentArray objectAtIndex:contentIndex] objectForKey:AUTHOR];
contentText= [[contentArray objectAtIndex:contentIndex] objectForKey:CONTENT];
authorLabel.text=authorText;
titleLabel.text=titleText;
contentTextView.text=contentText;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
Engine *myEngine = [Engine sharedInstance];
contentArray = [myEngine getContentArrayFromEngine];
contentMax = [contentArray count];
UISwipeGestureRecognizer *swipeRecognizerRight =
[[UISwipeGestureRecognizer alloc]
initWithTarget:self
action:#selector(vorher:)];
swipeRecognizerRight.direction = UISwipeGestureRecognizerDirectionRight;
[self.view addGestureRecognizer:swipeRecognizerRight];
UISwipeGestureRecognizer *swipeRecognizerLeft =
[[UISwipeGestureRecognizer alloc]
initWithTarget:self
action:#selector(nachher:)];
swipeRecognizerLeft.direction = UISwipeGestureRecognizerDirectionLeft;
[self.view addGestureRecognizer:swipeRecognizerLeft];
titleText = [[contentArray objectAtIndex:contentIndex] objectForKey:TITLE];
authorText= [[contentArray objectAtIndex:contentIndex] objectForKey:AUTHOR];
contentText= [[contentArray objectAtIndex:contentIndex] objectForKey:CONTENT];
authorLabel.text=authorText;
titleLabel.text=titleText;
contentTextView.text=contentText;
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#end
engine.h
//#import
#define AUTHOR #"author"
#define CATEGORY #"cat"
#define CONTENT #"content"
#define IMAGE #"image"
#define TITLE #"title"
#interface Engine : NSObject {
NSMutableArray* InhalteFromWeb;
NSInteger maxAnzahlInhalte;
NSString* categNameStorage;
}
+ (Engine *) sharedInstance;
- (NSMutableArray*) getZitateArrayFromEngine;
- (NSInteger) getMaxAnzahlZitateFromEngine;
- (NSString*) getAutor:(NSInteger)pos;
- (NSString*) getZitat:(NSInteger)pos;
- (NSString*) getAuthor:(NSInteger)pos;
- (NSString*) getCategory:(NSInteger)pos;
- (NSString*) getContent:(NSInteger)pos;
- (NSString*) getImage:(NSInteger)pos;
- (NSString*) getTitle:(NSInteger)pos;
-(NSMutableArray*) getContentArrayFromEngine;
-(void) setCategName:(NSString *) categNameVariable;
-(NSString*) getCategName;
-(NSMutableArray*) getCategories;
#end
engine.m
#import "Engine.h"
#implementation Engine
static Engine *_sharedInstance;
- (id) init
{
if (self = [super init])
{
// custom initialization
//Beginn my code
NSURL *url = [NSURL URLWithString:#"http://www.*/iMotivate.plist"];
NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:url];
NSURLConnection *theConnection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self];
if( theConnection )
{
InhalteFromWeb = [[NSMutableArray alloc] initWithContentsOfURL:url];
maxAnzahlInhalte = [InhalteFromWeb count];
}
else
{
NSLog(#"Connection failed");
}
}
return self;
}
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
// NSLog(#"Recieving Response...");
}
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
// NSLog(#"Recieving Data...");
}
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Error"
message : #"An error has occured.Please verify your internet connection."
delegate:nil
cancelButtonTitle :#"OK"
otherButtonTitles :nil];
[alert show];
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
// NSLog(#"DONE. Received Quotes: %d", maxAnzahlZitate);
}
// ###########
+ (Engine *) sharedInstance
{
if (!_sharedInstance)
{
_sharedInstance = [[Engine alloc] init];
}
return _sharedInstance;
}
// Getter and Setter for WebArray
- (NSMutableArray*) getZitateArrayFromEngine{
return InhalteFromWeb;
}
- (NSInteger) getMaxAnzahlZitateFromEngine{
return maxAnzahlInhalte;
}
- (NSString*) getAutor:(NSInteger)pos{
return [[InhalteFromWeb objectAtIndex:pos] objectForKey:AUTHOR];
}
- (NSString*) getZitat:(NSInteger)pos{
return [[InhalteFromWeb objectAtIndex:pos] objectForKey:CONTENT];
}
// #######
- (NSString*) getAuthor:(NSInteger)pos{
return [[InhalteFromWeb objectAtIndex:pos] objectForKey:AUTHOR];
}
- (NSString*) getCategory:(NSInteger)pos{
return [[InhalteFromWeb objectAtIndex:pos] objectForKey:CATEGORY];
}
- (NSString*) getContent:(NSInteger)pos{
return [[InhalteFromWeb objectAtIndex:pos] objectForKey:CONTENT];
}
- (NSString*) getImage:(NSInteger)pos{
return [[InhalteFromWeb objectAtIndex:pos] objectForKey:IMAGE];
}
- (NSString*) getTitle:(NSInteger)pos{
return [[InhalteFromWeb objectAtIndex:pos] objectForKey:TITLE];
}
-(NSArray*) getCategories {
NSMutableSet* categorieSet = [[NSMutableSet alloc] init];
unsigned count = [InhalteFromWeb count];
while (count--) {
NSString *tempString;
tempString=[[InhalteFromWeb objectAtIndex:count] objectForKey:CATEGORY];
// NSLog(#"tempString %#", tempString );
[categorieSet addObject:tempString];
}
// NSLog(#"categories from engine %#", categorieSet);
NSArray* tempAr = [[[NSArray alloc] initWithArray:[categorieSet allObjects]]sortedArrayUsingSelector:#selector(caseInsensitiveCompare:)];
return [NSMutableArray arrayWithArray:tempAr];
}
-(void) setCategName:(NSString *) categNameVariable
{ NSLog(#"categNameStorage 2%#",categNameStorage);
categNameStorage=categNameVariable;
NSLog(#"setCategName 1 %#",categNameVariable);
NSLog(#"categNameStorage 2%#",categNameStorage);
}
-(NSString*) getCategName {
return categNameStorage;
}
-(NSMutableArray*) getContentArrayFromEngine{
NSMutableSet* categorieContent = [[NSMutableSet alloc] init];
NSLog(#"Übergebener Catname:%#", categNameStorage);
// NSLog(#"Inhalt InhalteFromWeb:%#", InhalteFromWeb);
unsigned count = [InhalteFromWeb count];
while (count--) {
// NSLog(#"count %d %#", count, [[InhalteFromWeb objectAtIndex:count] objectForKey:CATEGORY]);
if([[[InhalteFromWeb objectAtIndex:count] objectForKey:CATEGORY] isEqualToString:categNameStorage]) {
[categorieContent addObject:[InhalteFromWeb objectAtIndex:count]];
// NSLog(#"Row %d has Content%#",count, [InhalteFromWeb objectAtIndex:count]);
}
}
// NSLog(#"Inhalt Category:%#", categorieContent);
NSArray* tempAr = [[NSArray alloc] initWithArray:[categorieContent allObjects]];
return [NSMutableArray arrayWithArray:tempAr];
}
#end

Answer 1

There has to be a variable conflict with 'catName' in your view controller. I'm not sure why the view controller would be in scope, but I bet if you change your parameter to "inCatName" it will be fine. It's good to use naming conventions like that for this reason.