silverstripe-dms/docs/en/manage-related-documents.md

Manage related documents

You can relate documents to each other using the GridField under "Related Documents" in the CMS.

Add related documents

You can use the model relationship DMSDocument::RelatedDocuments to modify the DataList and save as required:

$parentDocument = DMSDocument::get()->byId(123);

$relatedDocument = DMSDocument::get()->byId(234);

$parentDocument->RelatedDocuments()->add($relatedDocument);

Using the relationship method directly will skip the extension hook available in getRelatedDocuments (see below).

Modifying the related documents list

If you need to modify the related documents DataList returned by the ORM, use the updateRelatedDocuments extension hook provided by DMSDocument::getRelatedDocuments:

# MyExtension is an extension applied to DMSDocument
class MyExtension extends DataExtension
{
    public function updateRelatedDocuments($relatedDocuments)
    {
        foreach ($relatedDocuments as $document) {
            // Add square brackets around the description
            $document->Description = '[' . $document->Description . ']';
        }
        return $relatedDocuments;
    }
}

Retrieving related documents

To retrieve a DataList of related documents you can either use getRelatedDocuments or the ORM relationship method RelatedDocuments directly. The former will allow extensions to modify the list, whereas the latter will not.

$relatedDocuments = $document->getRelatedDocuments();

foreach ($relatedDocuments as $relatedDocument) {
    // ...
}