MDL-11047 quiz: enable sequential navigation

mod/quiz/attempt.php

@@ -98,6 +98,10 @@
 
 // Update attempt page
 if ($attemptobj->get_currentpage() != $page) {
+    if ($attemptobj->get_navigation_method() == QUIZ_NAVMETHOD_SEQ && $attemptobj->get_currentpage() > $page) {
+        // Prevent out of sequence access
+        redirect($attemptobj->start_attempt_url(null, $attemptobj->get_currentpage()));
+    }
     $DB->set_field('quiz_attempts', 'currentpage', $page);
 }
 

mod/quiz/attemptlib.php

@@ -178,6 +178,11 @@ public function get_quiz_name() {
         return $this->quiz->name;
     }
 
+    /** @return int the quiz navigation method. */
+    public function get_navigation_method() {
+        return $this->quiz->navmethod;
+    }
+
     /** @return int the number of attempts allowed at this quiz (0 = infinite). */
     public function get_num_attempts_allowed() {
         return $this->quiz->attempts;
@@ -545,6 +550,11 @@ public function get_quiz_name() {
         return $this->quizobj->get_quiz_name();
     }
 
+    /** @return int the quiz navigation method. */
+    public function get_navigation_method() {
+        return $this->quizobj->get_navigation_method();
+    }
+
     /** @return object the course_module object. */
     public function get_cm() {
         return $this->quizobj->get_cm();
@@ -708,6 +718,21 @@ public function check_review_capability() {
         }
     }
 
+    /**
+     * Checks whether a user may navigate to a particular slot
+     */
+    public function can_navigate_to($slot) {
+        switch ($this->get_navigation_method()) {
+            case QUIZ_NAVMETHOD_FREE:
+                return true;
+                break;
+            case QUIZ_NAVMETHOD_SEQ:
+                return false;
+                break;
+        }
+        return true;
+    }
+
     /**
      * @return int one of the mod_quiz_display_options::DURING,
      *      IMMEDIATELY_AFTER, LATER_WHILE_OPEN or AFTER_CLOSE constants.
@@ -1314,6 +1339,7 @@ public function get_question_buttons() {
             $button->id          = 'quiznavbutton' . $slot;
             $button->number      = $qa->get_question()->_number;
             $button->stateclass  = $qa->get_state_class($showcorrectness);
+            $button->navmethod   = $this->attemptobj->get_navigation_method();
             if (!$showcorrectness && $button->stateclass == 'notanswered') {
                 $button->stateclass = 'complete';
             }
@@ -1380,7 +1406,11 @@ public function user_picture() {
  */
 class quiz_attempt_nav_panel extends quiz_nav_panel_base {
     public function get_question_url($slot) {
-        return $this->attemptobj->attempt_url($slot, -1, $this->page);
+        if ($this->attemptobj->can_navigate_to($slot)) {
+            return $this->attemptobj->attempt_url($slot, -1, $this->page);
+        } else {
+            return null;
+        }
     }
 
     public function render_before_button_bits(mod_quiz_renderer $output) {

mod/quiz/backup/moodle2/backup_quiz_stepslib.php

@@ -42,7 +42,7 @@ protected function define_structure() {
         $quiz = new backup_nested_element('quiz', array('id'), array(
             'name', 'intro', 'introformat', 'timeopen',
             'timeclose', 'preferredbehaviour', 'attempts_number',
-            'attemptonlast', 'grademethod', 'decimalpoints', 'questiondecimalpoints',
+            'attemptonlast', 'grademethod', 'navmethod', 'decimalpoints', 'questiondecimalpoints',
             'reviewattempt', 'reviewcorrectness', 'reviewmarks',
             'reviewspecificfeedback', 'reviewgeneralfeedback',
             'reviewrightanswer', 'reviewoverallfeedback',

mod/quiz/db/install.xml

@@ -26,8 +26,9 @@
         <FIELD NAME="reviewgeneralfeedback" TYPE="int" LENGTH="6" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="Whether users are allowed to review their quiz attempts at various times. A bit field, like reviewattempt." PREVIOUS="reviewspecificfeedback" NEXT="reviewrightanswer"/>
         <FIELD NAME="reviewrightanswer" TYPE="int" LENGTH="6" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="Whether users are allowed to review their quiz attempts at various times. A bit field, like reviewattempt." PREVIOUS="reviewgeneralfeedback" NEXT="reviewoverallfeedback"/>
         <FIELD NAME="reviewoverallfeedback" TYPE="int" LENGTH="6" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="Whether users are allowed to review their quiz attempts at various times. A bit field, like reviewattempt." PREVIOUS="reviewrightanswer" NEXT="questionsperpage"/>
-        <FIELD NAME="questionsperpage" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false" PREVIOUS="reviewoverallfeedback" NEXT="shufflequestions"/>
-        <FIELD NAME="shufflequestions" TYPE="int" LENGTH="4" NOTNULL="true" DEFAULT="0" SEQUENCE="false" PREVIOUS="questionsperpage" NEXT="shuffleanswers"/>
+        <FIELD NAME="questionsperpage" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false" PREVIOUS="reviewoverallfeedback" NEXT="navmethod"/>
+        <FIELD NAME="navmethod" TYPE="char" LENGTH="16" NOTNULL="true" DEFAULT="free" SEQUENCE="false" PREVIOUS="questionsperpage" NEXT="shufflequestions"/>
+        <FIELD NAME="shufflequestions" TYPE="int" LENGTH="4" NOTNULL="true" DEFAULT="0" SEQUENCE="false" PREVIOUS="navmethod" NEXT="shuffleanswers"/>
         <FIELD NAME="shuffleanswers" TYPE="int" LENGTH="4" NOTNULL="true" DEFAULT="0" SEQUENCE="false" PREVIOUS="shufflequestions" NEXT="questions"/>
         <FIELD NAME="questions" TYPE="text" NOTNULL="true" SEQUENCE="false" PREVIOUS="shuffleanswers" NEXT="sumgrades"/>
         <FIELD NAME="sumgrades" TYPE="number" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false" DECIMALS="5" PREVIOUS="questions" NEXT="grade"/>

mod/quiz/db/upgrade.php

@@ -82,6 +82,18 @@ function xmldb_quiz_upgrade($oldversion) {
         upgrade_mod_savepoint(true, 2011120703, 'quiz');
     }
 
+    if ($oldversion < 2011120704) {
+        // Configuration option for navigation method
+        $table = new xmldb_table('quiz');
+
+        $field = new xmldb_field('navmethod', XMLDB_TYPE_CHAR, '16', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, 'free');
+
+        if (!$dbman->field_exists($table, $field)) {
+            $dbman->add_field($table, $field);
+        }
+        upgrade_mod_savepoint(true, 2011120704, 'quiz');
+    }
+
     return true;
 }
 

mod/quiz/lang/en/quiz.php

@@ -163,6 +163,7 @@
 $string['configintro'] = 'The values you set here define the default values that are used in the settings form when you create a new quiz. You can also configure which quiz settings are considered advanced.';
 $string['configmaximumgrade'] = 'The default grade that the quiz grade is scaled to be out of.';
 $string['confignewpageevery'] = 'When adding questions to the quiz page breaks will automatically be inserted according to the setting you choose here.';
+$string['confignavmethod'] = 'In Free navigation, questions may be answered in any order using navigation. In Sequential, questions must be answered in strict sequence.';
 $string['configpenaltyscheme'] = 'Penalty subtracted for each wrong response in adaptive mode.';
 $string['configpopup'] = 'Force the attempt to open in a popup window, and use JavaScript tricks to try to restrict copy and paste, etc. during quiz attempts.';
 $string['configrequirepassword'] = 'Students must enter this password before they can attempt the quiz.';
@@ -412,6 +413,10 @@
 $string['multipleanswers'] = 'Choose at least one answer.';
 $string['multiplier'] = 'Multiplier';
 $string['name'] = 'Name';
+$string['navmethod'] = 'Navigation method';
+$string['navmethod_free'] = 'Free';
+$string['navmethod_help'] = 'When sequential navigation is enabled a student must progress through the quiz in order and may not return to previous pages nor skip ahead.';
+$string['navmethod_seq'] = 'Sequential';
 $string['navnojswarning'] = 'Warning: these links will not save your answers. Use the next button at the bottom of the page.';
 $string['neverallononepage'] = 'Never, all questions on one page';
 $string['newattemptfail'] = 'Error: Could not start a new attempt at the quiz';
@@ -625,6 +630,7 @@
 $string['response'] = 'Response';
 $string['responses'] = 'Responses';
 $string['results'] = 'Results';
+$string['returnattempt'] = 'Return to attempt';
 $string['reuseifpossible'] = 'reuse previously removed';
 $string['reverttodefaults'] = 'Revert to quiz defaults';
 $string['review'] = 'Review';

mod/quiz/lib.php

@@ -58,6 +58,13 @@
  */
 define('QUIZ_MAX_EVENT_LENGTH', 5*24*60*60); // 5 days
 
+/**#@+
+ * Options for navigation method within quizzes.
+ */
+define('QUIZ_NAVMETHOD_FREE', 'free');
+define('QUIZ_NAVMETHOD_SEQ',  'sequential');
+/**#@-*/
+
 /**
  * Given an object containing all the necessary data,
  * (defined by the form in mod_form.php) this function
@@ -1745,3 +1752,13 @@ function quiz_page_type_list($pagetype, $parentcontext, $currentcontext) {
         'mod-quiz-edit'=>get_string('page-mod-quiz-edit', 'quiz'));
     return $module_pagetype;
 }
+
+/**
+ * @return the options for quiz navigation.
+ */
+function quiz_get_navigation_options() {
+    return array(
+        QUIZ_NAVMETHOD_FREE => get_string('navmethod_free', 'quiz'),
+        QUIZ_NAVMETHOD_SEQ  => get_string('navmethod_seq', 'quiz')
+    );
+}

mod/quiz/mod_form.php

@@ -154,6 +154,13 @@ protected function definition() {
         $mform->addHelpButton('questionsperpagegrp', 'newpage', 'quiz');
         $mform->setAdvanced('questionsperpagegrp', $quizconfig->questionsperpage_adv);
 
+        // Navigation method
+        $mform->addElement('select', 'navmethod', get_string('navmethod', 'quiz'),
+                quiz_get_navigation_options());
+        $mform->addHelpButton('navmethod', 'navmethod', 'quiz');
+        $mform->setAdvanced('navmethod', $quizconfig->navmethod_adv);
+        $mform->setDefault('navmethod', $quizconfig->navmethod);
+
         //-------------------------------------------------------------------------------
         $mform->addElement('header', 'interactionhdr', get_string('questionbehaviour', 'quiz'));
 

mod/quiz/renderer.php

@@ -312,7 +312,7 @@ public function navigation_panel(quiz_nav_panel_base $panel) {
      * @param quiz_nav_question_button $button
      */
     protected function render_quiz_nav_question_button(quiz_nav_question_button $button) {
-        $classes = array('qnbutton', $button->stateclass);
+        $classes = array('qnbutton', $button->stateclass, $button->navmethod);
         $attributes = array();
 
         if ($button->currentpage) {
@@ -338,13 +338,17 @@ protected function render_quiz_nav_question_button(quiz_nav_question_button $but
         $a = new stdClass();
         $a->number = $button->number;
         $a->attributes = implode(' ', $attributes);
-
-        return html_writer::link($button->url,
-                html_writer::tag('span', '', array('class' => 'thispageholder')) .
-                html_writer::tag('span', '', array('class' => 'trafficlight')) .
-                get_string($qnostring, 'quiz', $a),
-                array('class' => implode(' ', $classes), 'id' => $button->id,
-                        'title' => $button->statestring));
+        $tagcontents = html_writer::tag('span', '', array('class' => 'thispageholder')) .
+                        html_writer::tag('span', '', array('class' => 'trafficlight')) .
+                        get_string($qnostring, 'quiz', $a);
+        $tagattributes = array('class' => implode(' ', $classes), 'id' => $button->id,
+                                  'title' => $button->statestring);
+
+        if ($button->url) {
+            return html_writer::link($button->url, $tagcontents, $tagattributes);
+        } else {
+            return html_writer::tag('span', $tagcontents, $tagattributes);
+        }
     }
 
     /**
@@ -572,9 +576,13 @@ public function summary_table($attemptobj, $displayoptions) {
                 $flag = html_writer::empty_tag('img', array('src' => $this->pix_url('i/flagged'),
                         'alt' => get_string('flagged', 'question'), 'class' => 'questionflag'));
             }
-            $row = array(html_writer::link($attemptobj->attempt_url($slot),
-                    $attemptobj->get_question_number($slot) . $flag),
-                    $attemptobj->get_question_status($slot, $displayoptions->correctness));
+            if ($attemptobj->can_navigate_to($slot)) {
+                $row = array(html_writer::link($attemptobj->attempt_url($slot),
+                        $attemptobj->get_question_number($slot) . $flag),
+                        $attemptobj->get_question_status($slot, $displayoptions->correctness));
+            } else {
+                $row = array($attemptobj->get_question_number($slot) . $flag, $attemptobj->get_question_status($slot, $displayoptions->correctness));
+            }
             if ($markscolumn) {
                 $row[] = $attemptobj->get_question_mark($slot);
             }
@@ -599,6 +607,12 @@ public function summary_page_controls($attemptobj) {
         // countdown timer
         $output .= $this->countdown_timer();
 
+        // Return to place button
+        $button = new single_button(
+                new moodle_url($attemptobj->attempt_url(null, $attemptobj->get_currentpage())), get_string('returnattempt', 'quiz'));
+        $output .= $this->container($this->container($this->render($button),
+                'controls'), 'submitbtns mdl-align');
+
         // Finish attempt button.
         $options = array(
             'attempt' => $attemptobj->get_attemptid(),

mod/quiz/settings.php

@@ -89,6 +89,11 @@
         get_string('newpageevery', 'quiz'), get_string('confignewpageevery', 'quiz'),
         array('value' => 1, 'fix' => false), $perpage));
 
+// Navigation method
+$quizsettings->add(new admin_setting_configselect_with_advanced('quiz/navmethod',
+        get_string('navmethod', 'quiz'), get_string('confignavmethod', 'quiz'),
+        array('value' => QUIZ_NAVMETHOD_FREE, 'adv' => true), quiz_get_navigation_options()));
+
 // Shuffle within questions
 $quizsettings->add(new admin_setting_configcheckbox_with_advanced('quiz/shuffleanswers',
         get_string('shufflewithin', 'quiz'), get_string('configshufflewithin', 'quiz'),

mod/quiz/styles.css

@@ -21,8 +21,6 @@ body.jsenabled .questionflagcheckbox {display: none;}
 .path-mod-quiz #user-picture img {width: auto;height: auto;float: left;}
 
 .path-mod-quiz .qnbutton {display: block; position: relative; float: left; width: 1.5em; height: 1.5em; overflow: hidden; margin: 0.3em 0.3em 0.3em 0; padding: 0; border: 1px solid #bbb; background: #ddd; text-align: center; vertical-align: middle;line-height: 1.5em !important; font-weight: bold; text-decoration: none;}
-.path-mod-quiz .qnbutton:hover {text-decoration: underline;}
-.path-mod-quiz .qnbutton span {cursor: pointer; cursor: hand;}
 
 .path-mod-quiz .qnbutton .trafficlight,
 .path-mod-quiz .qnbutton .thispageholder {display: block; position: absolute; top: 0; bottom: 0; left: 0; right: 0;}
@@ -43,6 +41,9 @@ body.jsenabled .questionflagcheckbox {display: none;}
 .path-mod-quiz .qnbutton.notanswered .trafficlight,
 .path-mod-quiz .qnbutton.incorrect .trafficlight {border-top: 3px solid #800;}
 
+.path-mod-quiz .qnbutton.free:hover {text-decoration: underline;}
+.path-mod-quiz .qnbutton.free span {cursor: pointer; cursor: hand;}
+
 .path-mod-quiz .othernav {clear: both; margin: 0.5em 0;}
 .path-mod-quiz .othernav a,
 .path-mod-quiz .othernav input {display: block;margin: 0.5em 0;}

mod/quiz/version.php

@@ -25,7 +25,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$module->version   = 2011120703;       // The current module version (Date: YYYYMMDDXX)
+$module->version   = 2011120704;       // The current module version (Date: YYYYMMDDXX)
 $module->requires  = 2011112900;       // Requires this Moodle version
 $module->component = 'mod_quiz';       // Full name of the plugin (used for diagnostics)
 $module->cron      = 60;