How sort objects parsed from XML..

Question

so I want to parse an xml and display (in a UITableView) the "subjects" in ascending order depending on "lessons"

XML:

<parfumeo_kkn>
<tt_timetable>
    <id>1015</id>
    <day>1</day>
    <class_id>98</class_id>
    <lesson>9</lesson>
    <teacher>bt</teacher>
    <room>V1.2</room>
    <subject>M</subject>
    <pr_id>54</pr_id>
</tt_timetable>
<tt_timetable>
    <id>1014</id>
    <day>1</day>
    <class_id>98</class_id>
    <lesson>8</lesson>
    <teacher>bt</teacher>
    <room>V1.2</room>
    <subject>bg</subject>
    <pr_id>54</pr_id>
</tt_timetable>

ect.

(In this little example there would be "bg" before "M".) I allready set up my parser but it's not working in the order I want it to. thx for help

Answer 1

You should separate the logic of the parser and how you display the results in the table views. The parser just does its task of parsing the xml, the controller for the table view will do a little bit extra task by ordering the results from the parser by using NSSortDescriptor, an example follows:

    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"lesson" ascending:YES];
    NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];

    [fetchRequest setSortDescriptors:sortDescriptors];

Yes, previously I am assuming you're using Core Data, in case you just have a normal array, then you can just simply call:

    NSArray *myArray = [xmlResultArray sortedArrayUsingDescriptors:sortDescriptors];

Now you can use myArray to populate to your table view controller.

Hope this helps!

Answer 2

Maybe, you can parse you XML file, put objects in a array then sort this array ?

NSArray *myArray = [parser parseTheFile:file];
[self sortTheArray:myArray];

Answer 3

To sort an array you just do this.

NSArray *sortedPairs = [originalArray sortedArrayUsingSelector:@selector(compare:)];

If you have a dictionary and want to get a sorted array by keys you'd

NSArray *arr = [dictionary keysSortedByValueUsingSelector:@selector(compare:)];

once you have your array you can enumerate as you wish.