Sorting array of custom objects into sections dynamically UITableview - uitableview

Question

I have a problem that's being plaguing me for a few days now.
I have an array called countries. This array contains a custom object which holds data such as Country, City, ip, status etc.
I need to present these objects in a tableview sectioned by the property "country".
This means that if I have two custom objects both with the country "Australia" I need to add it to a section called "Australia" and if I have 5 objects with the country "Spain" I need those 5 objects to be in the Spain section.
I need to find a way to make sure that even if an object is added with a different country it goes under a section with it's country name country name.
I've tried a variety of things but nothing has come even close to fixing this.
The reason why this is dynamic is because I don't know how many objects are going to be in each section. This means the number of objects in each section can change.
I used this code to sort the array alphabetically I just need to put each object into a section based on the property "Country" I do not know how many sections there will be or how many objects will be in each section.
self.countries = self.countries.sorted { $0.country < $1.country }
Could anyone give me a hand?
edit: added my cellForRowAtIndexPath.
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
if recievedData == true {
var cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! CountryListCell
var serverInfo = countries[indexPath.row] as ServerInfoObject
cell.countryTitle.text = serverInfo.country
cell.flagImage.image = UIImage(named: serverInfo.flag)
cell.serverInfo = serverInfo
return cell
}
return CountryListCell()
}

Answer 1

So you need to sort you servers into a dictionary. E.G [String:[Server]] the string being the section name (country). So an example dict ["Albania":[serv1,server2,...]]
You can simply do this by sorting through the server array (I assume you can figure this out).
You will also need to save an array of your section titles so that you can access it in cellForRowAtIndexPath. For example ["Albania","Brazil","Cuba","Germany","Russia"]
So basically when in cellForRowAtIndexPath you access the current country with
var country = yourSectionArray[indexPath.section]
Then access the array of servers that are valid to that country through your dictionary like so:
var serversOfCurrentSection = yourDictionary[country] as [Server]
Then to get the current server for the index just do
var server = serversOfCurrentSection[indexPath.row]
To get the number of objects in each section:
var country = yourSectionArray[indexPath.section]
yourDictionary[country].count

Answer 2

Did you try to use NSPredicate to help you filter your array by country name? I think you can either split your servers into an array of array on the run or at the beginning of load, depending on whether the list updates.
In numberOfRowsInSection:, just count the rows of the sub array at index section.
Similarly, in cellForRowAtIndexPath:, use your sorted arrays to get info from your custom class.
I had to deal with something similar with sorting contacts. Hopefully this helps!

Answer 3

There are lots of ways to do this.
Table views need stable data in order to work. If you change your data model, you need to tell your table view to reload.
I'd probably store the records 2 ways: In a flat array, and then in an array by countries where each entry in that array was an array of the records for that country. Collection objects like arrays save the objects inside them by reference, so there's not a lot of overhead in storing the same records in multiple arrays.
That makes creating your sectioned table view very clean.
You could sort your flat array of record by country, and then do a pass through the sorted array, building your arrays of records by country. If you need your records sorted by some other criteria within a country you might want to use an NSPredicate to do the sorting rather than sorted, since it can take an array of sort keys.
If the user can enter a new record at any spot, you could collect the data for that new record, then find the spot where it belongs in the sorted array, insert it at that spot, and then rebuild your 2 dimensional array of arrays from the sorted flat array. That would avoid re-sorting the entire array, which can be slow for large arrays of data.)