MDL-30669 - blocks: Added a warning when deleting blocks that have mu…

…ltiple displays set.

Also added a fix to the function course_page_type_list(). It was making a call to
get_context_info_array() which will generate an error if $currentcontext is not set.

course/lib.php

@@ -3684,16 +3684,18 @@ protected function notify($touser, $fromuser, $name='courserequested', $subject,
  * @param stdClass $currentcontext Current context of block
  */
 function course_page_type_list($pagetype, $parentcontext, $currentcontext) {
-    // if above course context ,display all course fomats
-    list($currentcontext, $course, $cm) = get_context_info_array($currentcontext->id);
-    if ($course->id == SITEID) {
-        return array('*'=>get_string('page-x', 'pagetype'));
-    } else {
-        return array('*'=>get_string('page-x', 'pagetype'),
-            'course-*'=>get_string('page-course-x', 'pagetype'),
-            'course-view-*'=>get_string('page-course-view-x', 'pagetype')
-        );
+    // $currentcontext could be null, get_context_info_array() will throw an error if this is the case.
+    if (isset($currentcontext)) {
+        // if above course context ,display all course fomats
+        list($currentcontext, $course, $cm) = get_context_info_array($currentcontext->id);
+        if ($course->id == SITEID) {
+            return array('*'=>get_string('page-x', 'pagetype'));
+        }
     }
+    return array('*'=>get_string('page-x', 'pagetype'),
+        'course-*'=>get_string('page-course-x', 'pagetype'),
+        'course-view-*'=>get_string('page-course-view-x', 'pagetype')
+    );
 }
 
 /**

lang/en/block.php

@@ -42,6 +42,7 @@
 $string['deletecheck'] = 'Delete {$a} block?';
 $string['deleteblock'] = 'Delete {$a} block';
 $string['deleteblockcheck'] = 'Are you sure that you want to delete this block titled {$a}?';
+$string['deleteblockwarning'] = '<p>You are about to delete a block that appears elsewhere.</p><p>Original block location: {$a->location}<br />Display on page types: {$a->pagetype}</p><p>Are you sure you want to continue?</p>';
 $string['hideblock'] = 'Hide {$a} block';
 $string['hidedockpanel'] = 'Hide the dock panel';
 $string['hidepanel'] = 'Hide panel';

lib/blocklib.php

@@ -1176,6 +1176,27 @@ public function process_url_delete() {
             $strdeletecheck = get_string('deletecheck', 'block', $blocktitle);
             $message = get_string('deleteblockcheck', 'block', $blocktitle);
 
+            // If the block is being shown in sub contexts display a warning.
+            if ($block->instance->showinsubcontexts == 1) {
+                $parentcontext = context::instance_by_id($block->instance->parentcontextid);
+                $systemcontext = context_system::instance();
+                $messagestring = new stdClass();
+                $messagestring->location = $parentcontext->get_context_name();
+
+                // Checking for blocks that may have visibility on the front page and pages added on that.
+                if ($parentcontext->id != $systemcontext->id && is_inside_frontpage($parentcontext)) {
+                    $messagestring->pagetype = get_string('showonfrontpageandsubs', 'block');
+                } else {
+                    $pagetypes = generate_page_type_patterns($this->page->pagetype, $parentcontext);
+                    $messagestring->pagetype = $block->instance->pagetypepattern;
+                    if (isset($pagetypes[$block->instance->pagetypepattern])) {
+                        $messagestring->pagetype = $pagetypes[$block->instance->pagetypepattern];
+                    }
+                }
+
+                $message = get_string('deleteblockwarning', 'block', $messagestring);
+            }
+
             $PAGE->navbar->add($strdeletecheck);
             $PAGE->set_title($blocktitle . ': ' . $strdeletecheck);
             $PAGE->set_heading($site->fullname);