Extension exercises - solution

GridFieldSortOptionSet.php

<?php

/**
 * Add an OptionSetField of sort options
 */
class GridFieldSortOptionSet implements GridField_HTMLProvider, GridField_DataManipulator,
	GridField_ActionProvider, GridField_ColumnProvider {

	protected $suppressOnSort = array();

	public function augmentColumns($gridField, &$columns) {
		if($column = $gridField->State->GridFieldSortOptionSet->SortColumn.'') {
			if($this->suppressOnSort) {
				foreach($this->suppressOnSort as $component) {
					$gridField->getConfig()->removeComponentsByType($component);
				}
			}
		}
	}
	public function getColumnsHandled($gridField) { return array(); }
	public function getColumnContent($gridField, $record, $columnName) {}
	public function getColumnAttributes($gridField, $record, $columnName) {}
	public function getColumnMetadata($gridField, $columnName) {}

	/**
	 * Returns the optionset in the header
	 */
	public function getHTMLFragments($gridField) {

		$buttons ="Sort by:";

		$buttons .= GridField_FormAction::create(
			$gridField, 'SetSort', 'Custom order', 'SetSort', array(
				'SortColumn' => '',
				'SortDir' => '',
			))->Field();

		$columns = $gridField->getColumns();
		$list = $gridField->getList();
		$state = $gridField->State->GridFieldSortOptionSet;

		foreach($columns as $column) {
			if($list->canSortBy($column)) {
				$metadata = $gridField->getColumnMetadata($column);
				$sortDir = ($state->SortColumn == $column && $state->SortDir == 'ASC') ? 'DESC' : 'ASC';

				$buttons .= GridField_FormAction::create(
					$gridField, 'SetSort',
					$metadata['title'],
					'SetSort', array(
						'SortColumn' => $column.'',
						'SortDir' => $sortDir,
					))->Field();
			}
		}

		return array(
			'toolbar-header-right' => $buttons,
		);
	}

	public function setComponentsToSupressOnSort($suppressOnSort) {
		if(!is_array($suppressOnSort)) $suppressOnSort = array($suppressOnSort);

		$this->suppressOnSort = $suppressOnSort;
	}

	public function getManipulatedData(GridField $gridField, SS_List $dataList) {
		$state = $gridField->State->GridFieldSortOptionSet;
		if($state->SortColumn) {
			return $dataList->sort(''.$state->SortColumn, (''.$state->SortDir)?(''.$state->SortDir):'ASC');
		} else {
			return $dataList;
		}

	}

	public function getActions($gridField) {
		return array('SetSort');
	}

	public function handleAction(GridField $gridField, $actionName, $arguments, $data) {
		$gridField->State->GridFieldSortOptionSet->SortColumn = $arguments['SortColumn'];
		$gridField->State->GridFieldSortOptionSet->SortDir = $arguments['SortDir'];
	}
}