Hi there,

first off all, I'm using SilverStripe 3.2 RC1.

I need to modify the shown fields of a gridfield item if you click on it. To accomplish this I'm modifying the 'GridFieldDetailForm' fields like that

$bundleGridForm = $bundleGridConfig->getComponentByType('GridFieldDetailForm');

$detailFormFields = FieldList::create(
  TabSet::create(
    'Root',
    Tab::create(
      'Haupt-Inhalt',
      CheckboxSetField::create(
        'ManyMany[AvailableVariations]',
        'Verfügbare Variationen',
        $HELP-NEEDED-HERE->VariationItems()->map()->toArray()
      )
    )
  )
);

$bundleGridForm->setFields($detailFormFields);

As you can see, I'd like to only display an CheckboxSetField and as source

$HELP-NEEDED-HERE->VariationItems()->map()->toArray()

I'd like to use a realation (VariationItems) of the currently selected / clicked item.

The Problem is I don't know how to get this Relation, because $this is of course referencing to the class, where my gridfield is on and not to the clicked item.

Perhapse the handleItem() function is what I need because it returns the GridFieldDetailForm_ItemRequest class where I can than call the getRecord() function. But all of this presupposes that I get the request form the gridfield to use the handleItem() function and I absolutely can't figure out how to get this record.

For any help I would be very grateful.

Best Regards

to answer my own question and for anyone who get also stuck here:

    $bundleGridConfig
      ->removeComponentsByType('GridFieldAddNewButton');
    
    $bundleGridForm = $bundleGridConfig->getComponentByType('GridFieldDetailForm');
    // reset all fields, either you'r just adding new fields below
    $bundleGridForm->setFields(FieldList::create());
    $bundleGridForm->setItemEditFormCallback(function($form) {
      $record = $form->getRecord();

      // get the saved values 
      $availableVariations = $this->Items()->getExtraData('AvailableVariations', $record->ID);
    
      $form->Fields()->push(
        CheckboxSetField::create(
          'VariationList',
          'Verfügbare Variationen',
          $record->VariationItems(),
          // use the saved values as preset
          explode(',', $availableVariations['AvailableVariations'])
        )
      );
    
      // workaround for https://github.com/silverstripe/silverstripe-framework/issues/4067
      $form->Fields()->push(
        HiddenField::create('ManyMany[AvailableVariations]', 'Verfügbare Variationen', $availableVariations['AvailableVariations'])
      );
    });

the problem is that there is a bug, which prevents that CheckboxSetFields get written to the database. As a quick workaround, my CheckboxSetField is just a "pseudo-field" to display the checkboxes and the field to save the selected options to the database is a HiddenField.

All you have to do now, is to parse the selected options as a string and insert this string into the hidden field on any change of the CheckboxSetField.