File uploading in SilverStripe - silverstripe

Question

I try to make a simple letters storage:
Letter.php:
class Letter extends DataObject
{
private static $db = array (
'DateUpload' => 'Date',
'LetterNumber' => 'Text',
'Theme' => 'Text',
'Sender' => 'Text',
'SendTo' => 'Text'
);
private static $has_many = array (
'LetterFiles' => 'LetterFiles'
);
public function getCMSFields(){
$fields = FieldList::create (
TextField::create('Theme','Theme'),
DropdownField::create('Sender','Sender'),
...
$uploader = UploadField::create('FileName','Attached Files')
)
...
}
}
LetterFiles.php:
class LetterFiles extends File
{
private static $has_one = array (
'LetterOfFile' => 'Letter'
);
}
LetterAdmin.php:
class LetterAdmin extends ModelAdmin
{
private static $managed_models = array (
'Letter'
);
private static $menu_title = 'Letters';
private static $url_segment = 'letters';
}
But when creating a new letter in the admin interface I can't attach a file: I can upload it, but after pressing the button "Save" I can not see it in the "Attached Files" field.

Answer 1

Your UploadField should use the relation you have on your DataObject. In your case, that would be 'LetterFiles':
$uploader = UploadField::create('LetterFiles', 'Attached Files')
Another minor thing: I strongly suggest you don't use File subclasses for custom file-relations. It'll only work when you upload files directly, if you upload a file somewhere else in the CMS (eg. the assets-admin) and want to link them using the "Choose existing" dialog, then it'll fail.
I suggest you just delete the LetterFiles class and use a many_many relation on your DataObject. Example:
// Change from this…
private static $has_many = array (
'LetterFiles' => 'LetterFiles'
);
// … to this:
private static $many_many = array (
'LetterFiles' => 'File'
);