iOS Populate a view from an array

[PlutoM4]

Hi all! I would ask for your help. I'm developing an app that has:

A. Item.h

@interface Items : NSObject
 
@property (nonatomic, strong) NSString *categoryName; // category's name
@property (nonatomic, strong) NSString *categoryImage; // image showed on the left of the table row
@property (nonatomic, strong) NSString *tipTextField; // text displayed in a single tip

B. MainTableViewController.m

#import "Items.h"
 
#import "CategoryTableViewCell.h"
 
{
    NSArray *categoryArray;
 
    NSArray *tipsArray;
}
 
// Initialize items of category1
    Items *tip1 = [Items new];
    tip1.tipTextField = @"text goes here";
 
//Create tips array
 
    tipsArray = [NSArray arrayWithObjects: tip1, tip2, ..., nil];
 
// Initialize the category array
    Items *category1 = [Items new];
    category1.categoryName = @"Category1";
    category1.categoryImage = @"image.png";
    category1.tipTextField = tipsArray [0];
    
 

//ADDED TEXT AFTER EDITING POST
categoryArray = [NSArray arrayWithObjects: category1, category2, category3, category4, category5, category6, category7, category8, nil];

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    if (tableView == self.searchDisplayController.searchResultsTableView) {
        return [searchResults count];
        
    } else {
        return [categoryArray count];
    }
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"CustomTableCell";
    CategoryTableViewCell *cell = (CategoryTableViewCell *)[self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    
    // Configure the cell...
    if (cell == nil) {
        cell = [[CategoryTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    }
    
    // Display category in the table cell
    Items *item = nil;
    if (tableView == self.searchDisplayController.searchResultsTableView) {
        item = [searchResults objectAtIndex:indexPath.row];
    } else {
        
        item = [categoryArray objectAtIndex:indexPath.row];
    }
    
    cell.nameLabel.text = item.categoryName;
    cell.thumbnailImageView.image = [UIImage imageNamed:item.categoryImage];
    
    return cell;
}

//Set row height at 52
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return 52;
}

//View details of selected category
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([segue.identifier isEqualToString:@"showTipDetail"]) {
        NSIndexPath *indexPath = nil;
        Items *item = nil;
        
        if (self.searchDisplayController.active) {
            indexPath = [self.searchDisplayController.searchResultsTableView indexPathForSelectedRow];
            item = [searchResults objectAtIndex:indexPath.row];
        } else {
            indexPath = [self.tableView indexPathForSelectedRow];
            item = [categoryArray objectAtIndex:indexPath.row];
            
        }
        
        CategoryDetailsViewController  *destViewController = segue.destinationViewController;
        destViewController.item = item;
    }
}

Simply I want that a CategoryDetailsViewController shows tipTextField. So, in CategoryDetailsViewController.h I set:

#import "Items.h"
 
@property (weak, nonatomic) IBOutlet UITextView *tipTextField;
 
@property (nonatomic, strong) Items *item;

and in CategoryDetailsViewController.m:

- (void)viewDidLoad
{
    [super viewDidLoad];
       
    tipTextField.text = self.item.tipTextField;

but when from a row I want to see detailed text of category (i.e. tip1 for Category1) my app crashes for [super viewDidLoad], with [NSObject(NSObject) doesNotRecognizeSelector:]:

I would achieve that user taps on a row (that is a category) and a DetailsViewController appears. Here, with "previous" and "forward" buttons he can navigate through items for each category.

Any help? Feel free to ask for more code if needed, thanks in advance!

 

[DannyBres]

Quite confusing, seems a strange data model.

From your code. you create an NSArray of Items (which has instance variables of categoryName, categoryImage, tipTextField) with only their tipTextField populated called tipsArray.

You then create a new item called category1 set the other instance variables categoryName and categoryImage and then try and set the tipTextField instance variable of category1 to tipsArray [0];, you cannot do this as tipsArray [0] returns an instance of Items not an NSString.

Why have you set your model up like this? does an item have an image a category and tiptextfield?

 

[PlutoM4]

Quite confusing, seems a strange data model.

From your code. you create an NSArray of Items (which has instance variables of categoryName, categoryImage, tipTextField) with only their tipTextField populated called tipsArray.

You then create a new item called category1 set the other instance variables categoryName and categoryImage and then try and set the tipTextField instance variable of category1 to tipsArray [0];, you cannot do this as tipsArray [0] returns an instance of Items not an NSString.

Why have you set your model up like this? does an item have an image a category and tiptextfield?

Hi Danny, thanks for your help.

This data model originate from a mix of tutorial, q&a and Obj-C studying.

I agree with you, it's so confusing but take it as my sandbox to test and learn.

I will study your answer and I ask for an alternative approach to question, that is:

1. several categories with name and an image for TableView;
2. several text items for each category, being displayed one-by-one in a CategoryDetailsView's text field;
3. two button (Previous and next) to navigate among items of each category.

Thanks again!

 

[DannyBres]

Need to think of a scheme.

Sounds like you have

Category
NSString *Name
NSImage *Image (might be best not to sort the images in here, bad memory management practice, only load when needed)
NSArray *tips

 

[PlutoM4]

Need to think of a scheme.

Sounds like you have

Category
NSString *Name
NSImage *Image (might be best not to sort the images in here, bad memory management practice, only load when needed)
NSArray *tips

I have just updated code of MainTableViewController.m, hope this help.

I'm becoming so confused, I hope to figure out..

 

[DannyBres]

How are you learning? From your Item object, i am concern you have not quite grasp some of the OOP concepts.

 

[PlutoM4]

How are you learning? From your Item object, i am concern you have not quite grasp some of the OOP concepts.

You're right, I'm a newbie and I'm studying from tutorial and from a book called "Programming in Objective C".

I study in my spare time and from few days, so it's possible I haven't still some fundamentals.

Thanks anyway for your time and for answers, I will try to study harder.

 

[DannyBres]

ok, pm me if you need more help.