In Silverstripe, how can I automate the CMS field creation for Pages like it works in DataObjects? - silverstripe

Question

In DataObjects, the getCMSFields method creates all the appropriate CMS Fields automatically (it is called scaffolding). However, in classes that extend SiteTree (i.e. Pages) this does not happen.
How can I use this form field scaffolding in Pages?

Answer 1

Besides calling DataObject::getCMSFields() as you already suggested in your own answer, it is also possible to instantiate a scafolder directly:
public function getCMSFields() {
// with tabs
$scaffolder = new FormScaffolder($this);
$scaffolder->restrictFields = ['Title', 'Content'];
$scaffolder->tabbed = true;
$fields = $scaffolder->getFieldList();
$fields->addFieldToTab('Root.Main', [
new MySpecialFieldWithCustomOptions('Links', 'My Links', $foobar),
]);
return $fields;
}
public function getCMSFields() {
// without tabs
$scaffolder = new FormScaffolder($this);
$scaffolder->restrictFields = ['Title', 'Content'];
$fields = $scaffolder->getFieldList();
$fields->push(
new MySpecialFieldWithCustomOptions('Links', 'My Links', $foobar)
);
return $fields;
}
This will work with any DataObject ($this has to be an instace of DataObject). Pages a subclass of DataObjects.
restrictFields is optional, if not provided, it will do all fields it can find.

Answer 2

We go back to DataObject and get the scaffolded fields:
use SilverStripe\ORM\DataObject;
use Page;
class MyPage extends Page
{
private static $db = [
'MyField' => 'Varchar',
];
private static $has_one = [
'MyRelation' => 'MyClass',
];
public function getCMSFields()
{
// fields from Page class
$fields = parent::getCMSFields();
// fields from DataObject class.
$fieldRepository = DataObject::getCMSFields();
$fields->addFieldsToTab(
'Root.MyExtraFields',
[
$fieldRepository->dataFieldByName('MyField'),
$fieldRepository->dataFieldByName('MyRelationID'),
]
);
return $fields;
}
}