This is a Hook which is responsible for flexform manipulations depending on the chosen controller action (switchableControllerAction). Following Hook file is located in typo3conf/ext/your_ext/Classes/Hooks/T3libBefunc.php You need to register this Hook within your ext_localconf: $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_befunc…

TYPO3 Extension - Hook - Flexform Manipulaltion - T3libBefunc.php

<?php
/***************************************************************
 *  Copyright notice
 *
 *  (c) 2012-2013 Andy Hausmann <ah@sota-studio.de>, sota studio
 *  All rights reserved
 *
 *  This script is part of the TYPO3 project. The TYPO3 project is
 *  free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  The GNU General Public License can be found at
 *  http://www.gnu.org/copyleft/gpl.html.
 *
 *  This script is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  This copyright notice MUST APPEAR in all copies of the script!
 ***************************************************************/

/**
 * Hook into t3lib_befunc to change Flexform behavior depending on detected action
 *
 * @package TYPO3
 * @subpackage your_ext
 */
class Tx_YourExt_Hooks_T3libBefunc
{
  /** @var string Extension key of this Extension */
	static protected $extKey = 'your_ext';

	/** @var array List of Plugins names to react to */
	protected $pluginNames = array(
		'core', 'widgets'
	);

	/**
	 * Mapping for Controller->Action pair and removable fields.
	 * The first one acts as default respectively fallback one.
	 *
	 * Convention for structure:
	 *
	 * Controller->action => array(
	 *   flexformTreeNode => fields,to,remove
	 * )
   * 
   * Mentioned fields are prefixed in Flexforms by 'settings.'
   * Method 'deleteFromStructure' can easily be manipulated in order to allow definiting of non-prefixed fields.
   * I've just chosen this kind of declaration, because i mostly want to make every Flexform setting available within the Fluid templates.
	 *
	 * @var array The Mapping
	 */
	protected $fieldMap = array(
		'ControllerOne->index' 	=> array(
			'sDEF' => 'fieldOne,fieldTwo'
		),
		'ControllerOne->map'		=> array(
			'sDEF' => 'fieldOne,fieldTwo',
      'template' => 'fieldFive,fieldSix'
		),
		'ControllerOne->list'	=> array(
			'sDEF' => 'fieldOne,fieldTwo,fieldThree'
		),
		'ControllerOne->search'	=> array(
			'sDEF' => 'fieldFour'
		),
		'ControllerOne->detail' 	=> array(
			'sDEF' => ''
		),
		'ControllerTwo->index'		=> array(
			'sDEF' => ''
		)
	);


	/**
	 * Returns the Extension key.
	 *
	 * @return string The Extension key.
	 */
	static public function getExtKey() {
		return self::$extKey;
	}

	/**
	 * Returns the Extension name, transformed into a Plugin signature prefix.
	 * E.g.: xt_name becomes ExtName, return value will be extname.
	 *
	 * @return string Plugin signature prefix
	 */
	protected function getPluginPrefix() {
		$extName = t3lib_div::underscoredToUpperCamelCase(self::$extKey);
		return strtolower($extName); //
	}

	/**
	 * Returns a list of Plugins to react to.
	 *
	 * @return array List of Plugins
	 */
	protected function getPlugins() {
		$plugins = array();
		foreach ($this->pluginNames as $k => $v) {
			array_push($plugins, $this->getPluginPrefix() . '_' . $v);
		}
		return $plugins;
	}

	/**
	 * Returns the first defined Controller-Action pair configured.
	 * The first one also acts as default/fallback.
	 *
	 * @return string Default pair of Controller and Action.
	 */
	protected function getDefaultControllerAndAction() {
		reset($this->fieldMap);
		return key($this->fieldMap);
	}

	/**
	 * Returns the removable fields depending on the chosen Controller and Action.
	 *
	 * @param string $controllerActionPair
	 * @return array
	 */
	protected function getRemovableFields($controllerActionPair) {
		return (is_array($this->fieldMap[$controllerActionPair]))
			? $this->fieldMap[$controllerActionPair]
			: array();
	}

	protected function allowedToAct($listType) {
		return (in_array($listType, $this->getPlugins()))
			? true
			: false;
	}

	/**
	 * Hook function of t3lib_befunc
	 * It is used to change the flexform if it is about news
	 *
	 * @param array &$dataStructure Flexform structure
	 * @param array $conf some strange configuration
	 * @param array $row row of current record
	 * @param string $table table name
	 * @param string $fieldName some strange field name
	 * @return void
	 */
	public function getFlexFormDS_postProcessDS(&$dataStructure, $conf, $row, $table, $fieldName) {
		if ($this->allowedToAct($row['list_type']) && $table === 'tt_content' && is_array($dataStructure)) {
			$this->updateFlexforms($dataStructure, $row);
		}
	}

	/**
	 * Update flexform configuration if a action is selected
	 *
	 * @param array|string &$dataStructure flexform structure
	 * @param array $row row of current record
	 * @return void
	 */
	protected function updateFlexforms(array &$dataStructure, array $row) {
		$selectedView = '';

		// Get selected action
		$flexform = t3lib_div::xml2array($row['pi_flexform']);
		if (is_array($flexform) && is_array($flexform['data'])) {
			$selectedView = $flexform['data']['sDEF']['lDEF']['switchableControllerActions']['vDEF'];
			if (!empty($selectedView)) {
				$actionParts = t3lib_div::trimExplode(';', $selectedView, true);
				$selectedView = $actionParts[0];
			}

		// If new plugin element
		} elseif (t3lib_div::isFirstPartOfStr($row['uid'], 'NEW')) {
			$selectedView = $this->getDefaultControllerAndAction();
		} else {
			$selectedView = $this->getDefaultControllerAndAction();
		}

		if (!empty($selectedView)) {
			$this->deleteFromStructure($dataStructure, $this->getRemovableFields($selectedView));

			if (is_array($GLOBALS['TYPO3_CONF_VARS']['EXT'][$this->extKey]['Hooks/T3libBefunc.php']['updateFlexforms'])) {
				$params = array(
					'selectedView' => $selectedView,
					'dataStructure' => &$dataStructure,
				);
				foreach ($GLOBALS['TYPO3_CONF_VARS']['EXT'][$this->extKey]['Hooks/T3libBefunc.php']['updateFlexforms'] as $reference) {
					t3lib_div::callUserFunction($reference, $params, $this);
				}
			}
		}
	}

	/**
	 * Remove fields from flexform structure
	 *
	 * @param array &$dataStructure flexform structure
	 * @param array $fieldsToBeRemoved fields which need to be removed
	 * @return void
	 */
	protected function deleteFromStructure(array &$dataStructure, array $fieldsToBeRemoved) {
		foreach ($fieldsToBeRemoved as $sheetName => $sheetFields) {
			$fieldsInSheet = t3lib_div::trimExplode(',', $sheetFields, true);

			foreach ($fieldsInSheet as $fieldName) {
				unset($dataStructure['sheets'][$sheetName]['ROOT']['el']['settings.' . $fieldName]);
			}
		}
	}
}

$extKey = Tx_YourExt_Hooks_T3libBefunc::getExtKey();

if (defined('TYPO3_MODE') && $TYPO3_CONF_VARS[TYPO3_MODE]['XCLASS']['ext/' . $extKey . '/Classes/Hooks/T3libBefunc.php']) {
	require_once ($TYPO3_CONF_VARS[TYPO3_MODE]['XCLASS']['ext/' . $extKey . '/Classes/Hooks/T3libBefunc.php']);
}