xcode - How to load images from xml the right way?

Question

I'm quite new to xcode na objective-c so I'm sorry for the dumb question. What I want to do is to load images to cells in UITableView according to id. Every object in xml has the id and the image name id id.jpg. I accomplished to load them right but when I scroll the images dissapear. From what I have found it looks like it has something to do with dequeueReusableCellWithIdentifier but I can't figure out what is it. Here is the code I'm using to load the images:

-(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];
    }

    theList = [app.listArray objectAtIndex:indexPath.row];

    NSString *trimmedString = [theList.t_image stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];

    cell.imageView.image = [UIImage imageNamed:trimmedString];
    cell.textLabel.text = theList.t_name;
    cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;

    if(cell.imageView.image == nil){
        cell.imageView.image = [UIImage imageNamed:@"untitled.jpg"];
    }

    return cell;
}

and here is the xml:

<taxis>
<taxi>
<t_id>1</t_id>
<t_image>1.jpg</t_image>
<t_name>AAA Taxi</t_name>
<t_tel>+42014014</t_tel>
<t_addr>Vodičkova 40</t_addr>
<t_web>www.radiotaxiaaa.cz</t_web>
<t_getin>40</t_getin>
<t_km>26.9</t_km>
<t_wait>5</t_wait>
<t_city>Praha</t_city>
</taxi>
<taxi>
<t_id>2</t_id>
<t_image>2.jpg</t_image>
<t_name>Modrý anděl</t_name>
<t_tel>+420737222333</t_tel>
<t_addr>Cukrovarská 33</t_addr>
<t_web>www.modryandel.cz</t_web>
<t_getin>40</t_getin>
<t_km>19</t_km>
<t_wait>6</t_wait>
<t_city>Praha</t_city>
</taxi>
</taxis>

Thanks for any answer.

Answer 1

do all rows have picture? if not make sure to set cell.imageView to nil at the beginnign of the method after

if(cell == nil){
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
}

UPDATE : If i were you i would cache the images in an array and load them from this array in cellforrowatindexpath method.Try this i will probably work.Note that you can not add nil as object to NSmutablearray so you need to add another value rather than nil and UIimage