From f6a778497e29e2828bdd73600209f8e7ea07bbde Mon Sep 17 00:00:00 2001
From: Simey Lameze <simey@moodle.com>
Date: Thu, 4 Apr 2019 10:43:14 +0800
Subject: [PATCH 1/5] MDL-5311 qtype_multichoice: add clear my choice option

---
 .../multichoice/amd/build/clearchoice.min.js  |   1 +
 .../type/multichoice/amd/src/clearchoice.js   | 105 ++++++++++++++++++
 .../multichoice/lang/en/qtype_multichoice.php |   1 +
 question/type/multichoice/question.php        |  15 ++-
 question/type/multichoice/renderer.php        |  64 +++++++++++
 5 files changed, 181 insertions(+), 5 deletions(-)
 create mode 100644 question/type/multichoice/amd/build/clearchoice.min.js
 create mode 100644 question/type/multichoice/amd/src/clearchoice.js

diff --git a/question/type/multichoice/amd/build/clearchoice.min.js b/question/type/multichoice/amd/build/clearchoice.min.js
new file mode 100644
index 00000000000..dc8c9fbc04f
--- /dev/null
+++ b/question/type/multichoice/amd/build/clearchoice.min.js
@@ -0,0 +1 @@
+define(["jquery","core/custom_interaction_events"],function(a,b){var c={CHOICE_ELEMENT:".answer input",CLEAR_CHOICE_ELEMENT:'div[class="qtype_multichoice_clearchoice"]'},d=function(a){a.find('input[type="radio"]').prop("checked",!0)},e=function(a,b){return a.find('div[id="'+b+'"]')},f=function(a){a.addClass("hidden")},g=function(a){a.removeClass("hidden")},h=function(a,h){var i=e(a,h);a.on(b.events.activate,c.CLEAR_CHOICE_ELEMENT,function(){d(i),f(i)}),a.on(b.events.activate,c.CHOICE_ELEMENT,function(){g(i)})},i=function(b,c){b=a("#"+b),h(b,c)};return{init:i}});
\ No newline at end of file
diff --git a/question/type/multichoice/amd/src/clearchoice.js b/question/type/multichoice/amd/src/clearchoice.js
new file mode 100644
index 00000000000..59a03e62ae6
--- /dev/null
+++ b/question/type/multichoice/amd/src/clearchoice.js
@@ -0,0 +1,105 @@
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle 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 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle 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.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Manages 'Clear my choice' functionality actions.
+ *
+ * @module     qtype_multichoice/clearchoice
+ * @copyright  2019 Simey Lameze <simey@moodle.com>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @since      3.7
+ */
+define(['jquery', 'core/custom_interaction_events'], function($, CustomEvents) {
+
+    var SELECTORS = {
+        CHOICE_ELEMENT: '.answer input',
+        CLEAR_CHOICE_ELEMENT: 'div[class="qtype_multichoice_clearchoice"]'
+    };
+
+    /**
+     * Mark clear choice radio as checked.
+     *
+     * @param {Object} clearChoiceContainer The clear choice option container.
+     */
+    var checkClearChoiceRadio = function(clearChoiceContainer) {
+        clearChoiceContainer.find('input[type="radio"]').prop('checked', true);
+    };
+
+    /**
+     * Get the clear choice div container.
+     *
+     * @param {Object} root The question root element.
+     * @param {string} fieldPrefix The question outer div prefix.
+     * @returns {Object} The clear choice div container.
+     */
+    var getClearChoiceElement = function(root, fieldPrefix) {
+        return root.find('div[id="' + fieldPrefix + '"]');
+    };
+
+    /**
+     * Hide clear choice option.
+     *
+     * @param {Object} clearChoiceContainer The clear choice option container.
+     */
+    var hideClearChoiceOption = function(clearChoiceContainer) {
+        clearChoiceContainer.addClass('hidden');
+    };
+
+    /**
+     * Shows clear choice option.
+     *
+     * @param {Object} clearChoiceContainer The clear choice option container.
+     */
+    var showClearChoiceOption = function(clearChoiceContainer) {
+        clearChoiceContainer.removeClass('hidden');
+    };
+
+    /**
+     * Register event listeners for the clear choice module.
+     *
+     * @param {Object} root The question outer div prefix.
+     * @param {string} fieldPrefix The "Clear choice" div prefix.
+     */
+    var registerEventListeners = function(root, fieldPrefix) {
+        var clearChoiceContainer = getClearChoiceElement(root, fieldPrefix);
+
+        root.on(CustomEvents.events.activate, SELECTORS.CLEAR_CHOICE_ELEMENT, function() {
+                // Mark the clear choice radio element as checked.
+                checkClearChoiceRadio(clearChoiceContainer);
+                // Now that the hidden radio has been checked, hide the clear choice option.
+                hideClearChoiceOption(clearChoiceContainer);
+        });
+
+        root.on(CustomEvents.events.activate, SELECTORS.CHOICE_ELEMENT, function() {
+            // If the event has been triggered by any other choice, show the clear choice option.
+            showClearChoiceOption(clearChoiceContainer);
+        });
+    };
+
+    /**
+     * Initialise clear choice module.
+
+     * @param {string} root The question outer div prefix.
+     * @param {string} fieldPrefix The "Clear choice" div prefix.
+     */
+    var init = function(root, fieldPrefix) {
+        root = $('#' + root);
+        registerEventListeners(root, fieldPrefix);
+    };
+
+    return {
+        init: init
+    };
+});
diff --git a/question/type/multichoice/lang/en/qtype_multichoice.php b/question/type/multichoice/lang/en/qtype_multichoice.php
index 9e4ebb819fa..2473d43384d 100644
--- a/question/type/multichoice/lang/en/qtype_multichoice.php
+++ b/question/type/multichoice/lang/en/qtype_multichoice.php
@@ -37,6 +37,7 @@ $string['answersingleno'] = 'Multiple answers allowed';
 $string['answersingleyes'] = 'One answer only';
 $string['choiceno'] = 'Choice {$a}';
 $string['choices'] = 'Available choices';
+$string['clearchoice'] = 'Clear my choice';
 $string['clozeaid'] = 'Enter missing word';
 $string['correctansweris'] = 'The correct answer is: {$a}';
 $string['correctanswersare'] = 'The correct answers are: {$a}';
diff --git a/question/type/multichoice/question.php b/question/type/multichoice/question.php
index 09b949355c4..fcf63c5f9da 100644
--- a/question/type/multichoice/question.php
+++ b/question/type/multichoice/question.php
@@ -176,8 +176,7 @@ class qtype_multichoice_single_question extends qtype_multichoice_base {
     }
 
     public function summarise_response(array $response) {
-        if (!array_key_exists('answer', $response) ||
-                !array_key_exists($response['answer'], $this->order)) {
+        if (!$this->is_complete_response($response)) {
             return null;
         }
         $ansid = $this->order[$response['answer']];
@@ -186,8 +185,7 @@ class qtype_multichoice_single_question extends qtype_multichoice_base {
     }
 
     public function classify_response(array $response) {
-        if (!array_key_exists('answer', $response) ||
-                !array_key_exists($response['answer'], $this->order)) {
+        if (!$this->is_complete_response($response)) {
             return array($this->id => question_classified_response::no_response());
         }
         $choiceid = $this->order[$response['answer']];
@@ -230,11 +228,18 @@ class qtype_multichoice_single_question extends qtype_multichoice_base {
     }
 
     public function is_same_response(array $prevresponse, array $newresponse) {
+        if (!$this->is_complete_response($prevresponse)) {
+            $prevresponse = [];
+        }
+        if (!$this->is_complete_response($newresponse)) {
+            $newresponse = [];
+        }
         return question_utils::arrays_same_at_key($prevresponse, $newresponse, 'answer');
     }
 
     public function is_complete_response(array $response) {
-        return array_key_exists('answer', $response) && $response['answer'] !== '';
+        return array_key_exists('answer', $response) && $response['answer'] !== ''
+                && (string) $response['answer'] !== '-1';
     }
 
     public function is_gradable_response(array $response) {
diff --git a/question/type/multichoice/renderer.php b/question/type/multichoice/renderer.php
index 25a5b2e40bb..b48809af67b 100644
--- a/question/type/multichoice/renderer.php
+++ b/question/type/multichoice/renderer.php
@@ -35,6 +35,17 @@ defined('MOODLE_INTERNAL') || die();
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 abstract class qtype_multichoice_renderer_base extends qtype_with_combined_feedback_renderer {
+
+    /**
+     * Method to generating the bits of output after question choices.
+     *
+     * @param question_attempt $qa The question attempt object.
+     * @param question_display_options $options controls what should and should not be displayed.
+     *
+     * @return string HTML output.
+     */
+    protected abstract function after_choices(question_attempt $qa, question_display_options $options);
+
     protected abstract function get_input_type();
 
     protected abstract function get_input_name(question_attempt $qa, $value);
@@ -136,6 +147,8 @@ abstract class qtype_multichoice_renderer_base extends qtype_with_combined_feedb
         }
         $result .= html_writer::end_tag('div'); // Answer.
 
+        $result .= $this->after_choices($qa, $options);
+
         $result .= html_writer::end_tag('div'); // Ablock.
 
         if ($qa->get_state() == question_state::$invalid) {
@@ -252,6 +265,53 @@ class qtype_multichoice_single_renderer extends qtype_multichoice_renderer_base
         }
         return $this->correct_choices($right);
     }
+
+    public function after_choices(question_attempt $qa, question_display_options $options) {
+        // Only load the clear choice feature if it's not read only.
+        if ($options->readonly) {
+            return '';
+        }
+
+        $question = $qa->get_question();
+        $response = $question->get_response($qa);
+        $hascheckedchoice = false;
+        foreach ($question->get_order($qa) as $value => $ansid) {
+            if ($question->is_choice_selected($response, $value)) {
+                $hascheckedchoice = true;
+                break;
+            }
+        }
+
+        $clearchoiceid = $this->get_input_id($qa, -1);
+        $clearchoicefieldname = $qa->get_qt_field_name('clearchoice');
+        $clearchoiceradioattrs = [
+            'type' => $this->get_input_type(),
+            'name' => $qa->get_qt_field_name('answer'),
+            'id' => $clearchoiceid,
+            'value' => -1
+        ];
+
+        $cssclass = 'qtype_multichoice_clearchoice';
+        // When no choice selected during rendering, then hide the clear choice option.
+        if (!$hascheckedchoice && $response == -1) {
+            $cssclass .= ' hidden';
+            $clearchoiceradioattrs['checked'] = 'checked';
+        }
+        // Adds an hidden radio that will be checked to give the impression the choice has been cleared.
+        $clearchoiceradio = html_writer::empty_tag('input', $clearchoiceradioattrs);
+        $clearchoiceradio .= html_writer::tag('label', get_string('clearchoice', 'qtype_multichoice'),
+            ['for' => $clearchoiceid, 'role' => 'button', 'tabindex' => 0]);
+
+        // Now wrap the radio and label inside a div.
+        $result = html_writer::tag('div', $clearchoiceradio, ['id' => $clearchoicefieldname, 'class' => $cssclass]);
+
+        // Load required clearchoice AMD module.
+        $this->page->requires->js_call_amd('qtype_multichoice/clearchoice', 'init',
+            [$qa->get_outer_question_div_unique_id(), $clearchoicefieldname]);
+
+        return $result;
+    }
+
 }
 
 /**
@@ -262,6 +322,10 @@ class qtype_multichoice_single_renderer extends qtype_multichoice_renderer_base
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class qtype_multichoice_multi_renderer extends qtype_multichoice_renderer_base {
+    protected function after_choices(question_attempt $qa, question_display_options $options) {
+        return '';
+    }
+
     protected function get_input_type() {
         return 'checkbox';
     }

From 3c1717bb098c12ef6ae00211663b47f2b8aa3d9f Mon Sep 17 00:00:00 2001
From: Simey Lameze <simey@moodle.com>
Date: Thu, 4 Apr 2019 10:44:34 +0800
Subject: [PATCH 2/5] MDL-5311 qtype_multichoice: add a bit of styling to the
 option

---
 question/type/multichoice/styles.css  |  4 ++++
 theme/boost/scss/moodle/question.scss | 11 +++++++++++
 theme/boost/style/moodle.css          | 10 ++++++++++
 theme/classic/style/moodle.css        | 10 ++++++++++
 4 files changed, 35 insertions(+)

diff --git a/question/type/multichoice/styles.css b/question/type/multichoice/styles.css
index 5707361ec0b..77b4968b897 100644
--- a/question/type/multichoice/styles.css
+++ b/question/type/multichoice/styles.css
@@ -26,6 +26,10 @@
     width: 15px;
 }
 
+.qtype_multichoice_clearchoice input {
+    display: none;
+}
+
 /* Editing form. */
 body#page-question-type-multichoice div[id^=fitem_id_][id*=answer_] {
     background: #eee;
diff --git a/theme/boost/scss/moodle/question.scss b/theme/boost/scss/moodle/question.scss
index e3339389b54..e12fe7a96fe 100644
--- a/theme/boost/scss/moodle/question.scss
+++ b/theme/boost/scss/moodle/question.scss
@@ -310,6 +310,17 @@ body.path-question-type {
 .que.multichoice .answer div.r1 .icon.fa-remove {
     text-indent: 0;
 }
+.qtype_multichoice_clearchoice {
+    padding-top: 10px;
+    label {
+        cursor: pointer;
+        text-decoration: underline;
+        padding-left: 30px;
+    }
+}
+.qtype_multichoice_clearchoice input {
+    display: none;
+}
 
 .formulation input[type="text"],
 .formulation select {
diff --git a/theme/boost/style/moodle.css b/theme/boost/style/moodle.css
index 0e6fadd3fce..332ea8c8cf6 100644
--- a/theme/boost/style/moodle.css
+++ b/theme/boost/style/moodle.css
@@ -14028,6 +14028,16 @@ body.path-question-type {
 .que.multichoice .answer div.r1 .icon.fa-remove {
   text-indent: 0; }
 
+.qtype_multichoice_clearchoice {
+  padding-top: 10px; }
+  .qtype_multichoice_clearchoice label {
+    cursor: pointer;
+    text-decoration: underline;
+    padding-left: 30px; }
+
+.qtype_multichoice_clearchoice input {
+  display: none; }
+
 .formulation input[type="text"],
 .formulation select {
   width: auto;
diff --git a/theme/classic/style/moodle.css b/theme/classic/style/moodle.css
index 64dbcba9904..8c5de0ea122 100644
--- a/theme/classic/style/moodle.css
+++ b/theme/classic/style/moodle.css
@@ -14279,6 +14279,16 @@ body.path-question-type {
 .que.multichoice .answer div.r1 .icon.fa-remove {
   text-indent: 0; }
 
+.qtype_multichoice_clearchoice {
+  padding-top: 10px; }
+  .qtype_multichoice_clearchoice label {
+    cursor: pointer;
+    text-decoration: underline;
+    padding-left: 30px; }
+
+.qtype_multichoice_clearchoice input {
+  display: none; }
+
 .formulation input[type="text"],
 .formulation select {
   width: auto;

From 1ff39876006b96992f6fcd0e30edc1303c165aab Mon Sep 17 00:00:00 2001
From: Simey Lameze <simey@moodle.com>
Date: Thu, 4 Apr 2019 10:45:18 +0800
Subject: [PATCH 3/5] MDL-5311 qtype_multichoice: add behat scenario to
 question preview

---
 .../type/multichoice/tests/behat/preview.feature     | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/question/type/multichoice/tests/behat/preview.feature b/question/type/multichoice/tests/behat/preview.feature
index ed50c9f05e5..19e3e797c18 100644
--- a/question/type/multichoice/tests/behat/preview.feature
+++ b/question/type/multichoice/tests/behat/preview.feature
@@ -70,3 +70,15 @@ Feature: Preview a Multiple choice question
     And I should see "Well done!"
     And I should see "The correct answer is: One"
     And I switch to the main window
+
+  @javascript @_switch_window
+  Scenario: Preview a multiple choice question (single response) and clear a previous selected option.
+    When I click on "Preview" "link" in the "Multi-choice-002" "table_row"
+    And I switch to "questionpreview" window
+    And I set the field "How questions behave" to "Immediate feedback"
+    And I press "Start again with these options"
+    And I click on "One" "radio"
+    Then I should see "Clear my choice"
+    And I click on "Clear my choice" "text"
+    And I should not see "Clear my choice"
+    And I switch to the main window

From 9064f17bbc15a7a8e7ab7b61e72db9d9a685c58a Mon Sep 17 00:00:00 2001
From: Simey Lameze <simey@moodle.com>
Date: Thu, 4 Apr 2019 10:45:50 +0800
Subject: [PATCH 4/5] MDL-5311 qtype_multichoice: add php unit tests for the
 new option

---
 .../multichoice/tests/question_multi_test.php | 11 +++
 .../tests/question_single_test.php            | 28 +++++++-
 .../multichoice/tests/walkthrough_test.php    | 69 +++++++++++++++++++
 3 files changed, 107 insertions(+), 1 deletion(-)

diff --git a/question/type/multichoice/tests/question_multi_test.php b/question/type/multichoice/tests/question_multi_test.php
index fa3775d123a..1e5f56bc452 100644
--- a/question/type/multichoice/tests/question_multi_test.php
+++ b/question/type/multichoice/tests/question_multi_test.php
@@ -133,6 +133,17 @@ class qtype_multichoice_multi_question_test extends advanced_testcase {
         $this->assertEquals('B; C', $summary);
     }
 
+    public function test_summarise_response_clearchoice() {
+        $mc = test_question_maker::make_a_multichoice_multi_question();
+        $mc->shuffleanswers = false;
+        $mc->start_attempt(new question_attempt_step(), 1);
+
+        $summary = $mc->summarise_response($mc->prepare_simulated_post_data(array('clearchoice' => -1)),
+            test_question_maker::get_a_qa($mc));
+
+        $this->assertNull($summary);
+    }
+
     public function test_classify_response() {
         $mc = test_question_maker::make_a_multichoice_multi_question();
         $mc->start_attempt(new question_attempt_step(), 1);
diff --git a/question/type/multichoice/tests/question_single_test.php b/question/type/multichoice/tests/question_single_test.php
index 7b6b6b19238..f5f10a48df6 100644
--- a/question/type/multichoice/tests/question_single_test.php
+++ b/question/type/multichoice/tests/question_single_test.php
@@ -47,6 +47,8 @@ class qtype_multichoice_single_question_test extends advanced_testcase {
         $this->assertFalse($question->is_complete_response(array()));
         $this->assertTrue($question->is_complete_response(array('answer' => '0')));
         $this->assertTrue($question->is_complete_response(array('answer' => '2')));
+        $this->assertFalse($question->is_complete_response(array('answer' => '-1')));
+        $this->assertFalse($question->is_complete_response(array('answer' => -1)));
     }
 
     public function test_is_gradable_response() {
@@ -55,6 +57,7 @@ class qtype_multichoice_single_question_test extends advanced_testcase {
         $this->assertFalse($question->is_gradable_response(array()));
         $this->assertTrue($question->is_gradable_response(array('answer' => '0')));
         $this->assertTrue($question->is_gradable_response(array('answer' => '2')));
+        $this->assertFalse($question->is_gradable_response(array('answer' => '-1')));
     }
 
     public function test_is_same_response() {
@@ -80,6 +83,22 @@ class qtype_multichoice_single_question_test extends advanced_testcase {
         $this->assertTrue($question->is_same_response(
                 array('answer' => '2'),
                 array('answer' => '2')));
+
+        $this->assertFalse($question->is_same_response(
+                array('answer' => '0'),
+                array('answer' => '-1')));
+
+        $this->assertFalse($question->is_same_response(
+                array('answer' => '-1'),
+                array('answer' => '0')));
+
+        $this->assertTrue($question->is_same_response(
+                array('answer' => '-1'),
+                array('answer' => '-1')));
+
+        $this->assertTrue($question->is_same_response(
+                array(),
+                array('answer' => '-1')));
     }
 
     public function test_grading() {
@@ -138,6 +157,9 @@ class qtype_multichoice_single_question_test extends advanced_testcase {
                                             test_question_maker::get_a_qa($mc));
 
         $this->assertEquals('A', $summary);
+
+        $this->assertNull($mc->summarise_response(array(), test_question_maker::get_a_qa($mc)));
+        $this->assertNull($mc->summarise_response(array('answer' => '-1'), test_question_maker::get_a_qa($mc)));
     }
 
     public function test_classify_response() {
@@ -149,7 +171,11 @@ class qtype_multichoice_single_question_test extends advanced_testcase {
 
         $this->assertEquals(array(
                 $mc->id => question_classified_response::no_response(),
-            ), $mc->classify_response(array()));
+        ), $mc->classify_response(array()));
+
+        $this->assertEquals(array(
+                $mc->id => question_classified_response::no_response(),
+        ), $mc->classify_response(array('answer' => '-1')));
     }
 
     public function test_make_html_inline() {
diff --git a/question/type/multichoice/tests/walkthrough_test.php b/question/type/multichoice/tests/walkthrough_test.php
index 9eb2be43b97..37bc62f630b 100644
--- a/question/type/multichoice/tests/walkthrough_test.php
+++ b/question/type/multichoice/tests/walkthrough_test.php
@@ -97,4 +97,73 @@ class qtype_multichoice_walkthrough_test extends qbehaviour_walkthrough_test_bas
                 new question_pattern_expectation('/class="r0 correct"/'),
                 new question_pattern_expectation('/class="r1"/'));
     }
+
+    /**
+     * Test for clear choice option.
+     */
+    public function test_deferredfeedback_feedback_multichoice_clearchoice() {
+
+        // Create a multichoice, single question.
+        $mc = test_question_maker::make_a_multichoice_single_question();
+        $mc->shuffleanswers = false;
+
+        $clearchoice = -1;
+        $rightchoice = 0;
+        $wrongchoice = 2;
+
+        $this->start_attempt_at_question($mc, 'deferredfeedback', 3);
+
+        // Let's first submit the wrong choice (2).
+        $this->process_submission(array('answer' => $wrongchoice));  // Wrong choice (2).
+
+        $this->check_current_mark(null);
+        // Clear choice radio should not be checked.
+        $this->check_current_output(
+            $this->get_contains_mc_radio_expectation($rightchoice, true, false), // Not checked.
+            $this->get_contains_mc_radio_expectation($rightchoice + 1, true, false), // Not checked.
+            $this->get_contains_mc_radio_expectation($rightchoice + 2, true, true), // Wrong choice (2) checked.
+            $this->get_contains_mc_radio_expectation($clearchoice, true, false), // Not checked.
+            $this->get_does_not_contain_correctness_expectation(),
+            $this->get_does_not_contain_feedback_expectation()
+        );
+
+        // Now, let's clear our previous choice.
+        $this->process_submission(array('answer' => $clearchoice)); // Clear choice (-1).
+        $this->check_current_mark(null);
+
+        // This time, the clear choice radio should be the only one checked.
+        $this->check_current_output(
+            $this->get_contains_mc_radio_expectation($rightchoice, true, false), // Not checked.
+            $this->get_contains_mc_radio_expectation($rightchoice + 1, true, false), // Not checked.
+            $this->get_contains_mc_radio_expectation($rightchoice + 2, true, false), // Not checked.
+            $this->get_contains_mc_radio_expectation($clearchoice, true, true), // Clear choice radio checked.
+            $this->get_does_not_contain_correctness_expectation(),
+            $this->get_does_not_contain_feedback_expectation()
+        );
+
+        // Finally, let's submit the right choice.
+        $this->process_submission(array('answer' => $rightchoice)); // Right choice (0).
+        $this->check_current_state(question_state::$complete);
+        $this->check_current_mark(null);
+        $this->check_current_output(
+            $this->get_contains_mc_radio_expectation($rightchoice, true, true),
+            $this->get_contains_mc_radio_expectation($rightchoice + 1, true, false),
+            $this->get_contains_mc_radio_expectation($rightchoice + 2, true, false),
+            $this->get_contains_mc_radio_expectation($clearchoice, true, false),
+            $this->get_does_not_contain_correctness_expectation(),
+            $this->get_does_not_contain_feedback_expectation()
+        );
+
+        // Finish the attempt.
+        $this->finish();
+
+        // Verify.
+        $this->check_current_state(question_state::$gradedright);
+        $this->check_current_mark(3);
+        $this->check_current_output(
+            $this->get_contains_mc_radio_expectation($rightchoice, false, true),
+            $this->get_contains_correct_expectation(),
+            new question_pattern_expectation('/class="r0 correct"/'),
+            new question_pattern_expectation('/class="r1"/'));
+    }
 }

From 2589dcea7b1e42bb52707b25ae7b8816115725c6 Mon Sep 17 00:00:00 2001
From: Simey Lameze <simey@moodle.com>
Date: Thu, 4 Apr 2019 13:46:02 +0800
Subject: [PATCH 5/5] MDL-5311 qtype_multichoice: make clear choice option
 accessible

Thanks to Damyon for the help with accessibility.
---
 question/type/multichoice/amd/build/clearchoice.min.js | 2 +-
 question/type/multichoice/amd/src/clearchoice.js       | 4 ++--
 question/type/multichoice/renderer.php                 | 7 ++++---
 question/type/multichoice/styles.css                   | 4 ----
 theme/boost/scss/moodle/question.scss                  | 3 ---
 theme/boost/style/moodle.css                           | 3 ---
 theme/classic/style/moodle.css                         | 3 ---
 7 files changed, 7 insertions(+), 19 deletions(-)

diff --git a/question/type/multichoice/amd/build/clearchoice.min.js b/question/type/multichoice/amd/build/clearchoice.min.js
index dc8c9fbc04f..3a002441f49 100644
--- a/question/type/multichoice/amd/build/clearchoice.min.js
+++ b/question/type/multichoice/amd/build/clearchoice.min.js
@@ -1 +1 @@
-define(["jquery","core/custom_interaction_events"],function(a,b){var c={CHOICE_ELEMENT:".answer input",CLEAR_CHOICE_ELEMENT:'div[class="qtype_multichoice_clearchoice"]'},d=function(a){a.find('input[type="radio"]').prop("checked",!0)},e=function(a,b){return a.find('div[id="'+b+'"]')},f=function(a){a.addClass("hidden")},g=function(a){a.removeClass("hidden")},h=function(a,h){var i=e(a,h);a.on(b.events.activate,c.CLEAR_CHOICE_ELEMENT,function(){d(i),f(i)}),a.on(b.events.activate,c.CHOICE_ELEMENT,function(){g(i)})},i=function(b,c){b=a("#"+b),h(b,c)};return{init:i}});
\ No newline at end of file
+define(["jquery","core/custom_interaction_events"],function(a,b){var c={CHOICE_ELEMENT:".answer input",CLEAR_CHOICE_ELEMENT:'div[class="qtype_multichoice_clearchoice"]'},d=function(a){a.find('input[type="radio"]').prop("checked",!0)},e=function(a,b){return a.find('div[id="'+b+'"]')},f=function(a){a.addClass("sr-only")},g=function(a){a.removeClass("sr-only")},h=function(a,h){var i=e(a,h);a.on(b.events.activate,c.CLEAR_CHOICE_ELEMENT,function(){d(i),f(i)}),a.on(b.events.activate,c.CHOICE_ELEMENT,function(){g(i)})},i=function(b,c){b=a("#"+b),h(b,c)};return{init:i}});
\ No newline at end of file
diff --git a/question/type/multichoice/amd/src/clearchoice.js b/question/type/multichoice/amd/src/clearchoice.js
index 59a03e62ae6..3c15efb7e34 100644
--- a/question/type/multichoice/amd/src/clearchoice.js
+++ b/question/type/multichoice/amd/src/clearchoice.js
@@ -54,7 +54,7 @@ define(['jquery', 'core/custom_interaction_events'], function($, CustomEvents) {
      * @param {Object} clearChoiceContainer The clear choice option container.
      */
     var hideClearChoiceOption = function(clearChoiceContainer) {
-        clearChoiceContainer.addClass('hidden');
+        clearChoiceContainer.addClass('sr-only');
     };
 
     /**
@@ -63,7 +63,7 @@ define(['jquery', 'core/custom_interaction_events'], function($, CustomEvents) {
      * @param {Object} clearChoiceContainer The clear choice option container.
      */
     var showClearChoiceOption = function(clearChoiceContainer) {
-        clearChoiceContainer.removeClass('hidden');
+        clearChoiceContainer.removeClass('sr-only');
     };
 
     /**
diff --git a/question/type/multichoice/renderer.php b/question/type/multichoice/renderer.php
index b48809af67b..61585b41e55 100644
--- a/question/type/multichoice/renderer.php
+++ b/question/type/multichoice/renderer.php
@@ -288,19 +288,20 @@ class qtype_multichoice_single_renderer extends qtype_multichoice_renderer_base
             'type' => $this->get_input_type(),
             'name' => $qa->get_qt_field_name('answer'),
             'id' => $clearchoiceid,
-            'value' => -1
+            'value' => -1,
+            'class' => 'sr-only'
         ];
 
         $cssclass = 'qtype_multichoice_clearchoice';
         // When no choice selected during rendering, then hide the clear choice option.
         if (!$hascheckedchoice && $response == -1) {
-            $cssclass .= ' hidden';
+            $cssclass .= ' sr-only';
             $clearchoiceradioattrs['checked'] = 'checked';
         }
         // Adds an hidden radio that will be checked to give the impression the choice has been cleared.
         $clearchoiceradio = html_writer::empty_tag('input', $clearchoiceradioattrs);
         $clearchoiceradio .= html_writer::tag('label', get_string('clearchoice', 'qtype_multichoice'),
-            ['for' => $clearchoiceid, 'role' => 'button', 'tabindex' => 0]);
+            ['for' => $clearchoiceid]);
 
         // Now wrap the radio and label inside a div.
         $result = html_writer::tag('div', $clearchoiceradio, ['id' => $clearchoicefieldname, 'class' => $cssclass]);
diff --git a/question/type/multichoice/styles.css b/question/type/multichoice/styles.css
index 77b4968b897..5707361ec0b 100644
--- a/question/type/multichoice/styles.css
+++ b/question/type/multichoice/styles.css
@@ -26,10 +26,6 @@
     width: 15px;
 }
 
-.qtype_multichoice_clearchoice input {
-    display: none;
-}
-
 /* Editing form. */
 body#page-question-type-multichoice div[id^=fitem_id_][id*=answer_] {
     background: #eee;
diff --git a/theme/boost/scss/moodle/question.scss b/theme/boost/scss/moodle/question.scss
index e12fe7a96fe..786c7f1a2a5 100644
--- a/theme/boost/scss/moodle/question.scss
+++ b/theme/boost/scss/moodle/question.scss
@@ -318,9 +318,6 @@ body.path-question-type {
         padding-left: 30px;
     }
 }
-.qtype_multichoice_clearchoice input {
-    display: none;
-}
 
 .formulation input[type="text"],
 .formulation select {
diff --git a/theme/boost/style/moodle.css b/theme/boost/style/moodle.css
index 332ea8c8cf6..f24e0baabf0 100644
--- a/theme/boost/style/moodle.css
+++ b/theme/boost/style/moodle.css
@@ -14035,9 +14035,6 @@ body.path-question-type {
     text-decoration: underline;
     padding-left: 30px; }
 
-.qtype_multichoice_clearchoice input {
-  display: none; }
-
 .formulation input[type="text"],
 .formulation select {
   width: auto;
diff --git a/theme/classic/style/moodle.css b/theme/classic/style/moodle.css
index 8c5de0ea122..15e39d64ae8 100644
--- a/theme/classic/style/moodle.css
+++ b/theme/classic/style/moodle.css
@@ -14286,9 +14286,6 @@ body.path-question-type {
     text-decoration: underline;
     padding-left: 30px; }
 
-.qtype_multichoice_clearchoice input {
-  display: none; }
-
 .formulation input[type="text"],
 .formulation select {
   width: auto;