NEW Port betterbuttons to framework (#8569)

* MINOR: Add `Previous`, `Next` and `Create New` actions in edit form

If the form is opened via a grid field, the filters will be retained so the previous/next record opened will be correct

* MINOR: Add ability to customise the visibility of the `Previous`, `Next` and `Add` buttons at a `GridField` level

* Fix invalid action when pressing the `New` button in an edit form unless `betterbuttons` module was installed

* - Merge `showPrevious` and `showNext` to `showPagination` for grid fields
- Update documentation
- Improve performance for next/previous buttons by not fetching all list records
- Refactoring

* Refactor to fail gracefully on GridFieldPaginator

_config/buttons.yml

@@ -0,0 +1,7 @@
+---
+Name: buttons
+---
+SilverStripe\Forms\GridField\GridFieldDetailForm_ItemRequest:
+  formActions:
+    showPagination: true
+    showAdd: true

docs/en/02_Developer_Guides/15_Customising_the_Admin_Interface/How_Tos/Customise_CMS_Menu.md

@@ -124,6 +124,27 @@ SilverStripe\Admin\LeftAndMain:
     'Feedback': ''
 ```
 
+## Customising the CMS form actions
+
+The `Previous`, `Next` and `Add` actions on the edit form are visible by default but can be hidden globally by adding the following `.yml` config:
+
+```yml
+SilverStripe\Forms\GridField\GridFieldDetailForm_ItemRequest:
+  formActions:
+    showPagination: false
+    showAdd: false
+```
+
+You can also override this for a specific `GridField` instance when using the `GridFieldConfig_RecordEditor` constructor:
+
+```php
+$grid = new GridField(
+    "pages", 
+    "All Pages", 
+    SiteTree::get(), 
+    GridFieldConfig_RecordEditor::create(null, false, false));
+```
+
 ## Related
 
  * [How to extend the CMS interface](extend_cms_interface)

src/Forms/GridField/GridFieldConfig_RecordEditor.php

@@ -10,8 +10,10 @@ class GridFieldConfig_RecordEditor extends GridFieldConfig
     /**
      *
      * @param int $itemsPerPage - How many items per page should show up
+     * @param bool $showPagination Whether the `Previous` and `Next` buttons should display or not, leave as null to use default
+     * @param bool $showAdd Whether the `Add` button should display or not, leave as null to use default
      */
-    public function __construct($itemsPerPage = null)
+    public function __construct($itemsPerPage = null, $showPagination = null, $showAdd = null)
     {
         parent::__construct();
 
@@ -26,7 +28,7 @@ public function __construct($itemsPerPage = null)
         $this->addComponent(new GridField_ActionMenu());
         $this->addComponent(new GridFieldPageCount('toolbar-header-right'));
         $this->addComponent($pagination = new GridFieldPaginator($itemsPerPage));
-        $this->addComponent(new GridFieldDetailForm());
+        $this->addComponent(new GridFieldDetailForm(null, $showPagination, $showAdd));
 
         $sort->setThrowExceptionOnBadDataType(false);
         $filter->setThrowExceptionOnBadDataType(false);

src/Forms/GridField/GridFieldDetailForm.php

@@ -38,11 +38,20 @@ class GridFieldDetailForm implements GridField_URLHandler
     protected $template = null;
 
     /**
-     *
      * @var string
      */
     protected $name;
 
+    /**
+     * @var bool
+     */
+    protected $showPagination;
+
+    /**
+     * @var bool
+     */
+    protected $showAdd;
+
     /**
      * @var Validator The form validator used for both add and edit fields.
      */
@@ -79,10 +88,14 @@ public function getURLHandlers($gridField)
      * controller who wants to display the getCMSFields
      *
      * @param string $name The name of the edit form to place into the pop-up form
+     * @param bool $showPagination Whether the `Previous` and `Next` buttons should display or not, leave as null to use default
+     * @param bool $showAdd Whether the `Add` button should display or not, leave as null to use default
      */
-    public function __construct($name = 'DetailForm')
+    public function __construct($name = null, $showPagination = null, $showAdd = null)
     {
-        $this->name = $name;
+        $this->setName($name ?: 'DetailForm');
+        $this->setShowPagination($showPagination);
+        $this->setShowAdd($showAdd);
     }
 
     /**
@@ -93,6 +106,10 @@ public function __construct($name = 'DetailForm')
      */
     public function handleItem($gridField, $request)
     {
+        if ($gridStateStr = $request->getVar('gridState')) {
+            $gridField->getState(false)->setValue($gridStateStr);
+        }
+
         // Our getController could either give us a true Controller, if this is the top-level GridField.
         // It could also give us a RequestHandler in the form of GridFieldDetailForm_ItemRequest if this is a
         // nested GridField.
@@ -102,7 +119,7 @@ public function handleItem($gridField, $request)
         if (is_numeric($request->param('ID'))) {
             /** @var Filterable $dataList */
             $dataList = $gridField->getList();
-            $record = $dataList->byID($request->param("ID"));
+            $record = $dataList->byID($request->param('ID'));
         } else {
             $record = Injector::inst()->create($gridField->getModelClass());
         }
@@ -179,6 +196,68 @@ public function getName()
         return $this->name;
     }
 
+    /**
+     * @return bool
+     */
+    protected function getDefaultShowPagination()
+    {
+        $formActionsConfig = GridFieldDetailForm_ItemRequest::config()->get('formActions');
+        return isset($formActionsConfig['showPagination']) ? (boolean) $formActionsConfig['showPagination'] : false;
+    }
+
+    /**
+     * @return bool
+     */
+    public function getShowPagination()
+    {
+        if ($this->showPagination === null) {
+            return $this->getDefaultShowPagination();
+        }
+
+        return (boolean) $this->showPagination;
+    }
+
+    /**
+     * @param bool|null $showPagination
+     * @return GridFieldDetailForm
+     */
+    public function setShowPagination($showPagination)
+    {
+        $this->showPagination = $showPagination;
+        return $this;
+    }
+
+    /**
+     * @return bool
+     */
+    protected function getDefaultShowAdd()
+    {
+        $formActionsConfig = GridFieldDetailForm_ItemRequest::config()->get('formActions');
+        return isset($formActionsConfig['showAdd']) ? (boolean) $formActionsConfig['showAdd'] : false;
+    }
+
+    /**
+     * @return bool
+     */
+    public function getShowAdd()
+    {
+        if ($this->showAdd === null) {
+            return $this->getDefaultShowAdd();
+        }
+
+        return (boolean) $this->showAdd;
+    }
+
+    /**
+     * @param bool|null $showAdd
+     * @return GridFieldDetailForm
+     */
+    public function setShowAdd($showAdd)
+    {
+        $this->showAdd = $showAdd;
+        return $this;
+    }
+
     /**
      * @param Validator $validator
      * @return $this
@@ -232,8 +311,8 @@ public function getItemRequestClass()
     {
         if ($this->itemRequestClass) {
             return $this->itemRequestClass;
-        } elseif (ClassInfo::exists(static::class . "_ItemRequest")) {
-            return static::class . "_ItemRequest";
+        } elseif (ClassInfo::exists(static::class . '_ItemRequest')) {
+            return static::class . '_ItemRequest';
         } else {
             return GridFieldDetailForm_ItemRequest::class;
         }

src/Forms/GridField/GridFieldDetailForm_ItemRequest.php

@@ -7,9 +7,12 @@
 use SilverStripe\Control\HTTPRequest;
 use SilverStripe\Control\HTTPResponse;
 use SilverStripe\Control\RequestHandler;
+use SilverStripe\Core\Config\Config;
+use SilverStripe\Forms\CompositeField;
 use SilverStripe\Forms\FieldList;
 use SilverStripe\Forms\Form;
 use SilverStripe\Forms\FormAction;
+use SilverStripe\Forms\HiddenField;
 use SilverStripe\Forms\LiteralField;
 use SilverStripe\ORM\ArrayList;
 use SilverStripe\ORM\DataObject;
@@ -278,6 +281,7 @@ protected function getFormActions()
         $canEdit = $this->record->canEdit();
         $canDelete = $this->record->canDelete();
         $actions = new FieldList();
+
         if ($this->record->ID !== 0) {
             if ($canEdit) {
                 $actions->push(FormAction::create('doSave', _t('SilverStripe\\Forms\\GridField\\GridFieldDetailForm.Save', 'Save'))
@@ -290,6 +294,45 @@ protected function getFormActions()
                     ->setUseButtonTag(true)
                     ->addExtraClass('btn-outline-danger btn-hide-outline font-icon-trash-bin action--delete'));
             }
+
+            $gridStateStr = $this->getRequest()->requestVar('gridState');
+
+            $this->gridField->getState(false)->setValue($gridStateStr);
+            $actions->push(HiddenField::create('gridState', null, $gridStateStr));
+
+            $rightGroup = CompositeField::create()->setName('RightGroup');
+            $rightGroup->addExtraClass('right');
+            $rightGroup->setFieldHolderTemplate(get_class($rightGroup) . '_holder_buttongroup');
+
+            $previousAndNextGroup = CompositeField::create()->setName('PreviousAndNextGroup');
+            $previousAndNextGroup->addExtraClass('rounded');
+            $previousAndNextGroup->setFieldHolderTemplate(get_class($previousAndNextGroup) . '_holder_buttongroup');
+
+
+            $component = $this->gridField->getConfig()->getComponentByType(GridFieldDetailForm::class);
+
+            if ($component->getShowPagination()) {
+                $previousAndNextGroup->push(FormAction::create('doPrevious')
+                    ->setUseButtonTag(true)
+                    ->setAttribute('data-grid-state', $gridStateStr)
+                    ->setDisabled(!$this->getPreviousRecordID())
+                    ->addExtraClass('btn btn-secondary font-icon-left-open action--previous discard-confirmation'));
+
+                $previousAndNextGroup->push(FormAction::create('doNext')
+                    ->setUseButtonTag(true)
+                    ->setAttribute('data-grid-state', $gridStateStr)
+                    ->setDisabled(!$this->getNextRecordID())
+                    ->addExtraClass('btn btn-secondary font-icon-right-open action--next discard-confirmation'));
+            }
+
+            $rightGroup->push($previousAndNextGroup);
+
+            if ($component->getShowAdd()) {
+                $rightGroup->push(FormAction::create('doNew')
+                    ->setUseButtonTag(true)
+                    ->setAttribute('data-grid-state', $this->getRequest()->getVar('gridState'))
+                    ->addExtraClass('btn btn-primary font-icon-plus rounded action--new discard-confirmation'));
+            }
         } else { // adding new record
             //Change the Save label to 'Create'
             $actions->push(FormAction::create('doSave', _t('SilverStripe\\Forms\\GridField\\GridFieldDetailForm.Create', 'Create'))
@@ -309,7 +352,13 @@ protected function getFormActions()
                 $actions->push(new LiteralField('cancelbutton', $text));
             }
         }
+
         $this->extend('updateFormActions', $actions);
+
+        if (isset($rightGroup)) {
+            $actions->push($rightGroup);
+        }
+
         return $actions;
     }
 
@@ -410,6 +459,108 @@ public function doSave($data, $form)
         return $this->redirectAfterSave($isNewRecord);
     }
 
+    /**
+     * Goes to the previous record
+     * @param  array $data The form data
+     * @param  Form $form The Form object
+     * @return HTTPResponse
+     */
+    public function doPrevious($data, $form)
+    {
+        $this->getToplevelController()->getResponse()->addHeader('X-Pjax', 'Content');
+        $link = $this->getEditLink($this->getPreviousRecordID());
+        return $this->redirect($link);
+    }
+
+    /**
+     * Goes to the next record
+     * @param  array $data The form data
+     * @param  Form $form The Form object
+     * @return HTTPResponse
+     */
+    public function doNext($data, $form)
+    {
+        $this->getToplevelController()->getResponse()->addHeader('X-Pjax', 'Content');
+        $link = $this->getEditLink($this->getNextRecordID());
+        return $this->redirect($link);
+    }
+
+    /**
+     * Creates a new record. If you're already creating a new record,
+     * this forces the URL to change.
+     *
+     * @param  array $data The form data
+     * @param  Form $form The Form object
+     * @return HTTPResponse
+     */
+    public function doNew($data, $form)
+    {
+        return $this->redirect(Controller::join_links($this->gridField->Link('item'), 'new'));
+    }
+
+    /**
+     * Gets the edit link for a record
+     *
+     * @param  int $id The ID of the record in the GridField
+     * @return string
+     */
+    public function getEditLink($id)
+    {
+        return Controller::join_links(
+            $this->gridField->Link(),
+            'item',
+            $id,
+            '?gridState=' . urlencode($this->gridField->getState(false)->Value())
+        );
+    }
+
+    /**
+     * @param int $offset The offset from the current record
+     * @return int|bool
+     */
+    private function getAdjacentRecordID($offset)
+    {
+        $gridField = $this->getGridField();
+        $gridStateStr = $this->getRequest()->requestVar('gridState');
+        $state = $gridField->getState(false);
+        $state->setValue($gridStateStr);
+        $data = $state->getData();
+        $paginator = $data->getData('GridFieldPaginator');
+        if (!$paginator) {
+            return false;
+        }
+
+        $currentPage = $data->getData('GridFieldPaginator')->getData('currentPage');
+        $itemsPerPage = $data->getData('GridFieldPaginator')->getData('itemsPerPage');
+
+        $limit = $itemsPerPage + 2;
+        $limitOffset = max(0, $itemsPerPage * ($currentPage-1) -1);
+
+        $map = $gridField->getManipulatedList()->limit($limit, $limitOffset)->column('ID');
+        $index = array_search($this->record->ID, $map);
+        return isset($map[$index+$offset]) ? $map[$index+$offset] : false;
+    }
+
+    /**
+     * Gets the ID of the previous record in the list.
+     *
+     * @return int
+     */
+    public function getPreviousRecordID()
+    {
+        return $this->getAdjacentRecordID(-1);
+    }
+
+    /**
+     * Gets the ID of the next record in the list.
+     *
+     * @return int
+     */
+    public function getNextRecordID()
+    {
+        return $this->getAdjacentRecordID(1);
+    }
+
     /**
      * Response object for this request after a successful save
      *

src/Forms/GridField/GridFieldEditButton.php

@@ -62,7 +62,12 @@ public function getExtraData($gridField, $record, $columnName)
      */
     public function getUrl($gridField, $record, $columnName)
     {
-        return Controller::join_links($gridField->Link('item'), $record->ID, 'edit');
+        return Controller::join_links(
+            $gridField->Link('item'),
+            $record->ID,
+            'edit',
+            '?gridState=' . urlencode($gridField->getState(false)->Value())
+        );
     }
 
     /**