MDL-64901 block_myoverview: admin settings to control available layouts

Added an admin setting which allows the administrator to set the available layouts for users and which
defaults to all layouts being available, or the card layout only if no layouts are enabled.
If only one layout is enabled, the dropdown `nav-display-selector` template will not be displayed as
it can no longer be utilised.
If the user preference is set to a layout that is no longer available, this is ignored and the first
available layout defaulted to.

Author: Tom Dickman

blocks/myoverview/amd/build/view.min.js

@@ -363,7 +363,7 @@ function(
         var filters = getFilterValues(root);
 
         var currentTemplate = '';
-        if (filters.display == 'cards') {
+        if (filters.display == 'card') {
             currentTemplate = TEMPLATES.COURSES_CARDS;
         } else if (filters.display == 'list') {
             currentTemplate = TEMPLATES.COURSES_LIST;

blocks/myoverview/amd/src/view.js

@@ -74,7 +74,7 @@ public function applicable_formats() {
     }
 
     /**
-     * Allow the block to have a configuration page
+     * Allow the block to have a configuration page.
      *
      * @return boolean
      */

blocks/myoverview/block_myoverview.php

@@ -27,6 +27,7 @@
 use renderable;
 use renderer_base;
 use templatable;
+use stdClass;
 
 require_once($CFG->dirroot . '/blocks/myoverview/lib.php');
 
@@ -39,75 +40,139 @@
 class main implements renderable, templatable {
 
     /**
-     * Store the grouping preference
+     * Store the grouping preference.
      *
      * @var string String matching the grouping constants defined in myoverview/lib.php
      */
     private $grouping;
 
     /**
-     * Store the sort preference
+     * Store the sort preference.
      *
      * @var string String matching the sort constants defined in myoverview/lib.php
      */
     private $sort;
 
     /**
-     * Store the view preference
+     * Store the view preference.
      *
      * @var string String matching the view/display constants defined in myoverview/lib.php
      */
     private $view;
 
     /**
-     * Store the paging preference
+     * Store the paging preference.
      *
      * @var string String matching the paging constants defined in myoverview/lib.php
      */
     private $paging;
 
     /**
-     * Store the display categories config setting
+     * Store the display categories config setting.
      *
      * @var boolean
      */
     private $displaycategories;
 
+    /**
+     * Store the configuration values for the myoverview block.
+     *
+     * @var array Array of available layouts matching view/display constants defined in myoverview/lib.php
+     */
+    private $layouts;
+
     /**
      * main constructor.
      * Initialize the user preferences
      *
      * @param string $grouping Grouping user preference
      * @param string $sort Sort user preference
      * @param string $view Display user preference
+     *
+     * @throws \dml_exception
      */
     public function __construct($grouping, $sort, $view, $paging) {
         $this->grouping = $grouping ? $grouping : BLOCK_MYOVERVIEW_GROUPING_ALL;
         $this->sort = $sort ? $sort : BLOCK_MYOVERVIEW_SORTING_TITLE;
-        $this->view = $view ? $view : BLOCK_MYOVERVIEW_VIEW_CARD;
         $this->paging = $paging ? $paging : BLOCK_MYOVERVIEW_PAGING_12;
+
         $config = get_config('block_myoverview');
         if (!$config->displaycategories) {
             $this->displaycategories = BLOCK_MYOVERVIEW_DISPLAY_CATEGORIES_OFF;
         } else {
             $this->displaycategories = BLOCK_MYOVERVIEW_DISPLAY_CATEGORIES_ON;
         }
+
+        $this->set_available_layouts();
+        $this->view = $view ? $view : reset($this->layouts);
     }
 
+
     /**
-     * Get the user preferences as an array to figure out what has been selected
+     * Set the available layouts based on the config table settings,
+     * if none are available, defaults to the cards view.
+     *
+     * @throws \dml_exception
+     *
+     */
+    public function set_available_layouts() {
+
+        if ($config = get_config('block_myoverview', 'layouts')) {
+            $this->layouts = explode(',', $config);
+        } else {
+            $this->layouts = array(BLOCK_MYOVERVIEW_VIEW_CARD);
+        }
+    }
+
+    /**
+     * Get the user preferences as an array to figure out what has been selected.
      *
      * @return array $preferences Array with the pref as key and value set to true
      */
     public function get_preferences_as_booleans() {
         $preferences = [];
-        $preferences[$this->view] = true;
         $preferences[$this->sort] = true;
         $preferences[$this->grouping] = true;
+        // Only use the user view/display preference if it is in available layouts.
+        if (in_array($this->view, $this->layouts)) {
+            $preferences[$this->view] = true;
+        } else {
+            $preferences[reset($this->layouts)] = true;
+        }
 
         return $preferences;
     }
 
+    /**
+     * Format a layout into an object for export as a Context variable to template.
+     *
+     * @param string $layoutname
+     *
+     * @return \stdClass $layout an object representation of a layout
+     * @throws \coding_exception
+     */
+    public function format_layout_for_export($layoutname) {
+        $layout = new stdClass();
+
+        $layout->id = $layoutname;
+        $layout->name = get_string($layoutname, 'block_myoverview');
+        $layout->active = $this->view == $layoutname ? true : false;
+        $layout->arialabel = get_string('aria:' . $layoutname, 'block_myoverview');
+
+        return $layout;
+    }
+
+    /**
+     * Get the available layouts formatted for export.
+     *
+     * @return array an array of objects representing available layouts
+     */
+    public function get_formatted_available_layouts_for_export() {
+
+        return array_map(array($this, 'format_layout_for_export'), $this->layouts);
+
+    }
+
     /**
      * Export this data so it can be used as the context for a mustache template.
      *
@@ -118,16 +183,20 @@ public function export_for_template(renderer_base $output) {
 
         $nocoursesurl = $output->image_url('courses', 'block_myoverview')->out();
 
+        $preferences = $this->get_preferences_as_booleans();
+        $availablelayouts = $this->get_formatted_available_layouts_for_export();
+
         $defaultvariables = [
             'nocoursesimg' => $nocoursesurl,
             'grouping' => $this->grouping,
             'sort' => $this->sort == BLOCK_MYOVERVIEW_SORTING_TITLE ? 'fullname' : 'ul.timeaccess desc',
-            'view' => $this->view,
+            // If the user preference display option is not available, default to first available layout.
+            'view' => in_array($this->view, $this->layouts) ? $this->view : reset($this->layouts),
             'paging' => $this->paging,
+            'layouts' => $availablelayouts,
             'displaycategories' => $this->displaycategories,
+            'displaydropdown' => (count($availablelayouts) > 1) ? true : false,
         ];
-
-        $preferences = $this->get_preferences_as_booleans();
         return array_merge($defaultvariables, $preferences);
 
     }

blocks/myoverview/classes/output/main.php

@@ -55,6 +55,8 @@
 $string['future'] = 'Future';
 $string['inprogress'] = 'In progress';
 $string['lastaccessed'] = 'Last accessed';
+$string['layouts'] = 'Available Layouts';
+$string['layouts_help'] = 'The layouts which are available for selection by users';
 $string['list'] = 'List';
 $string['myoverview:myaddinstance'] = 'Add a new course overview block to Dashboard';
 $string['past'] = 'Past';

blocks/myoverview/lang/en/block_myoverview.php

@@ -44,7 +44,7 @@
 /**
  * Constants for the user preferences view options
  */
-define('BLOCK_MYOVERVIEW_VIEW_CARD', 'cards');
+define('BLOCK_MYOVERVIEW_VIEW_CARD', 'card');
 define('BLOCK_MYOVERVIEW_VIEW_LIST', 'list');
 define('BLOCK_MYOVERVIEW_VIEW_SUMMARY', 'summary');