includes/actions/FormAction.php

   1 <?php
   2 /**
   3  * Base classes for actions done on pages.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  18  *
  19  * @file
  20  */
  21
  22 /**
  23  * @defgroup Actions Action done on pages
  24  */
  25
  26 /**
  27  * An action which shows a form and does something based on the input from the form
  28  */
  29 abstract class FormAction extends Action {
  30
  31         /**
  32          * Get an HTMLForm descriptor array
  33          * @return array
  34          */
  35         abstract protected function getFormFields();
  36
  37         /**
  38          * Add pre- or post-text to the form
  39          * @return string HTML which will be sent to $form->addPreText()
  40          */
  41         protected function preText() {
  42                 return '';
  43         }
  44
  45         /**
  46          * @return string
  47          */
  48         protected function postText() {
  49                 return '';
  50         }
  51
  52         /**
  53          * Play with the HTMLForm if you need to more substantially
  54          * @param HTMLForm $form
  55          */
  56         protected function alterForm( HTMLForm $form ) {
  57         }
  58
  59         /**
  60          * Get the HTMLForm to control behavior
  61          * @return HTMLForm|null
  62          */
  63         protected function getForm() {
  64                 $this->fields = $this->getFormFields();
  65
  66                 // Give hooks a chance to alter the form, adding extra fields or text etc
  67                 wfRunHooks( 'ActionModifyFormFields', array( $this->getName(), &$this->fields, $this->page ) );
  68
  69                 $form = new HTMLForm( $this->fields, $this->getContext(), $this->getName() );
  70                 $form->setSubmitCallback( array( $this, 'onSubmit' ) );
  71
  72                 // Retain query parameters (uselang etc)
  73                 $form->addHiddenField( 'action', $this->getName() ); // Might not be the same as the query string
  74                 $params = array_diff_key(
  75                         $this->getRequest()->getQueryValues(),
  76                         array( 'action' => null, 'title' => null )
  77                 );
  78                 $form->addHiddenField( 'redirectparams', wfArrayToCgi( $params ) );
  79
  80                 $form->addPreText( $this->preText() );
  81                 $form->addPostText( $this->postText() );
  82                 $this->alterForm( $form );
  83
  84                 // Give hooks a chance to alter the form, adding extra fields or text etc
  85                 wfRunHooks( 'ActionBeforeFormDisplay', array( $this->getName(), &$form, $this->page ) );
  86
  87                 return $form;
  88         }
  89
  90         /**
  91          * Process the form on POST submission.  If you return false from getFormFields(),
  92          * this will obviously never be reached.  If you don't want to do anything with the
  93          * form, just return false here
  94          * @param array $data
  95          * @return bool|array True for success, false for didn't-try, array of errors on failure
  96          */
  97         abstract public function onSubmit( $data );
  98
  99         /**
 100          * Do something exciting on successful processing of the form.  This might be to show
 101          * a confirmation message (watch, rollback, etc) or to redirect somewhere else (edit,
 102          * protect, etc).
 103          */
 104         abstract public function onSuccess();
 105
 106         /**
 107          * The basic pattern for actions is to display some sort of HTMLForm UI, maybe with
 108          * some stuff underneath (history etc); to do some processing on submission of that
 109          * form (delete, protect, etc) and to do something exciting on 'success', be that
 110          * display something new or redirect to somewhere.  Some actions have more exotic
 111          * behavior, but that's what subclassing is for :D
 112          */
 113         public function show() {
 114                 $this->setHeaders();
 115
 116                 // This will throw exceptions if there's a problem
 117                 $this->checkCanExecute( $this->getUser() );
 118
 119                 $form = $this->getForm();
 120                 if ( $form->show() ) {
 121                         $this->onSuccess();
 122                 }
 123         }
 124
 125         /**
 126          * @see Action::execute()
 127          *
 128          * @param array|null $data
 129          * @param bool $captureErrors
 130          * @throws ErrorPageError|Exception
 131          * @return bool
 132          */
 133         public function execute( array $data = null, $captureErrors = true ) {
 134                 try {
 135                         // Set a new context so output doesn't leak.
 136                         $this->context = clone $this->getContext();
 137
 138                         // This will throw exceptions if there's a problem
 139                         $this->checkCanExecute( $this->getUser() );
 140
 141                         $fields = array();
 142                         foreach ( $this->fields as $key => $params ) {
 143                                 if ( isset( $data[$key] ) ) {
 144                                         $fields[$key] = $data[$key];
 145                                 } elseif ( isset( $params['default'] ) ) {
 146                                         $fields[$key] = $params['default'];
 147                                 } else {
 148                                         $fields[$key] = null;
 149                                 }
 150                         }
 151                         $status = $this->onSubmit( $fields );
 152                         if ( $status === true ) {
 153                                 // This might do permanent stuff
 154                                 $this->onSuccess();
 155                                 return true;
 156                         } else {
 157                                 return false;
 158                         }
 159                 }
 160                 catch ( ErrorPageError $e ) {
 161                         if ( $captureErrors ) {
 162                                 return false;
 163                         } else {
 164                                 throw $e;
 165                         }
 166                 }
 167         }
 168 }