Question

In my application i have a table view controller that builds a table with sections from a .plist file. Every cell is unique, as it’s based on ID parameter that is stored for every item in the plist file and cannot repeat. As example of the plist:

<dict>
<key>Section One</key>
<dict>
    <key>Item 0</key>
    <dict>
        <key>name</key>
        <string>Some name one</string>
        <key>picfile</key>
        <string>take8.png</string>
        <key>takeItemId</key>
        <integer>101</integer>
    </dict>
    <key>Item 1</key>
    <dict>
        ...
    </dict>
</dict>
<key>Section Two</key>
<dict>
    <key>Item 0</key>
    <dict>
        <key>name</key>
        <string>Some name two</string>
        <key>picfile</key>
        <string>take6.png</string>
        <key>takeItemId</key>
        <integer>103</integer>
    </dict>
    <key>Item 1</key>....

So my table consists of cells containing a text label (takeItemID), a picture from file and another text label (Name).
Now, i have some event that brings an ID as a string (I receive commands from tcp socket connection). And I want my table to highlight (to change a background) in those cells that contain received ID string as the corresponding text label. Getting NSIndexPath somehow from the plist would be OK as well.

Edit: here below is my TableView:cellForRowAtIndexPath:

 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
    {    
NSUInteger section = [indexPath section];
NSUInteger row = [indexPath row];

NSString *sGroup = [sequencerGroups objectAtIndex:section]; 
NSDictionary *tSection = [sequencer objectForKey:sGroup];  

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"SecuencerCell"];

NSString *takeItemName = [[[tSection allKeys] sortedArrayUsingSelector:@selector(compare:)] objectAtIndex:row]; 
NSDictionary *takeItem = [tSection objectForKey:takeItemName]; 

UILabel *idLabel = (UILabel *)[cell viewWithTag:104];
idLabel.text = [NSString stringWithFormat:@"%@",[takeItem valueForKey:@"takeItemId"]];

UILabel *nameLabel = (UILabel *)[cell viewWithTag:102];
nameLabel.text = [takeItem valueForKey:@"name"]; 

UIButton *piconButton = (UIButton *)[cell viewWithTag:101];
UIImage *TakeImage = [UIImage imageNamed:[takeItem valueForKey:@"picfile"]];
[piconButton setBackgroundImage:TakeImage forState:UIControlStateNormal];


UIButton *resumeButton = (UIButton *)[cell viewWithTag:103];    
UIImage *resumeImage = [UIImage imageNamed:@"resume.png"];
[resumeButton setBackgroundImage:resumeImage forState:UIControlStateNormal];



return cell;   
 }

Edit: here is where sequencerGroups and sequencer are taken from:

NSString *path = [documentsDirectory stringByAppendingPathComponent:@"Sequencer.plist"];

NSDictionary *dict = [[NSDictionary alloc] initWithContentsOfFile:path];
self.sequencer = dict; 
[dict release];

NSArray *array = [sequencer allKeys];

self.sequencerGroups = array;

Thanks a lot,
Maxim

Answer 1

To create an indexPath from a rowNumber you can use: [NSIndexPath indexPathForRow:<#(NSInteger)#> inSection:<#(NSInteger)#>];

This makes row->indexPath conversion easy, once you have the row & section numbers.

So your question then becomes – how do I get the row & section numbers from the takeItemId.

I think the way I would approach it (there are numerous ways you can consider however, depending on how critical the execution time of loading your plist is) would be – right after I parse the plist, I would construct an NSDictionary which maps the takeItemId to an IndexPath.

An example:

NSDictionary *myPlist = ...
NSMutableDictionary *mapKeyToIndexPath = [NSMutableDictionary dictionary];
NSUInteger section = 0;
NSUInteger row = 0;
for (id sectionKey in [myPlist allKeys]) {
    // Parse Sections First
    NSDictionary *section = [myPlist objectForKey:sectionKey];
    for (id rowKey in [section allKeys]) {
        // Parse Rows Next
        NSDictionary *row = [section objectForKey:rowKey];
        NSString *takeItemId = [row objectForKey:@"takeItemId"];

        NSIndexPath *indexPath = [NSIndexPath indexPathForRow:row++ inSection:section];
        [mapKeyToIndexPath addObject:indexPath forKey:takeItemId];
    }
    // Move to first row, next section
    row = 0;
    section ++;
}

Once you have the mapKeyToIndexPath dictionary, you can then grab the correct indexPath when you receive the takeItemId in your Event and pass it to [myTableDataSource tableView:myTableView highlightCellAtIndexPath:indexPath];