Delete action not possible in read-only GridFieldDetailForm

[baukezwaan]

Module version(s) affected

5.3.0

Description

For gridfields with records that can only be viewed and deleted (not edited), there should be a delete button on the delete button on the GridFieldDetailForm. This has been fixed in the past, since the code specifically tries to solve this specific scenario. But the delete button is in a inactive state, so deleting is not possible for the user:

How to reproduce

Reproduction by creating a Model with canEdit = false and canDelete = true
And a page where the read-only gridfield is shown.

ExampleModel.php

    class ExampleModel extends DataObject
    {

        private static $table_name = 'ExampleModel';

        private static $db = [
            'Title' => 'Varchar(75)',
            'Score' => 'Int'
        ];

        private static $has_one = [
            'Page' => Page::class
        ];

        public function canEdit($member = null)
        {
            return false;
        }

        public function canDelete($member = null)
        {
            return true;
        }
    }

Page.php

      class Page extends SiteTree
      {
          private static $db = [];

          public function getCMSFields()
          {
              $fields = parent::getCMSFields();

              $gridfield = GridField::create('Example', 'ExampleModels', $this->ExampleModels(), GridFieldConfig_RecordViewer::create());

              $fields->addFieldToTab('Root.Test', $gridfield);

              return $fields;
          }

      }
    

Possible Solution

In the method ItemEditForm() there is a solution made for this specific scenario:

see

silverstripe-framework/src/Forms/GridField/GridFieldDetailForm_ItemRequest.php

Lines 265 to 271 in 5fa5a0c

	if ($this->record->ID && (!$this->record->hasMethod('canEdit') || !$this->record->canEdit())) {
	// Restrict editing of existing records
	$form->makeReadonly();
	// Hack to re-enable delete button if user can delete
	if ($this->record->hasMethod('canDelete') && $this->record->canDelete()) {
	$form->Actions()->fieldByName('action_doDelete')->setReadonly(false);
	}

But in the view()-method, where this ItemEditForm() is called, the ->makeReadOnly() seems to be undoing the effort:

see

silverstripe-framework/src/Forms/GridField/GridFieldDetailForm_ItemRequest.php

Lines 143 to 144 in 5fa5a0c

	$form = $this->ItemEditForm();
	$form->makeReadonly();

Validations

• Check that there isn't already an issue that reports the same bug
• Double check that your reproduction steps work in a fresh installation of silverstripe/installer (with any code examples you've provided)

[GuySartorelli]

Care will have to be taken when fixing this that sudo mode still doesn't allow performing a delete action if the form is protected.

It would probably also make sense for the delete action to be disabled by default for a regular readonly GridFieldDetailForm and have to be enabled either at a project level or a gridfield level.