cell.imageview.image problem

CanDev · October 2011

I am loading a table with images. I am populating that table with a plist for information, and images, etc.

The problem I am having is that the cells that dont have an image assigned, are showing up with one anyway. The code I am using is this

 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @\"Cell\";
    
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
            // init with style indicates cell style
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
    }
   //adding image to cell
    NSString *path = [[NSBundle mainBundle] pathForResource:[dictionary objectForKey:@\"imageKey\"] ofType:@\"png\"];
    UIImage *theImage = [UIImage imageWithContentsOfFile:path];
    NSLog(@\"key: %@\", [dictionary objectForKey:@\"imageKey\"]);
cell.imageView.image = theImage;
    NSLog(@\"image: %@\", theImage);
    return cell;
}

So in my plist, I have only used the key "imageKey" in some of the entries, however, I am getting an image in all my cells

BrianSlick · October 2011

I'm going to guess that you're still getting a path. Log that and see what happens.

objch · October 2011

Also, the way you have it right now, every cell is getting the same image every time.

If you want to have different images in different cells, you need to make use of the indexPath argument of tableView:cellForRowAtIndexPath: and relate that to the contents of your property list.

CanDev · October 2011

the way i have it now, i get the correct (different) images for cells that i put a value in for the key "imageKey".

Yes I do get a path when logged and an image for each cell, but the key returns (null) for those that dont have a key ... which is correct.

So I want to have an image show up for only those cells that I assign a value to the key

BrianSlick · October 2011

You're getting a path, so presumably you're always getting an image, so you're never clearing out the image view. Change that.

CanDev · October 2011

BrianSlick;381287 said:
You're getting a path, so presumably you're always getting an image, so you're never clearing out the image view. Change that.

how do i do that?

BrianSlick · October 2011

cell.imageView.image = nil;

CanDev · October 2011

BrianSlick;381290 said:
cell.imageView.image = nil;

ok but where do I put that

BrianSlick · October 2011

Are you a programmer or not? Make some decisions. Use some programming logic. When do you want an image? When do you NOT want an image?

CanDev · October 2011

BrianSlick;381292 said:
Are you a programmer or not? Make some decisions. Use some programming logic. When do you want an image? When do you NOT want an image?

isnt that the whole point of the list. To place images where you indicate a key and the parts of the list that dont have an associated key with that value should get the image.

BrianSlick · October 2011

But we've already established that you get a path every time, so your logic is flawed.

CanDev · October 2011

BrianSlick;381297 said:
But we've already established that you get a path every time, so your logic is flawed.

exactly, and i dont know how to fix that. Thats why i ask the people who know these things. It would seem logical to me that when the program looks through the plist, it would only place an image in the table where the key would indicate and if there were no key in that dictionary then no image would be available to be shown. So I dont know where its getting the path from when that key doesnt exist.

BrianSlick · October 2011

You keep missing my point. Which part of the code - given that we have proven you get a path every time - leads you to believe that you would ever NOT get an image? What are you doing to prevent there from being an image shown?

CanDev · October 2011

BrianSlick;381302 said:
You keep missing my point. Which part of the code - given that we have proven you get a path every time - leads you to believe that you would ever NOT get an image? What are you doing to prevent there from being an image shown?

Should this

NSString *path = [[NSBundle mainBundle] pathForResource:[dictionary objectForKey:@\"imageKey\"] ofType:@\"png\"];

not limit the responses and only return a path for those items with the key "imageKey". What I dont understand and obviously what I am missing is, why do I get a path returned everytime even though there is no key with that name.

My top layer of my table has an image for each table entry, then as I drill down, some of the sub catagories do not have images assigned (ie. No key, or no value for the key "imageKey"

example snippet of my plist

					<dict>
							<key>imageKey</key>
							<string>Ukraine</string>
							<key>Title</key>
							<string>Ukraine</string>
						</dict>
						<dict>
							<key>imageKey</key>
							<string>United-Kingdom</string>
							<key>Title</key>
							<string>United Kingdom</string>
						</dict>
						<dict>
							<key>imageKey</key>
							<string>Vatican-City</string>
							<key>Title</key>
							<string>Vatican City</string>
						</dict>
					</array>
					<key>Title</key>
					<string>Europe</string>
				</dict>
				<dict>
					<key>Children</key>
					<array>
						<dict>
							<key>Title</key>
							<string>Afghanistan</string>
						</dict>
						<dict>
							<key>Title</key>
							<string>Bahrain</string>
						</dict>
						<dict>
							<key>Title</key>
							<string>Bangladesh</string>
						</dict>
						<dict>
							<key>Title</key>
							<string>Bhutan</string>
						</dict>
						<dict>
							<key>Title</key>
							<string>Brunei</string>
						</dict>
						<dict>
							<key>Title</key>
							<string>Burma</string>
						</dict>
						<dict>
							<key>Title</key>
							<string>Cambodia</string>
						</dict>
						<dict>
							<key>Title</key>
							<string>China</string>
						</dict>

but every single row of every level has an image and thats what i dont understand

BrianSlick · October 2011

As objch suggested, why would the value for "dictionary" ever be different?

CanDev · October 2011

BrianSlick;381305 said:
As objch suggested, why would the value for "dictionary" ever be different?

because its the value of "imageKey" that is different (or not there at all). Where I do have values for it, I get different images for each cell as expected.

BrianSlick · October 2011

No no, the dictionary itself. Why would the dictionary ever be different? Is there some code that you aren't showing here? Because if that is the complete cellForRow above, then dictionary will be the same for every single row.

CanDev · October 2011

BrianSlick;381307 said:
No no, the dictionary itself. Why would the dictionary ever be different? Is there some code that you aren't showing here? Because if that is the complete cellForRow above, then dictionary will be the same for every single row.

This is my cellForRowAtIndexPath

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @\"Cell\";
    
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
            // init with style indicates cell style
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
    }
    
        // Set up the cell...
    NSDictionary *dictionary = [self.competingBands objectAtIndex:indexPath.row];
        // adding arrow to right side of cell
    cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
        // main cell text
    cell.textLabel.text = [dictionary objectForKey:@\"Title\"];
        //use if you want to change text color for every other row
    UIColor *color = ((indexPath.row % 2) == 0) ? [UIColor colorWithRed:0/255 green:0/255 blue:0/255 alpha:1] : [UIColor blackColor];
    cell.textLabel.textColor = color;
        // subtitle cell text
    cell.detailTextLabel.text = [dictionary objectForKey:@\"Description\"];
    cell.detailTextLabel.textColor = [UIColor blackColor];
    cell.detailTextLabel.textAlignment = UITextAlignmentLeft;
        //adding image to cell
    NSString *path = [[NSBundle mainBundle] pathForResource:[dictionary objectForKey:@\"imageKey\"] ofType:@\"png\"];
    NSLog(@\"Path: %@\", path);
    UIImage *theImage = [UIImage imageWithContentsOfFile:path];
    NSLog(@\"key: %@\", [dictionary objectForKey:@\"imageKey\"]);
        // to make rounded edges on square corners
        //cell.imageView.layer.masksToBounds = YES;
        //cell.imageView.layer.cornerRadius = 5.0;
    
    cell.imageView.image = theImage;
    NSLog(@\"image: %@\", theImage);
    return cell;
}

and didSelectRow is as follows

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
        //Get the dictionary of the selected data source.
    NSDictionary *dictionary = [self.competingBands objectAtIndex:indexPath.row];

    //Get the children of the present item.
    NSArray *Children = [dictionary objectForKey:@\"Children\"];
    
    if([Children count] == 0) {
        DetailViewController *dvController = [[DetailViewController alloc] initWithNibName:@\"DetailView\" bundle:[NSBundle mainBundle]];
		[self.navigationController pushViewController:dvController animated:YES];
		[dvController release];
        
    }
    else {
        NSLog(@\"Entering %s\", __PRETTY_FUNCTION__);
            //Prepare to tableview.
        BandListViewController *BLVController = [[BandListViewController alloc] initWithNibName:@\"BandList\" bundle:[NSBundle mainBundle]];
        
            //Increment the Current View
        BLVController.CurrentLevel += 1;
        NSLog(@\"Implement current View\");
            //Set the title;
        BLVController.CurrentTitle = [dictionary objectForKey:@\"Title\"];
        
            //Push the new table view on the stack
        [self.navigationController pushViewController:BLVController animated:YES];
        NSLog(@\"New view pushed onto stack\");
        BLVController.competingBands = Children;
        
        [BLVController release];
    }
    
}

WChambers · October 2011

Try something along these lines(will probably need some tweaks):


 NSString *Image = [[NSBundle mainBundle] pathForResource:[dictionary objectForKey:@\"imageKey\"];
    Image = [Image stringByAppendingFormat:@\".png\"];
    cell.imageView.image = [UIImage imageNamed:Image];

This is assuming your .png file has the same name as your value for Key. ie : imageKey = Russia, and the png is Russia.png (not RussiaImage.png).

Hope this helps/provides some insight.

CanDev · October 2011

WChambers;381312 said:
Try something along these lines(will probably need some tweaks):
 NSString *Image = [[NSBundle mainBundle] pathForResource:[dictionary objectForKey:@\"imageKey\"];
    Image = [Image stringByAppendingFormat:@\".png\"];
    cell.imageView.image = [UIImage imageNamed:Image];
This is assuming your .png file has the same name as your value for Key. ie : imageKey = Russia, and the png is Russia.png (not RussiaImage.png).

Hope this helps/provides some insight.

Sorry that didnt work, just ended up crashing. Will keep working on it and post here when I have a solution

WChambers · October 2011

I'm not very experienced, so take my advice with a grain or two of salt.

I think the issue may have something to do with the lack of imageKey on some of the dictionaries. If its returning "null" ofType "png", is it assigning the first available png file from your resources? Do you have an image set manually in IB, such that when it gets null, it just has the one initially assigned?

Just throwing stuff out there to ponder. I have a new found hatred for images on cells from my own app experience these last 2 days.

BrianSlick · October 2011

Ah yes, when posting code, it's always useful to neglect to point out that not everything is included. That makes troubleshooting so much easier.

So in the rows that are not supposed to have images, what images do they wind up getting? Are they the same every time, or different?

And the bottom line is this: you're expecting the path to be nil in that case. That isn't happening, so you need to try something else. You've already stated two or three times what the criteria is, so I really don't understand why you're having so much trouble thinking of something to try.

CanDev · October 2011

BrianSlick;381316 said:
Ah yes, when posting code, it's always useful to neglect to point out that not everything is included. That makes troubleshooting so much easier.

So in the rows that are not supposed to have images, what images do they wind up getting? Are they the same every time, or different?

And the bottom line is this: you're expecting the path to be nil in that case. That isn't happening, so you need to try something else. You've already stated two or three times what the criteria is, so I really don't understand why you're having so much trouble thinking of something to try.

The rows that are not supposed to have images, have the first image alphabetically that i have in my images folder. So is there a way to have a key return nil instead of null. Obviously on a null return, it defaults to my first image, which I dont want.

My images are all set programatically, not thru IB

BrianSlick · October 2011

You're not thinking this through at all. The problem is not with the key, the problem is with the path sniffer. objectForKey already does return nil if the key isn't there. SO TEST FOR THE PRESENCE OF THE KEY. Jesus. If you want A to happen in one situation, but B to happen in another, write a freaking test. if A else B. This is Programming Logic 101 here.

CanDev · October 2011

BrianSlick;381352 said:
You're not thinking this through at all. The problem is not with the key, the problem is with the path sniffer. objectForKey already does return nil if the key isn't there. SO TEST FOR THE PRESENCE OF THE KEY. Jesus. If you want A to happen in one situation, but B to happen in another, write a freaking test. if A else B. This is Programming Logic 101 here.

Well first off, I never once said i was a programmer. This is all new to me and I am trying to do the best I can, and thats why i am asking questions on this forum. I didnt know this forum was for the experienced programmers. Anyway, if the key isnt there, its returning null, according to the NSLog, but I guess i dont know enough about that to be sure. So I will figure out an if statement to work if there is no key for my object for that particular part of my table.

Sorry to waste your time Brian, good day to you :) Off to read more of the documentation that isnt always as clear as I would like.

And While i am at it, I did read your series on tablesview, very good! very informative, waiting for the rest :)

BrianSlick · October 2011

No, it is printing null, it is returning nil. So your test will be:

if ([dictionary objectForKey:theKey] == nil)

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