Sorting data.

[fx.barrett]

I need a bit of help/advice on the following problem:

1) I have a FileSystemDataGrid that has 3 columns, each column having custom labelFunction and sortCompareFunction.
2) I want to sort the data in the columns ( since it's a FileSystemDataGrid, the stuff actually displays files on the users' system ) but I want to somehow keep the folders always on top, no matter the direction of the sort ( like in Total Commander ).

Could anyone point me in an efficient direction? I'm curious if there's an easy way to do this without having to store the data in a huge array, then assign it as a data provider and stuff like that... I'm looking for a more efficient solution.

PS: I know this is not a 100% Flex related problem but I think that my chances of getting an answer for the problem are a bit higher here than in the AIR forum... anyway, this is more of a "theoretical thingie".

Thanks.

[wvxvw]

Why won't you make it part of the condition in the sorting function?
I.e. when you need to sort the files there'll be function called like this:
function someSort(a:File, b:File):int
{
if ((a.isDirectory() && b.isDirectory()) || (!a.isDirectory() && !b.isDirectory()))
{
// do the sorting by alphabet, date etc.
}
if (!b.isDirectory() && a.isDirectory()) return 1;
if (!a.isDirectory() && b.isDirectory() return -1;
}
Not sure the arguments will be files, but, they will have to provide info such as isDirectory() or something...

[fx.barrett]

Thanks for the reply. I first tried playing around with something like you posted but it didn't work... then I tried N other ways and still with no result. It's totally frustrating...

I'll give your code a shot too... hopefully, it will work...

[fx.barrett]

Nah, I can't make it work... Too tired and frustrated because I've been wasting my time with this crap since this morning... Here's how one of the compare functions looks like:

private function compareNames(item1:File, item2:File):int
{
var newItem1:Object = {type: item1.isDirectory, name: item1.name};
var newItem2:Object = {type: item2.isDirectory, name: item2.name};

var collection:ArrayCollection = new ArrayCollection();
collection.addItem(newItem1);
collection.addItem(newItem2);

var collectionSort:Sort = new Sort();
collectionSort.fields = [new SortField("type", false), new SortField("name", true)];
collection.sort = collectionSort;
collection.refresh();

if (collection.getItemIndex(newItem1) > collection.getItemIndex(newItem2)) return -1;
else if (collection.getItemIndex(newItem1) < collection.getItemIndex(newItem2)) return 1;
else return 0;
}

I have no bloody idea how to sort those items correctly...

EDIT: Another thing that I was trying is to somehow sort the data again after the compareFunction finishes but this time only after type ( so I can push directories to the top ) but again, no luck...

One more idea that came to my mind is to somehow determine the direction of the sort... if I know the direction then I could associate it with the SortField and hopefully solve the problem... or something... I'm really lost...

[wvxvw]

Can you just sort the ArrayCollection.source and then refresh the collection? I find this Sort thing very uncomfortable and compilcating...

[fx.barrett]

EDIT: :D Ok, sorting the source and the stuff I'm doing seems quite the same... What's the difference ( except that with the source you are working with an Array and with the Sort you are working with an ArrayCollection )?

I think I'm asking too much here: could you perhaps throw together an extremely fast example? Just place a FileSystemDataGrid into a new AIR application and see if you can sort the name column so the folders remain on the top no matter the sort direction ( ASC or DESC ).

[fx.barrett]

Ok, nevermind. Problem solved with the help of your first post... Everything was cool just that my sorting was bad... had to check for DESC or ASC first to reverse the stuff...

[wvxvw]

Cool :) I was just lazy to start yet another project to try it... glad it was solved before I even started :)

[fx.barrett]

In case someone else runs into something liks this then the code would look something like this:

private function compareNames(item1:File, item2:File):int
{
if((item1.isDirectory && item2.isDirectory) ||
(!item1.isDirectory && !item2.isDirectory))
{
var itemName1:String = item1.name.toLowerCase();
var itemName2:String = item2.name.toLowerCase();

if(itemName1 == itemName2) return 0;
else if(itemName1 > itemName2) return 1;
else return -1;

}else if(item1.isDirectory && !item2.isDirectory)
{
if(dgcolName.sortDescending)
return 1;
else
return -1;
}
else if(!item1.isDirectory && item2.isDirectory)
{
if(dgcolName.sortDescending)
return -1;
else
return 1;
}
else
return 0;
}

"dgcolName" is the ID of the column you are trying to sort.