MDL-52378 Singleview: Exclude Grade Attribute Permissions

Singleview users must have Manage Grade permission to modify the
Exclude grade attribute.

grade/report/singleview/classes/local/screen/screen.php

@@ -329,6 +329,13 @@ abstract class screen {
                 continue;
             }
 
+            // If the user submits Exclude grade elements without the proper 
+            // permissions then we should refuse to update.
+            if ($matches[1] === 'exclude' && !has_capability('moodle/grade:manage', $this->context)){
+                $warnings[] = get_string('nopermissions', 'error', get_string('grade:manage', 'role'));
+                continue;
+            }
+
             $msg = $element->set($posted);
 
             // Optional type.

grade/report/singleview/classes/local/screen/tablelike.php

@@ -141,6 +141,12 @@ abstract class tablelike extends screen {
                 $html .= $this->structure->get_grade_analysis_icon($grade);
             }
 
+            // Singleview users without proper permissions should be presented
+            // disabled checkboxes for the Exclude grade attribute.
+            if ($field == 'exclude' && !has_capability('moodle/grade:manage', $this->context)){
+                $html->locked=TRUE;
+            }
+
             $line[] = $html;
         }
         return $line;

grade/report/singleview/classes/local/ui/exclude.php

@@ -40,6 +40,9 @@ class exclude extends grade_attribute_format implements be_checked {
     /** @var string $name The name of the input */
     public $name = 'exclude';
 
+    /** @var bool $locked Is the input locked? */
+    public $locked = FALSE;
+
     /**
      * Is it checked?
      *
@@ -49,6 +52,15 @@ class exclude extends grade_attribute_format implements be_checked {
         return $this->grade->is_excluded();
     }
 
+    /**
+     * Is it locked?
+     *
+     * @return bool
+     */
+    public function is_locked() {
+        return $this->locked;
+    }
+
     /**
      * Generate the element used to render the UI
      *
@@ -58,7 +70,9 @@ class exclude extends grade_attribute_format implements be_checked {
         return new checkbox_attribute(
             $this->get_name(),
             $this->get_label(),
-            $this->is_checked()
+            $this->is_checked(),
+            // Call checkbox constructor with locked attribute, expects integer.
+            $this->is_locked() ? 1 : 0  
         );
     }