question/behaviour/interactive/behaviour.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Question behaviour where the student can submit questions one at a
  19  * time for immediate feedback.
  20  *
  21  * @package    qbehaviour
  22  * @subpackage interactive
  23  * @copyright  2009 The Open University
  24  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  25  */
  26
  27
  28 defined('MOODLE_INTERNAL') || die();
  29
  30
  31 /**
  32  * Question behaviour for the interactive model.
  33  *
  34  * Each question has a submit button next to it which the student can use to
  35  * submit it. Once the qustion is submitted, it is not possible for the
  36  * student to change their answer any more, but the student gets full feedback
  37  * straight away.
  38  *
  39  * @copyright  2009 The Open University
  40  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  41  */
  42 class qbehaviour_interactive extends question_behaviour_with_multiple_tries {
  43     /**
  44      * Special value used for {@link question_display_options::$readonly when
  45      * we are showing the try again button to the student during an attempt.
  46      * The particular number was chosen randomly. PHP will treat it the same
  47      * as true, but in the renderer we reconginse it display the try again
  48      * button enabled even though the rest of the question is disabled.
  49      * @var integer
  50      */
  51     const READONLY_EXCEPT_TRY_AGAIN = 23485299;
  52
  53     public function is_compatible_question(question_definition $question) {
  54         return $question instanceof question_automatically_gradable;
  55     }
  56
  57     public function get_right_answer_summary() {
  58         return $this->question->get_right_answer_summary();
  59     }
  60
  61     /**
  62      * @return bool are we are currently in the try_again state.
  63      */
  64     protected function is_try_again_state() {
  65         $laststep = $this->qa->get_last_step();
  66         return $this->qa->get_state()->is_active() && $laststep->has_behaviour_var('submit') &&
  67                 $laststep->has_behaviour_var('_triesleft');
  68     }
  69
  70     public function adjust_display_options(question_display_options $options) {
  71         // We only need different behaviour in try again states.
  72         if (!$this->is_try_again_state()) {
  73             parent::adjust_display_options($options);
  74             if ($this->qa->get_state() == question_state::$invalid &&
  75                     $options->marks == question_display_options::MARK_AND_MAX) {
  76                 $options->marks = question_display_options::MAX_ONLY;
  77             }
  78             return;
  79         }
  80
  81         // Let the hint adjust the options.
  82         $hint = $this->get_applicable_hint();
  83         if (!is_null($hint)) {
  84             $hint->adjust_display_options($options);
  85         }
  86
  87         // Now call the base class method, but protect some fields from being overwritten.
  88         $save = clone($options);
  89         parent::adjust_display_options($options);
  90         $options->feedback = $save->feedback;
  91         $options->numpartscorrect = $save->numpartscorrect;
  92
  93         // In a try-again state, everything except the try again button
  94         // Should be read-only. This is a mild hack to achieve this.
  95         if (!$options->readonly) {
  96             $options->readonly = self::READONLY_EXCEPT_TRY_AGAIN;
  97         }
  98     }
  99
 100     public function get_applicable_hint() {
 101         if (!$this->is_try_again_state()) {
 102             return null;
 103         }
 104         return $this->question->get_hint(count($this->question->hints) -
 105                 $this->qa->get_last_behaviour_var('_triesleft'), $this->qa);
 106     }
 107
 108     public function get_expected_data() {
 109         if ($this->is_try_again_state()) {
 110             return array(
 111                 'tryagain' => PARAM_BOOL,
 112             );
 113         } else if ($this->qa->get_state()->is_active()) {
 114             return array(
 115                 'submit' => PARAM_BOOL,
 116             );
 117         }
 118         return parent::get_expected_data();
 119     }
 120
 121     public function get_expected_qt_data() {
 122         $hint = $this->get_applicable_hint();
 123         if (!empty($hint->clearwrong)) {
 124             return $this->question->get_expected_data();
 125         }
 126         return parent::get_expected_qt_data();
 127     }
 128
 129     public function get_state_string($showcorrectness) {
 130         $state = $this->qa->get_state();
 131         if (!$state->is_active() || $state == question_state::$invalid) {
 132             return parent::get_state_string($showcorrectness);
 133         }
 134
 135         if ($this->is_try_again_state()) {
 136             return get_string('notcomplete', 'qbehaviour_interactive');
 137         } else {
 138             return get_string('triesremaining', 'qbehaviour_interactive',
 139                     $this->qa->get_last_behaviour_var('_triesleft'));
 140         }
 141     }
 142
 143     public function init_first_step(question_attempt_step $step, $variant) {
 144         parent::init_first_step($step, $variant);
 145         $step->set_behaviour_var('_triesleft', count($this->question->hints) + 1);
 146     }
 147
 148     public function process_action(question_attempt_pending_step $pendingstep) {
 149         if ($pendingstep->has_behaviour_var('finish')) {
 150             return $this->process_finish($pendingstep);
 151         }
 152         if ($this->is_try_again_state()) {
 153             if ($pendingstep->has_behaviour_var('tryagain')) {
 154                 return $this->process_try_again($pendingstep);
 155             } else {
 156                 return question_attempt::DISCARD;
 157             }
 158         } else {
 159             if ($pendingstep->has_behaviour_var('comment')) {
 160                 return $this->process_comment($pendingstep);
 161             } else if ($pendingstep->has_behaviour_var('submit')) {
 162                 return $this->process_submit($pendingstep);
 163             } else {
 164                 return $this->process_save($pendingstep);
 165             }
 166         }
 167     }
 168
 169     public function summarise_action(question_attempt_step $step) {
 170         if ($step->has_behaviour_var('comment')) {
 171             return $this->summarise_manual_comment($step);
 172         } else if ($step->has_behaviour_var('finish')) {
 173             return $this->summarise_finish($step);
 174         } else if ($step->has_behaviour_var('tryagain')) {
 175             return get_string('tryagain', 'qbehaviour_interactive');
 176         } else if ($step->has_behaviour_var('submit')) {
 177             return $this->summarise_submit($step);
 178         } else {
 179             return $this->summarise_save($step);
 180         }
 181     }
 182
 183     public function process_try_again(question_attempt_pending_step $pendingstep) {
 184         $pendingstep->set_state(question_state::$todo);
 185         return question_attempt::KEEP;
 186     }
 187
 188     public function process_submit(question_attempt_pending_step $pendingstep) {
 189         if ($this->qa->get_state()->is_finished()) {
 190             return question_attempt::DISCARD;
 191         }
 192
 193         if (!$this->is_complete_response($pendingstep)) {
 194             $pendingstep->set_state(question_state::$invalid);
 195
 196         } else {
 197             $triesleft = $this->qa->get_last_behaviour_var('_triesleft');
 198             $response = $pendingstep->get_qt_data();
 199             list($fraction, $state) = $this->question->grade_response($response);
 200             if ($state == question_state::$gradedright || $triesleft == 1) {
 201                 $pendingstep->set_state($state);
 202                 $pendingstep->set_fraction($this->adjust_fraction($fraction, $pendingstep));
 203
 204             } else {
 205                 $pendingstep->set_behaviour_var('_triesleft', $triesleft - 1);
 206                 $pendingstep->set_state(question_state::$todo);
 207             }
 208             $pendingstep->set_new_response_summary($this->question->summarise_response($response));
 209         }
 210         return question_attempt::KEEP;
 211     }
 212
 213     protected function adjust_fraction($fraction, question_attempt_pending_step $pendingstep) {
 214         $totaltries = $this->qa->get_step(0)->get_behaviour_var('_triesleft');
 215         $triesleft = $this->qa->get_last_behaviour_var('_triesleft');
 216
 217         $fraction -= ($totaltries - $triesleft) * $this->question->penalty;
 218         $fraction = max($fraction, 0);
 219         return $fraction;
 220     }
 221
 222     public function process_finish(question_attempt_pending_step $pendingstep) {
 223         if ($this->qa->get_state()->is_finished()) {
 224             return question_attempt::DISCARD;
 225         }
 226
 227         $response = $this->qa->get_last_qt_data();
 228         if (!$this->question->is_gradable_response($response)) {
 229             $pendingstep->set_state(question_state::$gaveup);
 230
 231         } else {
 232             list($fraction, $state) = $this->question->grade_response($response);
 233             $pendingstep->set_fraction($this->adjust_fraction($fraction, $pendingstep));
 234             $pendingstep->set_state($state);
 235         }
 236         $pendingstep->set_new_response_summary($this->question->summarise_response($response));
 237         return question_attempt::KEEP;
 238     }
 239
 240     public function process_save(question_attempt_pending_step $pendingstep) {
 241         $status = parent::process_save($pendingstep);
 242         if ($status == question_attempt::KEEP &&
 243                 $pendingstep->get_state() == question_state::$complete) {
 244             $pendingstep->set_state(question_state::$todo);
 245         }
 246         return $status;
 247     }
 248 }