V2.4: getMessages and getChildFolders are empty

[Pixolantis]

If I have a folder and want to read the subfolders or messages from it, the output is always empty. But if I count the contents, I get an output:

        $mailFolderId = 'AA......=';
        $mailFolders = $graphServiceClient->users()->byUserId($userId)->mailFolders()->byMailFolderId($mailFolderId)->get()->wait();
        $checkFolderId = $mailFolders->getId(); // Result: Correct Id
        echo 'Count child folder: '.$mailFolders->getChildFolderCount().'<br>'; // Result: 4
        echo 'Count total items: '.$mailFolders->getTotalItemCount().'<br>'; // Result: 10
        //$childFolders = $mailFolders->getChildFolders(); // Result: null
        //$childFolders = $mailFolders->getMessages(); // Result: null

If I make a query for subfolders and messages with the folderId, it works and I also get the corresponding values:

        $subMailFolders = $graphServiceClient->users()->byUserId($userId)->mailFolders()->byMailFolderId($mailFolderId)->childFolders()->get()->wait();
        $messages = $graphServiceClient->users()->byUserId($userId)->mailFolders()->byMailFolderId($mailFolderId)->messages()->get()->wait();

Is this a bug or am I missing something?

Edit: The same with getAttachments()

[petrhollayms]

Hi @Pixolantis ,

Looking at the API documentation, childFolders is a relationship which needs to be read separately by using the https://learn.microsoft.com/en-us/graph/api/mailfolder-list-childfolders?view=graph-rest-1.0&tabs=php#example-1-list-mail-folders
as in your working query.

See also https://learn.microsoft.com/en-us/graph/api/resources/mailfolder?view=graph-rest-1.0

[Pixolantis]

Thank you. This is ok.

I was just a little confused by the two functions and therefore expected a corresponding output.