From 6cc1599e09a84831c17dd46c935f202190325b02 Mon Sep 17 00:00:00 2001
From: Andreas Grabs <info@grabs-edv.de>
Date: Fri, 4 Jun 2010 20:21:08 +0000
Subject: [PATCH] captcha now uses the recaptcha-plugin and some code cleanups

---
 mod/feedback/analysis.php                  |   7 +-
 mod/feedback/analysis_course.php           |   5 +-
 mod/feedback/analysis_to_excel.php         |   7 +-
 mod/feedback/edit_item.php                 |  45 +---
 mod/feedback/item/captcha/lib.php          | 243 ++++++++++-----------
 mod/feedback/item/feedback_item_class.php  | 160 ++++++++------
 mod/feedback/item/info/lib.php             |   5 +-
 mod/feedback/item/label/lib.php            |  11 +-
 mod/feedback/item/multichoice/lib.php      |   6 +-
 mod/feedback/item/multichoicerated/lib.php |   4 +-
 mod/feedback/item/numeric/lib.php          |   5 +-
 mod/feedback/item/textarea/lib.php         |   7 +-
 mod/feedback/item/textfield/lib.php        |   5 +-
 mod/feedback/lang/en/feedback.php          |   2 +
 mod/feedback/lib.php                       |  86 +++-----
 15 files changed, 288 insertions(+), 310 deletions(-)

diff --git a/mod/feedback/analysis.php b/mod/feedback/analysis.php
index 5a79c00d78c..78f46d52b39 100644
--- a/mod/feedback/analysis.php
+++ b/mod/feedback/analysis.php
@@ -127,11 +127,10 @@ if($check_anonymously) {
     foreach($items as $item) {
         if($item->hasvalue == 0) continue;
         echo '<table width="100%" class="generalbox">';
+        
         //get the class of item-typ
-        $itemclass = 'feedback_item_'.$item->typ;
-        //get the instance of the item-class
-        require_once($CFG->dirroot.'/mod/feedback/item/'.$item->typ.'/lib.php');
-        $itemobj = new $itemclass();
+        $itemobj = feedback_get_item_class($item->typ);
+        
         $itemnr++;
         if($feedback->autonumbering) {
             $printnr = $itemnr.'.';
diff --git a/mod/feedback/analysis_course.php b/mod/feedback/analysis_course.php
index 3ea09ba3902..a6ccf103cab 100644
--- a/mod/feedback/analysis_course.php
+++ b/mod/feedback/analysis_course.php
@@ -168,10 +168,7 @@ if ($courseitemfilter > 0) {
         if($item->hasvalue == 0) continue;
         echo '<table width="100%" class="generalbox">';
         //get the class from item-typ
-        $itemclass = 'feedback_item_'.$item->typ;
-        //get the instance of the item-class
-        require_once($CFG->dirroot.'/mod/feedback/item/'.$item->typ.'/lib.php');
-        $itemobj = new $itemclass();
+        $itemobj = feedback_get_item_class($item->typ);
         $itemnr++;
         if($feedback->autonumbering) {
             $printnr = $itemnr.'.';
diff --git a/mod/feedback/analysis_to_excel.php b/mod/feedback/analysis_to_excel.php
index baf26c5b6b6..de2923da7ca 100644
--- a/mod/feedback/analysis_to_excel.php
+++ b/mod/feedback/analysis_to_excel.php
@@ -185,9 +185,7 @@ if (empty($items)) {
 }
 foreach($items as $item) {
     //get the class of item-typ
-    $itemclass = 'feedback_item_'.$item->typ;
-    //get the instance of the item-class
-    $itemobj = new $itemclass();
+    $itemobj = feedback_get_item_class($item->typ);
     $rowOffset1 = $itemobj->excelprint_item($worksheet1, $rowOffset1, $xlsFormats, $item, $mygroupid, $coursefilter);
 }
 
@@ -295,8 +293,7 @@ function feedback_excelprint_detailed_items(&$worksheet, $xlsFormats, $completed
     foreach($items as $item) {
         $value = $DB->get_record('feedback_value', array('item'=>$item->id, 'completed'=>$completed->id));
 
-        $itemclass = 'feedback_item_'.$item->typ;
-        $itemobj = new $itemclass();
+        $itemobj = feedback_get_item_class($item->typ);
         $printval = $itemobj->get_printval($item, $value);
 
         // $worksheet->setFormat('<l><vo>');
diff --git a/mod/feedback/edit_item.php b/mod/feedback/edit_item.php
index b50446a95c8..2a0807fa9a3 100644
--- a/mod/feedback/edit_item.php
+++ b/mod/feedback/edit_item.php
@@ -84,8 +84,7 @@ if($id and $item = $DB->get_record('feedback_item', array('id'=>$id))) {
 
 require_once($CFG->dirroot.'/mod/feedback/item/'.$typ.'/lib.php');
 
-$itemclass = 'feedback_item_'.$typ;
-$itemobj = new $itemclass();
+$itemobj = feedback_get_item_class($typ);
 
 $itemobj->build_editform($item, $feedback, $cm);
 
@@ -124,48 +123,6 @@ if(isset($error)) {
 feedback_print_errors();
 $itemobj->show_editform();
 
-/*
-echo $OUTPUT->box_start('generalbox boxwidthwide boxaligncenter');
-    echo '<form action="edit_item.php" method="post">';
-    echo '<input type="hidden" name="sesskey" value="'.sesskey().'" />';
-
-//this div makes the buttons stand side by side
-echo '<div>';
-$itemclass = 'feedback_item_'.$typ;
-$itemobj = new $itemclass();
-$itemobj->show_edit($item, $usehtmleditor);
-echo '</div>';
-    echo '<input type="hidden" name="id" value="'.$id.'" />';
-    echo '<input type="hidden" name="itemid" value="'.(isset($item->id)?$item->id:'').'" />';
-    echo '<input type="hidden" name="typ" value="'.$typ.'" />';
-    echo '<input type="hidden" name="feedbackid" value="'.$feedback->id.'" />';
-
-//choose the position
-$lastposition = $DB->count_records('feedback_item', array('feedback'=>$feedback->id));
-echo get_string('position', 'feedback').'&nbsp;';
-echo '<select name="position">';
-    //Dropdown-Items for choosing the position
-    if($position == -1){
-        feedback_print_numeric_option_list(1, $lastposition + 1, $lastposition + 1);
-    }else {
-        feedback_print_numeric_option_list(1, $lastposition, $item->position);
-    }
-echo '</select><hr />';
-
-//////////////////////////////////////////////////////////////////////////////////////
-//////////////////////////////////////////////////////////////////////////////////////
-if(!empty($item->id)){
-    echo '<input type="hidden" id="updateitem" name="updateitem" value="1" />';
-    echo '<input type="submit" value ="'.get_string('update_item', 'feedback').'" />';
-}else{
-    echo '<input type="hidden" id="saveitem" name="saveitem" value="1" />';
-    echo '<input type="submit" value="'.get_string('save_item', 'feedback').'" />';
-}
-echo '<input type="submit" name="cancel" value="'.get_string('cancel').'" />';
-echo '</form>';
-//////////////////////////////////////////////////////////////////////////////////////
-//////////////////////////////////////////////////////////////////////////////////////
-*/
 // echo $OUTPUT->box_end();
 
 if ($typ!='label') {
diff --git a/mod/feedback/item/captcha/lib.php b/mod/feedback/item/captcha/lib.php
index c334a75d902..fb87fe4ea82 100644
--- a/mod/feedback/item/captcha/lib.php
+++ b/mod/feedback/item/captcha/lib.php
@@ -5,74 +5,73 @@ require_once($CFG->dirroot.'/mod/feedback/item/feedback_item_class.php');
 class feedback_item_captcha extends feedback_item_base {
     var $type = "captcha";
     var $commonparams;
-    var $item_form;
-    var $item;
+    var $item_form = false;
+    var $item = false;
+    var $feedback = false;
 
     function init() {
 
     }
 
     function build_editform($item, $feedback, $cm) {
-        global $DB, $CFG;
-        require_once('captcha_form.php');
+        global $DB;
+        
+        $editurl = new moodle_url('/mod/feedback/edit.php', array('id'=>$cm->id));
 
-        //get the lastposition number of the feedback_items
-        $position = $item->position;
-        $lastposition = $DB->count_records('feedback_item', array('feedback'=>$feedback->id));
-        if($position == -1){
-            $i_formselect_last = $lastposition + 1;
-            $i_formselect_value = $lastposition + 1;
-            $item->position = $lastposition + 1;
-        }else {
-            $i_formselect_last = $lastposition;
-            $i_formselect_value = $item->position;
+        //ther are no settings for recaptcha
+        if(isset($item->id) AND $item->id > 0) {
+            notice(get_string('there_are_no_settings_for_recaptcha', 'feedback'), $editurl->out());
+            exit;
         }
-        //the elements for position dropdownlist
-        $positionlist = array_slice(range(0,$i_formselect_last),1,$i_formselect_last,true);
         
-        $item->presentation = empty($item->presentation) ? 3 : $item->presentation;
-        $item->required = 1;
-
-        //all items for dependitem
-        $feedbackitems = feedback_get_depend_candidates_for_item($feedback, $item);
-        $commonparams = array('cmid'=>$cm->id,
-                             'id'=>isset($item->id) ? $item->id : NULL,
-                             'typ'=>$item->typ,
-                             'items'=>$feedbackitems,
-                             'feedback'=>$feedback->id);
-
-        //build the form
-        $this->item_form = new feedback_captcha_form('edit_item.php', array('item'=>$item, 'common'=>$commonparams, 'positionlist'=>$positionlist, 'position'=>$position));
+        //only one recaptcha can be in a feedback
+        if($DB->record_exists('feedback_item', array('feedback'=>$feedback->id, 'typ'=>$this->type))) {
+            notice(get_string('only_one_captcha_allowed', 'feedback'), $editurl->out());
+            exit;
+        }
+        
+        $this->item = $item;
+        $this->feedback = $feedback;
+        $this->item_form = true; //dummy
+        
+        $lastposition = $DB->count_records('feedback_item', array('feedback'=>$feedback->id));
+
+        $this->item->feedback = $feedback->id;
+        $this->item->template = 0;
+        $this->item->name = get_string('captcha', 'feedback');
+        $this->item->label = get_string('captcha', 'feedback');
+        $this->item->presentation = '';
+        $this->item->typ = $this->type;
+        $this->item->hasvalue = $this->get_hasvalue();
+        $this->item->position = $lastposition + 1;
+        $this->item->required = 1;
+        $this->item->dependitem = 0;
+        $this->item->dependvalue = '';
+        $this->item->options = '';
     }
 
-    //this function only can used after the call of build_editform()
     function show_editform() {
-        $this->item_form->display();
     }
     
     function is_cancelled() {
-        return $this->item_form->is_cancelled();
+        return false;
     }
 
     function get_data() {
-        if($this->item = $this->item_form->get_data()) {
-            return true;
-        }
-        return false;
+        return true;
     }
 
     function save_item() {
         global $DB;
         
-        if(!$item = $this->item_form->get_data()) {
+        if(!$this->item) {
             return false;
         }
         
-        $item->hasvalue = $this->get_hasvalue();
         if(!$item->id) {
-            $item->id = $DB->insert_record('feedback_item', $item);
+            $item->id = $DB->insert_record('feedback_item', $this->item);
         }else {
-            $DB->update_record('feedback_item', $item);
+            $DB->update_record('feedback_item', $this->item);
         }
         
         return $DB->get_record('feedback_item', array('id'=>$item->id));
@@ -91,7 +90,7 @@ class feedback_item_captcha extends feedback_item_base {
         return $itemnr;
     }
 
-    function excelprint_item(&$worksheet, $rowOffset, $item, $groupid, $courseid = false) {
+    function excelprint_item(&$worksheet, $rowOffset, $xlsFormats, $item, $groupid, $courseid = false) {
         return $rowOffset;
     }
   
@@ -103,13 +102,10 @@ class feedback_item_captcha extends feedback_item_base {
      * @return void
      */
     function print_item_preview($item) {
-        global $SESSION, $CFG, $DB, $OUTPUT;
+        global $DB;
 
         $align = right_to_left() ? 'right' : 'left';
 
-        $presentation = $item->presentation;
-        $SESSION->feedback->item->captcha->charcount = $presentation;
-
         $cmid = 0;
         $feedbackid = $item->feedback;
         if($feedbackid > 0) {
@@ -119,36 +115,14 @@ class feedback_item_captcha extends feedback_item_base {
             }
         }
 
-        if(isset($SESSION->feedback->item->captcha->checked)) {
-            $checked = $SESSION->feedback->item->captcha->checked == true;
-            unset($SESSION->feedback->item->captcha->checked);
-        }else {
-            $checked = false;
-        }
-
-        $requiredmark = ($item->required == 1)?'<span class="feedback_required_mark">*</span>':'';
+        $requiredmark = '<span class="feedback_required_mark">*</span>';
         
         //print the question and label
         echo '<div class="feedback_item_label_'.$align.'">';
         echo '('.$item->label.') ';
         echo format_text($item->name.$requiredmark, true, false, false);
-        if($item->dependitem) {
-            if($dependitem = $DB->get_record('feedback_item', array('id'=>$item->dependitem))) {
-                echo ' <span class="feedback_depend">('.$dependitem->label.'-&gt;'.$item->dependvalue.')</span>';
-            }
-        }
         echo '</div>';
         
-        //print the presentation
-        echo '<div class="feedback_item_presentation_'.$align.'">';
-            $imglink = new moodle_url('/mod/feedback/item/captcha/print_captcha.php', array('id'=>$cmid));
-            echo '<div class="feedback_item_captcha_img_'.$align.'">';
-                echo '<img alt="'.$this->type.'" src="'.$imglink->out().'" />';
-            echo '</div>';
-            echo '<div class="feedback_item_captcha_text_'.$align.'">';
-                echo '<input type="text" name="'.$item->typ.'_'.$item->id.'" size="'.$presentation.'" maxlength="'.$presentation.'" value="" />';
-            echo '</div>';
-        echo '</div>';
     }
     
     /**     
@@ -161,13 +135,11 @@ class feedback_item_captcha extends feedback_item_base {
      * @return void
      */
     function print_item_complete($item, $value = '', $highlightrequire = false) {
-        global $SESSION, $CFG, $DB, $OUTPUT;
+        global $SESSION, $CFG, $DB, $USER;
+        require_once($CFG->libdir.'/recaptchalib.php');
 
         $align = right_to_left() ? 'right' : 'left';
 
-        $presentation = $item->presentation;
-        $SESSION->feedback->item->captcha->charcount = $presentation;
-
         $cmid = 0;
         $feedbackid = $item->feedback;
         if($feedbackid > 0) {
@@ -177,42 +149,57 @@ class feedback_item_captcha extends feedback_item_base {
             }
         }
 
-        if(isset($SESSION->feedback->item->captcha->checked)) {
-            $checked = $SESSION->feedback->item->captcha->checked == true;
-            unset($SESSION->feedback->item->captcha->checked);
-        }else {
-            $checked = false;
-        }
-
         //check if an false value even the value is not required
-        if(!$item->required AND $value != '' AND $SESSION->feedback->item->captcha->checkchar != $value) {
+        if($highlightrequire AND !$this->check_value($value, $item)) {
             $falsevalue = true;
         }else {
             $falsevalue = false;
         }
 
-        if(($highlightrequire AND $item->required AND !$checked) OR $falsevalue) {
-            $highlight = ' missingrequire';
+        if($falsevalue) {
+            $highlight = 'missingrequire';
         }else {
             $highlight = '';
         }
-        $requiredmark = ($item->required == 1)?'<span class="feedback_required_mark">*</span>':'';
+        $requiredmark = '<span class="feedback_required_mark">*</span>';
         
-        //print the question and label
-        echo '<div class="feedback_item_label_'.$align.$highlight.'">';
+        if(isset($SESSION->feedback->captchacheck) AND $SESSION->feedback->captchacheck == $USER->sesskey AND $value == $USER->sesskey) {
+            //print the question and label
+            echo '<div class="feedback_item_label_'.$align.'">';
+            echo '('.$item->label.') ';
             echo format_text($item->name.$requiredmark, true, false, false);
-        echo '</div>';
-        
-        //print the presentation
-        echo '<div class="feedback_item_presentation_'.$align.'">';
-            echo '<div class="feedback_item_captcha_img_'.$align.'">';
-            $imglink = new moodle_url('/mod/feedback/item/captcha/print_captcha.php', array('id'=>$cmid));
-            echo '<img alt="'.$this->type.'" src="'.$imglink->out().'" />';
+            echo '<input type="hidden" value="'.$USER->sesskey.'" name="'.$item->typ.'_'.$item->id.'" />';
             echo '</div>';
-            echo '<div class="feedback_item_captcha_text_'.$align.'">';
-            echo '<input type="text" name="'.$item->typ.'_'.$item->id.'" size="'.$presentation.'" maxlength="'.$presentation.'" value="" />';
-            echo '</div>';
-        echo '</div>';
+            return;
+        }
+
+        $strincorrectpleasetryagain = get_string('incorrectpleasetryagain', 'auth');
+        $strenterthewordsabove = get_string('enterthewordsabove', 'auth');
+        $strenterthenumbersyouhear = get_string('enterthenumbersyouhear', 'auth');
+        $strgetanothercaptcha = get_string('getanothercaptcha', 'auth');
+        $strgetanaudiocaptcha = get_string('getanaudiocaptcha', 'auth');
+        $strgetanimagecaptcha = get_string('getanimagecaptcha', 'auth');
+
+        $recaptureoptions = Array('theme'=>'custom', 'custom_theme_widget'=>'recaptcha_widget');
+        $html = html_writer::script(js_writer::set_variable('RecaptchaOptions', $recaptureoptions));
+        $html .= '
+
+        <div  class="'.$highlight.'" id="recaptcha_widget" style="display:none">
+
+        <div id="recaptcha_image"></div>
+        <div class="recaptcha_only_if_incorrect_sol" style="color:red">' . $strincorrectpleasetryagain . '</div>
+        <span class="recaptcha_only_if_image"><label for="recaptcha_response_field">' . $strenterthewordsabove . $requiredmark. '</label></span>
+        <span class="recaptcha_only_if_audio"><label for="recaptcha_response_field">' . $strenterthenumbersyouhear . '</label></span>
+        
+        <input type="text" id="recaptcha_response_field" name="'.$item->typ.'_'.$item->id.'" />
+        
+        <div><a href="javascript:Recaptcha.reload()">' . $strgetanothercaptcha . '</a></div>
+        <div class="recaptcha_only_if_image"><a href="javascript:Recaptcha.switch_type(\'audio\')">' . $strgetanaudiocaptcha . '</a></div>
+        <div class="recaptcha_only_if_audio"><a href="javascript:Recaptcha.switch_type(\'image\')">' . $strgetanimagecaptcha . '</a></div>
+        </div>';
+        //we have to rename the challengefield
+        $captchahtml = recaptcha_get_html($CFG->recaptchapublickey, NULL);
+        echo $html.$captchahtml;
     }
 
     /**     
@@ -224,57 +211,52 @@ class feedback_item_captcha extends feedback_item_base {
      * @return void
      */
     function print_item_show_value($item, $value = '') {
-        global $SESSION, $CFG, $DB, $OUTPUT;
+        global $DB;
 
         $align = right_to_left() ? 'right' : 'left';
 
-        $presentation = $item->presentation;
-        $SESSION->feedback->item->captcha->charcount = $presentation;
-
         $cmid = 0;
-
-        if(isset($SESSION->feedback->item->captcha->checked)) {
-            $checked = $SESSION->feedback->item->captcha->checked == true;
-            unset($SESSION->feedback->item->captcha->checked);
-        }else {
-            $checked = false;
+        $feedbackid = $item->feedback;
+        if($feedbackid > 0) {
+            $feedback = $DB->get_record('feedback', array('id'=>$feedbackid));
+            if($cm = get_coursemodule_from_instance("feedback", $feedback->id, $feedback->course)) {
+                $cmid = $cm->id;
+            }
         }
 
-        $requiredmark = ($item->required == 1)?'<span class="feedback_required_mark">*</span>':'';
+        $requiredmark = '<span class="feedback_required_mark">*</span>';
         
         //print the question and label
         echo '<div class="feedback_item_label_'.$align.'">';
-            echo '('.$item->label.') ';
-            echo format_text($item->name . $requiredmark, true, false, false);
-        echo '</div>';
-        
-        //print the presentation
-        echo '<div class="feedback_item_presentation_'.$align.'">';
-            echo '<div class="feedback_item_captcha_img_'.$align.'">';
-            $imglink = new moodle_url('/mod/feedback/item/captcha/print_captcha.php', array('id'=>$cmid));
-            echo '<img alt="'.$this->type.'" src="'.$imglink->out().'" />';
-            echo '</div>';
-            echo $OUTPUT->box_start('generalbox boxalign'.$align);
-            echo $value ? $value : '&nbsp;';
-            echo $OUTPUT->box_end();
+        echo '('.$item->label.') ';
+        echo format_text($item->name.$requiredmark, true, false, false);
         echo '</div>';
     }
 
 
     function check_value($value, $item) {
-        global $SESSION;
-        //if the item is not required, so the check is true if no value is given
-        if((!isset($value) OR $value == '') AND $item->required != 1) return true;
-        if($SESSION->feedback->item->captcha->checkchar == $value) {
-            $SESSION->feedback->item->captcha->checked = true;
+        global $SESSION, $CFG, $USER;
+        require_once($CFG->libdir.'/recaptchalib.php');
+        
+        $challenge = optional_param('recaptcha_challenge_field', '', PARAM_RAW);
+        
+        if($value == $USER->sesskey AND $challenge == '') {
+            return true;
+        }
+        $remoteip = getremoteaddr(null);
+        $response = recaptcha_check_answer($CFG->recaptchaprivatekey, $remoteip, $challenge, $value);
+        if($response->is_valid) {
+            $SESSION->feedback->captchacheck = $USER->sesskey;
             return true;
         }
+        unset($SESSION->feedback->captchacheck);
+
         return false;
     }
 
     function create_value($data) {
-        $data = clean_text($data);
-        return $data;
+        global $USER;
+        return $USER->sesskey;
     }
 
     //compares the dbvalue with the dependvalue
@@ -288,11 +270,14 @@ class feedback_item_captcha extends feedback_item_base {
     }
     
     function get_presentation($data) {
-        return $data->count_of_nums;
+        return '';
     }
 
     function get_hasvalue() {
         return 1;
     }
+    
+    function can_switch_require() {
+        return false;
+    }
 }
-?>
diff --git a/mod/feedback/item/feedback_item_class.php b/mod/feedback/item/feedback_item_class.php
index e84623da312..ddcfcd71496 100644
--- a/mod/feedback/item/feedback_item_class.php
+++ b/mod/feedback/item/feedback_item_class.php
@@ -1,53 +1,51 @@
 <?php
 
-class feedback_item_base {
+abstract class feedback_item_base {
     var $type;
-    /**
-     * The class constructor
-     *
-     */
-    function feedback_item_base() {
-        $this->init();
-    }
 
     /**
-     * Fake constructor to keep PHP5 happy
+     * constructor
      *
      */
     function __construct() {
-        $this->feedback_item_base();
+        $this->init();
     }
 
-    /**
-     * prints the item-related sequenz on the edit-item form
-     *
-     * @param $item the db-object from feedback_item
-     * @param $usehtmleditor defines whether the editor should be shown or not
-     */
-    function show_edit($item, $usehtmleditor = false) {
+    //this function only can used after the call of build_editform()
+    function show_editform() {
+        $this->item_form->display();
+    }
+    
+    function is_cancelled() {
+        return $this->item_form->is_cancelled();
     }
 
-    /**
-     * returns an Array with three values(typ, name, XXX)
-     * XXX is also an Array (count of responses on type $this->type)
-     * each element is a structure (answertext, answercount)
-     * @param $item the db-object from feedback_item
-     * @param $groupid if given
-     * @param $courseid if given
-     * @return array
-    */
-    function get_analysed($item, $groupid = false, $courseid = false) {
-        return array();
+    function get_data() {
+        if($this->item = $this->item_form->get_data()) {
+            return true;
+        }
+        return false;
     }
+    
+    abstract function init();
+    abstract function build_editform($item, $feedback, $cm);
+    abstract function save_item();
+    abstract function check_value($value, $item);
+    abstract function create_value($data);
+    abstract function compare_value($item, $dbvalue, $dependvalue);
+    abstract function get_presentation($data);
+    abstract function get_hasvalue();
+    abstract function can_switch_require();
 
     /**
+     * @param object $worksheet a reference to the pear_spreadsheet-object
+     * @param integer $rowOffset
      * @param object $item the db-object from feedback_item
-     * @param string $value a item-related value from feedback_values
-     * @return string
+     * @param integer $groupid
+     * @param integer $courseid
+     * @return integer the new rowOffset
     */
-    function get_printval($item, $value) {
-      return '';
-    }
+    abstract function excelprint_item(&$worksheet, $rowOffset, $xlsFormats, $item, $groupid, $courseid = false);
 
     /**
      * @param $item the db-object from feedback_item
@@ -56,48 +54,82 @@ class feedback_item_base {
      * @param integer $courseid
      * @return integer the new itemnr
     */
-    function print_analysed($item, $itemnr = '', $groupid = false, $courseid = false) {
-      return 0;
-    }
-
+    abstract function print_analysed($item, $itemnr = '', $groupid = false, $courseid = false);
+    
     /**
-     * @param object $worksheet a reference to the pear_spreadsheet-object
-     * @param integer $rowOffset
      * @param object $item the db-object from feedback_item
-     * @param integer $groupid
-     * @param integer $courseid
-     * @return integer the new rowOffset
+     * @param string $value a item-related value from feedback_values
+     * @return string
     */
-    function excelprint_item(&$worksheet, $rowOffset, $item, $groupid, $courseid = false) {
-      return $rowOffset;
-    }
-
-    function print_item($item, $value = false, $readonly = false, $edit = false, $highlightrequire = false){
-    }
-
-    function check_value($value, $item) {
-        return true;
-    }
-
-    function create_value($data) {
-        return '';
-    }
+    abstract function get_printval($item, $value);
+    
+    /**
+     * returns an Array with three values(typ, name, XXX)
+     * XXX is also an Array (count of responses on type $this->type)
+     * each element is a structure (answertext, answercount)
+     * @param $item the db-object from feedback_item
+     * @param $groupid if given
+     * @param $courseid if given
+     * @return array
+    */
+    abstract function get_analysed($item, $groupid = false, $courseid = false);
+  
+    /**     
+     * print the item at the edit-page of feedback
+     *
+     * @global object
+     * @param object $item
+     * @return void
+     */
+    abstract function print_item_preview($item);
+    
+    /**     
+     * print the item at the complete-page of feedback
+     *
+     * @global object
+     * @param object $item
+     * @param string $value
+     * @param bool $highlightrequire
+     * @return void
+     */
+    abstract function print_item_complete($item, $value = '', $highlightrequire = false);
 
-    function get_presentation($data) {
-      return '';
-   }
+    /**     
+     * print the item at the complete-page of feedback
+     *
+     * @global object
+     * @param object $item
+     * @param string $value
+     * @return void
+     */
+    abstract function print_item_show_value($item, $value = '');
 
-    function get_hasvalue() {
-        return 0;
-    }
 }
 
 //a dummy class to realize pagebreaks
 class feedback_item_pagebreak extends feedback_item_base {
     var $type = "pagebreak";
-    function init() {
 
-    }
+    function show_editform() {}
+    function is_cancelled() {}
+    function get_data() {}
+    function init() {}
+    function build_editform($item, $feedback, $cm) {}
+    function save_item() {}
+    function check_value($value, $item) {}
+    function create_value($data) {}
+    function compare_value($item, $dbvalue, $dependvalue) {}
+    function get_presentation($data) {}
+    function get_hasvalue() {}
+    function excelprint_item(&$worksheet, $rowOffset, $xlsFormats, $item, $groupid, $courseid = false) {}
+    function print_analysed($item, $itemnr = '', $groupid = false, $courseid = false) {}
+    function get_printval($item, $value) {}
+    function get_analysed($item, $groupid = false, $courseid = false) {}
+    function print_item_preview($item) {}
+    function print_item_complete($item, $value = '', $highlightrequire = false) {}
+    function print_item_show_value($item, $value = '') {}
+    function can_switch_require(){}
+
 }
 
 
diff --git a/mod/feedback/item/info/lib.php b/mod/feedback/item/info/lib.php
index 56fdecaed12..e3ac71b4b6e 100644
--- a/mod/feedback/item/info/lib.php
+++ b/mod/feedback/item/info/lib.php
@@ -306,5 +306,8 @@ class feedback_item_info extends feedback_item_base {
     function get_hasvalue() {
         return 1;
     }
+    
+    function can_switch_require() {
+        return false;
+    }
 }
-?>
diff --git a/mod/feedback/item/label/lib.php b/mod/feedback/item/label/lib.php
index 5e85944c103..3ed84e27943 100644
--- a/mod/feedback/item/label/lib.php
+++ b/mod/feedback/item/label/lib.php
@@ -208,5 +208,14 @@ class feedback_item_label extends feedback_item_base {
     function get_hasvalue() {
         return 0;
     }
+    
+    function can_switch_require() {
+        return false;
+    }
+
+    function check_value($value, $item) {}
+    function excelprint_item(&$worksheet, $rowOffset, $xlsFormats, $item, $groupid, $courseid = false) {}
+    function print_analysed($item, $itemnr = '', $groupid = false, $courseid = false) {}
+    function get_printval($item, $value) {}
+    function get_analysed($item, $groupid = false, $courseid = false) {}
 }
-?>
\ No newline at end of file
diff --git a/mod/feedback/item/multichoice/lib.php b/mod/feedback/item/multichoice/lib.php
index 29db52175be..ff7d41f8377 100644
--- a/mod/feedback/item/multichoice/lib.php
+++ b/mod/feedback/item/multichoice/lib.php
@@ -700,6 +700,8 @@ class feedback_item_multichoice extends feedback_item_base {
         return false;
     }
     
+    
+    function can_switch_require() {
+        return true;
+    }
 }
-
-?>
diff --git a/mod/feedback/item/multichoicerated/lib.php b/mod/feedback/item/multichoicerated/lib.php
index 8ea36fc263f..9d361fc890b 100644
--- a/mod/feedback/item/multichoicerated/lib.php
+++ b/mod/feedback/item/multichoicerated/lib.php
@@ -582,6 +582,8 @@ class feedback_item_multichoicerated extends feedback_item_base {
         return false;
     }
     
+    function can_switch_require() {
+        return true;
+    }
 
 }
-?>
diff --git a/mod/feedback/item/numeric/lib.php b/mod/feedback/item/numeric/lib.php
index bbca8099a9e..4daae15336e 100644
--- a/mod/feedback/item/numeric/lib.php
+++ b/mod/feedback/item/numeric/lib.php
@@ -411,5 +411,8 @@ class feedback_item_numeric extends feedback_item_base {
     function get_hasvalue() {
         return 1;
     }
+    
+    function can_switch_require() {
+        return true;
+    }
 }
-?>
diff --git a/mod/feedback/item/textarea/lib.php b/mod/feedback/item/textarea/lib.php
index 7a45e45e0f4..bc22d8f7470 100644
--- a/mod/feedback/item/textarea/lib.php
+++ b/mod/feedback/item/textarea/lib.php
@@ -85,7 +85,7 @@ class feedback_item_textarea extends feedback_item_base {
 
 
     //liefert eine Struktur ->name, ->data = array(mit Antworten)
-    function get_analysed($item, $groupid, $courseid = false) {
+    function get_analysed($item, $groupid = false, $courseid = false) {
         global $DB;
 
         $aVal = null;
@@ -270,5 +270,8 @@ class feedback_item_textarea extends feedback_item_base {
     function get_hasvalue() {
         return 1;
     }
+    
+    function can_switch_require() {
+        return true;
+    }
 }
-?>
diff --git a/mod/feedback/item/textfield/lib.php b/mod/feedback/item/textfield/lib.php
index 669c2a89a4a..526f3f11c6e 100644
--- a/mod/feedback/item/textfield/lib.php
+++ b/mod/feedback/item/textfield/lib.php
@@ -264,5 +264,8 @@ class feedback_item_textfield extends feedback_item_base {
     function get_hasvalue() {
         return 1;
     }
+
+    function can_switch_require() {
+        return true;
+    }
 }
-?>
diff --git a/mod/feedback/lang/en/feedback.php b/mod/feedback/lang/en/feedback.php
index 9100b41cc0b..6b9a558967d 100644
--- a/mod/feedback/lang/en/feedback.php
+++ b/mod/feedback/lang/en/feedback.php
@@ -198,6 +198,7 @@ $string['numeric_range_to'] = 'Range to';
 $string['of'] = 'of';
 $string['oldvaluespreserved'] = 'All old questions and the assigned values will be preserved';
 $string['oldvalueswillbedeleted'] = 'The current questions and all your user\'s responses will be deleted';
+$string['only_one_captcha_allowed'] = 'Only one captcha is allowed in a feedback';
 $string['overview'] = 'Overview';
 $string['page'] = 'Page';
 $string['page_after_submit'] = 'Page after submit';
@@ -262,6 +263,7 @@ $string['textarea_width'] = 'Width';
 $string['textfield'] = 'Short text answer';
 $string['textfield_maxlength'] = 'Maximum characters accepted';
 $string['textfield_size'] = 'Textfield width';
+$string['there_are_no_settings_for_recaptcha'] = 'There are no settings for captcha';
 $string['this_feedback_is_already_submitted'] = 'You\'ve already completed this activity.';
 $string['timeclose'] = 'Time to close';
 $string['timeclose_help'] = 'You can specify times when the feedback is accessible for people to answer the questions. If the checkbox is not ticked there is no limit defined.';
diff --git a/mod/feedback/lib.php b/mod/feedback/lib.php
index 6730400ca75..b49009d79d5 100644
--- a/mod/feedback/lib.php
+++ b/mod/feedback/lib.php
@@ -1113,6 +1113,25 @@ function feedback_get_template_list($course, $onlyown = false) {
 ////////////////////////////////////////////////
 ////////////////////////////////////////////////
 
+/**
+ * load the lib.php from item-plugin-dir and returns the instance of the itemclass
+ *
+ * @global object
+ * @param object $item
+ * @return object the instanz of itemclass
+ */
+function feedback_get_item_class($typ) {
+    global $CFG;
+    
+    //get the class of item-typ
+    $itemclass = 'feedback_item_'.$typ;
+    //get the instance of item-class
+    if (!class_exists($itemclass)) {
+        require_once($CFG->dirroot.'/mod/feedback/item/'.$typ.'/lib.php');
+    }
+    return new $itemclass();
+}
+
 /**
  * load the available item plugins from given subdirectory of $CFG->dirroot
  * the default is "mod/feedback/item"
@@ -1213,10 +1232,7 @@ function feedback_create_item($data) {
         $item->label = get_string('no_itemlabel', 'feedback');
     }
 
-    //get the used class from item-typ
-    $itemclass = 'feedback_item_'.$data->typ;
-    //get the instance of the item class
-    $itemobj = new $itemclass();
+    $itemobj = feedback_get_item_class($data->typ);
     // $item->presentation = $itemobj->get_presentation($data);
     $item->presentation = ''; //the date comes from postupdate() of the itemobj
 
@@ -1320,9 +1336,14 @@ function feedback_delete_all_items($feedbackid){
  * @return boolean
  */
 function feedback_switch_item_required($item) {
-    global $DB;
+    global $DB, $CFG;
+
+    $itemobj = feedback_get_item_class($item->typ);
 
-    return $DB->set_field('feedback_item', 'required', (int)!(bool)$item->required, array('id'=>$item->id));
+    if($itemobj->can_switch_require()) {
+        $DB->set_field('feedback_item', 'required', (int)!(bool)$item->required, array('id'=>$item->id));
+    }
+    return true;
 }
 
 /**
@@ -1457,13 +1478,8 @@ function feedback_print_item_preview($item){
     if($item->typ == 'pagebreak') {
         return;
     }
-    //get the class of the given item-typ
-    $itemclass = 'feedback_item_'.$item->typ;
-    if (!class_exists($itemclass)) {
-        require_once($CFG->dirroot.'/mod/feedback/item/'.$item->typ.'/lib.php');
-    }
     //get the instance of the item-class
-    $itemobj = new $itemclass();
+    $itemobj = feedback_get_item_class($item->typ);
     $itemobj->print_item_preview($item);
 }
 
@@ -1482,13 +1498,8 @@ function feedback_print_item_complete($item, $value = false, $highlightrequire =
         return;
     }
 
-    //get the class of the given item-typ
-    $itemclass = 'feedback_item_'.$item->typ;
-    if (!class_exists($itemclass)) {
-        require_once($CFG->dirroot.'/mod/feedback/item/'.$item->typ.'/lib.php');
-    }
     //get the instance of the item-class
-    $itemobj = new $itemclass();
+    $itemobj = feedback_get_item_class($item->typ);
     $itemobj->print_item_complete($item, $value, $highlightrequire);
 }
 
@@ -1506,13 +1517,8 @@ function feedback_print_item_show_value($item, $value = false){
         return;
     }
     
-    //get the class of the given item-typ
-    $itemclass = 'feedback_item_'.$item->typ;
-    if (!class_exists($itemclass)) {
-        require_once($CFG->dirroot.'/mod/feedback/item/'.$item->typ.'/lib.php');
-    }
     //get the instance of the item-class
-    $itemobj = new $itemclass();
+    $itemobj = feedback_get_item_class($item->typ);
     $itemobj->print_item_show_value($item, $value);
 }
 
@@ -1833,12 +1839,9 @@ function feedback_compare_item_value($completedid, $itemid, $dependvalue, $tmp =
     
     //get the class of the given item-typ
     $item = $DB->get_record('feedback_item', array('id'=>$itemid));
-    $itemclass = 'feedback_item_'.$item->typ;
-    if (!class_exists($itemclass)) {
-        require_once($CFG->dirroot.'/mod/feedback/item/'.$item->typ.'/lib.php');
-    }
+
     //get the instance of the item-class
-    $itemobj = new $itemclass();
+    $itemobj = feedback_get_item_class($item->typ);
     return $itemobj->compare_value($item, $dbvalue, $dependvalue); //true or false
 }
 
@@ -1882,15 +1885,8 @@ function feedback_check_values($firstitem, $lastitem) {
             return false;
         }
 
-        //get the class of the item-typ
-        $itemclass = 'feedback_item_'.$item->typ;
-
-        if (!class_exists($itemclass)) {
-            require_once($CFG->dirroot.'/mod/feedback/item/'.$item->typ.'/lib.php');
-        }
-
         //get the instance of the item-class
-        $itemobj = new $itemclass();
+        $itemobj = feedback_get_item_class($item->typ);
 
         //now we let check the value by the item-class
         if(!$itemobj->check_value($value, $item)) {
@@ -1951,13 +1947,7 @@ function feedback_create_values($usrid, $timemodified, $tmp = false, $guestid =
         $value->course_id = $courseid;
         
         //get the class of item-typ
-        $itemclass = 'feedback_item_'.$item->typ;
-        
-        //get the instance of item-class
-        if (!class_exists($itemclass)) {
-            require_once($CFG->dirroot.'/mod/feedback/item/'.$item->typ.'/lib.php');
-        }
-        $itemobj = new $itemclass();
+        $itemobj = feedback_get_item_class($item->typ);
         
         //the kind of values can be absolutely different so we run create_value directly by the item-class
         $value->value = $itemobj->create_value($itemvalue);
@@ -2003,13 +1993,7 @@ function feedback_update_values($completed, $tmp = false) {
         $newvalue->course_id = $courseid;
 
         //get the class of item-typ
-        $itemclass = 'feedback_item_'.$item->typ;
-        
-        //get the instance of item-class
-        if (!class_exists($itemclass)) {
-            require_once($CFG->dirroot.'/mod/feedback/item/'.$item->typ.'/lib.php');
-        }
-        $itemobj = new $itemclass();
+        $itemobj = feedback_get_item_class($item->typ);
         //the kind of values can be absolutely different so we run create_value directly by the item-class
         $newvalue->value = $itemobj->create_value($itemvalue);
         
-- 
2.43.0