MDL-65399 mod_quiz: UI should prevent deleting the last slot of section

mod/quiz/classes/output/edit_renderer.php

@@ -1150,6 +1150,8 @@ protected function initialise_editing_javascript(structure $structure,
 
         $this->page->requires->strings_for_js(array(
                 'addpagebreak',
+                'cannotremoveallsectionslots',
+                'cannotremoveslots',
                 'confirmremovesectionheading',
                 'confirmremovequestion',
                 'dragtoafter',

mod/quiz/lang/en/quiz.php

@@ -137,6 +137,8 @@
 $string['cannotloadquestion'] = 'Could not load question options';
 $string['cannotloadtypeinfo'] = 'Unable to load questiontype specific question information';
 $string['cannotopen'] = 'Cannot open export file ({$a})';
+$string['cannotremoveallsectionslots'] = 'You have selected all questions of the \'{$a}\' section heading. It is not allowed to remove all questions under a section heading.';
+$string['cannotremoveslots'] = 'Can not remove questions';
 $string['cannotrestore'] = 'Could not restore question sessions';
 $string['cannotreviewopen'] = 'You cannot review this attempt, it is still open.';
 $string['cannotsavelayout'] = 'Could not save layout';

mod/quiz/styles.css

@@ -1190,11 +1190,9 @@ table#categoryquestions {
     display: none;
 }
 
-#page-mod-quiz-edit.select-multiple .mod-quiz-edit-content .section-heading,
+#page-mod-quiz-edit.select-multiple .mod-quiz-edit-content .section-heading a,
 #page-mod-quiz-edit.select-multiple .mod-quiz-edit-content .section-heading form,
-#page-mod-quiz-edit.select-multiple .mod-quiz-edit-content .section-heading .instancesectioncontainer,
-#page-mod-quiz-edit.select-multiple .mod-quiz-edit-content .section-heading .instanceshufflequestions,
-#page-mod-quiz-edit.select-multiple .mod-quiz-edit-content .section-heading .instancesectioncontainer h3 {
+#page-mod-quiz-edit.select-multiple .mod-quiz-edit-content .section-heading .instanceshufflequestions {
     display: none;
 }
 

mod/quiz/tests/behat/editing_remove_multiple_questions.feature

@@ -167,3 +167,74 @@ Feature: Edit quiz page - remove multiple questions
 
     When I click on "Deselect all" "link"
     Then the field "selectquestion-3" matches value "0"
+
+  @javascript
+  Scenario: Delete multiple questions from sections
+    Given the following "questions" exist:
+      | questioncategory | qtype       | name       | questiontext    |
+      | Test questions   | truefalse   | Question A | First question  |
+      | Test questions   | truefalse   | Question B | Second question |
+      | Test questions   | truefalse   | Question C | Third question  |
+      | Test questions   | truefalse   | Question D | Fourth question |
+      | Test questions   | truefalse   | Question E | Fifth question  |
+      | Test questions   | truefalse   | Question F | Sixth question  |
+    And quiz "Quiz 1" contains the following questions:
+      | question   | page |
+      | Question A | 1    |
+      | Question B | 2    |
+      | Question C | 3    |
+      | Question D | 4    |
+      | Question E | 5    |
+      | Question F | 6    |
+    And quiz "Quiz 1" contains the following sections:
+      | heading   | firstslot | shuffle |
+      | Section 1 | 1         | 0       |
+      | Section 2 | 2         | 0       |
+      | Section 3 | 4         | 0       |
+    And I navigate to "Edit quiz" in current page administration
+
+    When I click on "Select multiple items" "button"
+    And I click on "selectquestion-3" "checkbox"
+    And I click on "selectquestion-5" "checkbox"
+    And I click on "selectquestion-6" "checkbox"
+    And I click on "Delete selected" "button"
+    And I click on "Yes" "button" in the "Confirm" "dialogue"
+
+    Then I should see "Question A" on quiz page "1"
+    And I should see "Question B" on quiz page "2"
+    And I should see "Question D" on quiz page "3"
+    And I should not see "Question C"
+    And I should not see "Question E"
+    And I should not see "Question F"
+
+  @javascript
+  Scenario: Attempting to delete all questions of a sections
+    Given the following "questions" exist:
+      | questioncategory | qtype       | name       | questiontext    |
+      | Test questions   | truefalse   | Question A | First question  |
+      | Test questions   | truefalse   | Question B | Second question |
+      | Test questions   | truefalse   | Question C | Third question  |
+      | Test questions   | truefalse   | Question D | Fourth question |
+      | Test questions   | truefalse   | Question E | Fifth question  |
+      | Test questions   | truefalse   | Question F | Sixth question  |
+    And quiz "Quiz 1" contains the following questions:
+      | question   | page |
+      | Question A | 1    |
+      | Question B | 2    |
+      | Question C | 3    |
+      | Question D | 4    |
+      | Question E | 5    |
+      | Question F | 6    |
+    And quiz "Quiz 1" contains the following sections:
+      | heading   | firstslot | shuffle |
+      | Section 1 | 1         | 0       |
+      | Section 2 | 2         | 0       |
+      | Section 3 | 4         | 0       |
+    And I navigate to "Edit quiz" in current page administration
+
+    When I click on "Select multiple items" "button"
+    And I click on "selectquestion-2" "checkbox"
+    And I click on "selectquestion-3" "checkbox"
+    And I click on "Delete selected" "button"
+
+    Then I should see "Can not remove questions"

mod/quiz/yui/build/moodle-mod_quiz-toolboxes/moodle-mod_quiz-toolboxes-debug.js

@@ -64,6 +64,7 @@ var CSS = {
         NUMQUESTIONS: '.numberofquestions',
         PAGECONTENT: 'div#page-content',
         PAGELI: 'li.page',
+        SECTIONLI: 'li.section',
         SECTIONUL: 'ul.section',
         SECTIONFORM: '.instancesectioncontainer form',
         SECTIONINPUT: 'input[name=section]',
@@ -337,7 +338,7 @@ Y.extend(RESOURCETOOLBOX, TOOLBOX, {
         Y.one(SELECTOR.SELECTMULTIPLEDELETEBUTTON).setAttribute('disabled', 'disabled');
 
         // Assign the delete method to the delete multiple button.
-        Y.delegate('click', this.delete_multiple_with_confirmation, BODY, SELECTOR.SELECTMULTIPLEDELETEBUTTON, this);
+        Y.delegate('click', this.delete_multiple_action, BODY, SELECTOR.SELECTMULTIPLEDELETEBUTTON, this);
 
         // Enable the delete all button only when at least one slot is selected.
         Y.delegate('click', this.toggle_select_all_buttons_enabled, BODY, SELECTOR.SELECTMULTIPLECHECKBOX, this);
@@ -439,7 +440,6 @@ Y.extend(RESOURCETOOLBOX, TOOLBOX, {
      * @param {EventFacade} ev The event that was fired.
      * @param {Node} button The button that triggered this action.
      * @param {Node} activity The activity node that this action will be performed on.
-     * @chainable
      */
     delete_with_confirmation: function(ev, button, activity) {
         // Prevent the default button action.
@@ -481,13 +481,62 @@ Y.extend(RESOURCETOOLBOX, TOOLBOX, {
         }, this);
     },
 
+    /**
+     * Finds the section that would become empty if we remove the selected slots.
+     *
+     * @protected
+     * @method find_sections_that_would_become_empty
+     * @returns {String} The name of the first section found
+     */
+    find_sections_that_would_become_empty: function() {
+        var section;
+        var sectionnodes = Y.all(SELECTOR.SECTIONLI);
+
+        if (sectionnodes.size() > 1) {
+            sectionnodes.some(function(node) {
+                var sectionname = node.one(SELECTOR.INSTANCESECTION).getContent();
+                var checked = node.all(SELECTOR.SELECTMULTIPLECHECKBOX + ':checked');
+                var unchecked = node.all(SELECTOR.SELECTMULTIPLECHECKBOX + ':not(:checked)');
+
+                if (!checked.isEmpty() && unchecked.isEmpty()) {
+                    section = sectionname;
+                }
+
+                return section;
+            });
+        }
+
+        return section;
+    },
+
+    /**
+     * Takes care of what needs to happen when the user clicks on the delete multiple button.
+     *
+     * @protected
+     * @method delete_multiple_action
+     * @param {EventFacade} ev The event that was fired.
+     */
+    delete_multiple_action: function(ev) {
+        var problemsection = this.find_sections_that_would_become_empty();
+
+        if (problemsection) {
+            var alert = new M.core.alert({
+                title: M.util.get_string('cannotremoveslots', 'quiz'),
+                message: M.util.get_string('cannotremoveallsectionslots', 'quiz', problemsection)
+            });
+
+            alert.show();
+        } else {
+            this.delete_multiple_with_confirmation(ev);
+        }
+    },
+
     /**
      * Deletes the given activities or resources after confirmation.
      *
      * @protected
      * @method delete_multiple_with_confirmation
      * @param {EventFacade} ev The event that was fired.
-     * @chainable
      */
     delete_multiple_with_confirmation: function(ev) {
         ev.preventDefault();