Sorting list of VirtualPages on a field from its Page - silverstripe

Question

I have an AreaPage with $many_many VirtualPages:
class AreaPage extends Page {
/**
* #var array
*/
private static $many_many = [
'RelatedVirtualPages' => 'VirtualPage'
];
// ...
}
The RelatedVirtualPages are copying content from ContentPages:
class ContentPage extends Page {
/**
* #var array
*/
private static $db = [
'Highlighted' => 'Boolean'
];
// ...
}
What's the best way to sort RelatedVirtualPages on the Highlighted db field of the ContentPage that it's copying?

Answer 1

Virtual Pages could be pointed at pages of different types and there is no enforcement that all of those pages are ContentPages, or at least pages that have a Hightlighted db field. You can ensure this manually when you create your SiteTree, but users could come along and screw it up so keep this in mind.
Here is some psuedo-code that might help you get started. It assumes that all virtual pages are ContentPages. If you will have multiple types of VirtualPages referenced by an AreaPage then this is probably not sufficient.
$virtualPages = $myAreaPage->RelatedVirtualPages();
$contentSourcePages = ContentPage::get()->byIDs($virtualPage->column('CopyContentFromID'));
$sortedSourcePages = $contentSourcePages->sort('Highlighted','ASC');
You possibly could also use an innerJoin, but then you have to deal with _Live tables and possibly multiple page tables (again if not just using ContentPage as VirtualPage) which could lead to some complicated scenarios.
Update
So, to summarize in my own words, you need a list of the VirtualContentPages linked to a specific AreaPage sorted on the Highlighted field from the ContentPage that each VirtualContentPage links to. If this summary is accurate, would this work:
$sortedVirtualPages = $myAreaPage->RelatedVirtualPages()
->innerJoin('ContentPage', '"ContentPage"."ID" = "VirtualContentPage"."CopyContentFromID"')
->sort('Highlighted DESC');

Answer 2

I could not find a very clean method, but did find two ways to achieve this. The function goes in the class AreaPage
First
public function getRelatedVirtualPages()
{
$items = $this->getManyManyComponents('RelatedVirtualPages');
$highlighted = $items->filterByCallback(function($record, $list) {
if($record->CopyContentFrom() instanceOf ContentPage) {
//return ! $record->CopyContentFrom()->Highlighted; // ASC
return $record->CopyContentFrom()->Highlighted; // DESC
}
});
$highlighted->merge($items);
$highlighted->removeDuplicates();
return $highlighted;
}
Second (the method you described in the comments)
public function getRelatedVirtualPages()
{
$items = $this->getManyManyComponents('RelatedVirtualPages');
$arrayList = new ArrayList();
foreach($items as $virtualPage)
{
if($virtualPage->CopyContentFrom() instanceOf ContentPage) {
$virtualPage->Highlighted = $virtualPage->CopyContentFrom()->Highlighted;
$arrayList->push($virtualPage);
}
}
$arrayList = $arrayList->sort('Highlighted DESC');
return $arrayList;
}
I'm not very proud of any of these solutions, but I believe they do fit your criteria.

Answer 3

Here's what I ended up doing, which I think works:
/**
* #return ArrayList
*/
public function VirtualPages()
{
$result = [];
$virtualPages = $this->RelatedVirtualPages();
$contentPages = ContentPage::get()
->byIDs($virtualPages->column('CopyContentFromID'))
->map('ID', 'Highlighted')
->toArray();
foreach($virtualPages as $virtualPage) {
$highlighted = $contentPages[$virtualPage->CopyContentFromID];
$virtualPage->Highlighted = $highlighted;
$result[] = $virtualPage;
}
return ArrayList::create(
$result
);
}
And then it's sortable like so:
$areaPage->VirtualPages()->sort('Highlighted DESC');
Thank you for all the answers and pointers. I'll wait a bit before marking any answer.

Answer 4

Couldn't you just do
//just get one areapage
$AreaPageItem = AreaPage::get()->First();
//now get the RelatedVirtualPages sorted
$related_pages = $AreaPageItem->RelatedVirtualPages()->sort("Highlighted","ASC");