MDL-35429 backup: Only show relevant actions for automated backups

- Users without permission to download or restore won't see the
respective links.
- The 'Manage backup files' button for the 'automated' backup filearea
now requires the same permissions as downloading does for this filearea,
those being 'restore:userinfo' and 'backup:downloadfile'.

diff --git a/backup/backupfilesedit.php b/backup/backupfilesedit.php
index 86ce136..9c171ae 100644 (file)
--- a/backup/backupfilesedit.php
+++ b/backup/backupfilesedit.php
@@ -42,6 +42,9 @@ $url = new moodle_url('/backup/backupfilesedit.php', array('currentcontext'=>$cu
 
 require_login($course, false, $cm);
 require_capability('moodle/restore:uploadfile', $context);
+if ($filearea == 'automated' && !can_download_from_backup_filearea($filearea, $context)) {
+    throw new required_capability_exception($context, 'moodle/backup:downloadfile', 'nopermissions', '');
+}
 
 $PAGE->set_url($url);
 $PAGE->set_context($context);

diff --git a/backup/util/ui/renderer.php b/backup/util/ui/renderer.php
index b4855bb..7499d6f 100644 (file)
--- a/backup/util/ui/renderer.php
+++ b/backup/util/ui/renderer.php
@@ -573,27 +573,51 @@ class core_backup_renderer extends plugin_renderer_base {
             $params['contextid'] = $viewer->currentcontext->id;
             $params['itemid'] = $file->get_itemid();
             $restoreurl = new moodle_url('/backup/restorefile.php', $params);
+            $restorelink = html_writer::link($restoreurl, get_string('restore'));
+            $downloadlink = html_writer::link($fileurl, get_string('download'));
+
+            // Conditional display of the restore and download links, initially only for the 'automated' filearea.
+            if ($params['filearea'] == 'automated') {
+                if (!has_capability('moodle/restore:viewautomatedfilearea', $viewer->currentcontext)) {
+                    $restorelink = '';
+                }
+                if (!can_download_from_backup_filearea($params['filearea'], $viewer->currentcontext)) {
+                    $downloadlink = '';
+                }
+            }
             $table->data[] = array(
                 $file->get_filename(),
                 userdate($file->get_timemodified()),
                 display_size($file->get_filesize()),
-                html_writer::link($fileurl, get_string('download')),
-                html_writer::link($restoreurl, get_string('restore')),
+                $downloadlink,
+                $restorelink,
                 );
         }
 
         $html = html_writer::table($table);
-        $html .= $this->output->single_button(
-            new moodle_url('/backup/backupfilesedit.php', array(
-                'currentcontext' => $viewer->currentcontext->id,
-                'contextid' => $viewer->filecontext->id,
-                'filearea' => $viewer->filearea,
-                'component' => $viewer->component,
-                'returnurl' => $this->page->url->out())
-            ),
-            get_string('managefiles', 'backup'),
-            'post'
-        );
+
+        // For automated backups, the ability to manage backup files is controlled by the ability to download them.
+        // All files must be from the same file area in a backup_files_viewer.
+        $canmanagebackups = true;
+        if ($viewer->filearea == 'automated') {
+            if (!can_download_from_backup_filearea($viewer->filearea, $viewer->currentcontext)) {
+                $canmanagebackups = false;
+            }
+        }
+
+        if ($canmanagebackups) {
+            $html .= $this->output->single_button(
+                new moodle_url('/backup/backupfilesedit.php', array(
+                        'currentcontext' => $viewer->currentcontext->id,
+                        'contextid' => $viewer->filecontext->id,
+                        'filearea' => $viewer->filearea,
+                        'component' => $viewer->component,
+                        'returnurl' => $this->page->url->out())
+                ),
+                get_string('managefiles', 'backup'),
+                'post'
+            );
+        }
 
         return $html;
     }

diff --git a/course/lib.php b/course/lib.php
index b38c641..c688791 100644 (file)
--- a/course/lib.php
+++ b/course/lib.php
@@ -4266,3 +4266,32 @@ function course_require_view_participants($context) {
         throw new required_capability_exception($context, $viewparticipantscap, 'nopermissions', '');
     }
 }
+
+/**
+ * Return whether the user can download from the specified backup file area in the given context.
+ *
+ * @param string $filearea the backup file area. E.g. 'course', 'backup' or 'automated'.
+ * @param \context $context
+ * @param stdClass $user the user object. If not provided, the current user will be checked.
+ * @return bool true if the user is allowed to download in the context, false otherwise.
+ */
+function can_download_from_backup_filearea($filearea, \context $context, stdClass $user = null) {
+    $candownload = false;
+    switch ($filearea) {
+        case 'course':
+        case 'backup':
+            $candownload = has_capability('moodle/backup:downloadfile', $context, $user);
+            break;
+        case 'automated':
+            // Given the automated backups may contain userinfo, we restrict access such that only users who are able to
+            // restore with userinfo are able to download the file. Users can't create these backups, so checking 'backup:userinfo'
+            // doesn't make sense here.
+            $candownload = has_capability('moodle/backup:downloadfile', $context, $user) &&
+                           has_capability('moodle/restore:userinfo', $context, $user);
+            break;
+        default:
+            break;
+
+    }
+    return $candownload;
+}

diff --git a/course/tests/courselib_test.php b/course/tests/courselib_test.php
index 6d53ba5..78f1934 100644 (file)
--- a/course/tests/courselib_test.php
+++ b/course/tests/courselib_test.php
@@ -4074,4 +4074,54 @@ class core_course_courselib_testcase extends advanced_testcase {
         $this->expectException('required_capability_exception');
         course_require_view_participants(context_system::instance());
     }
+
+    /**
+     *  Testing the can_download_from_backup_filearea fn.
+     */
+    public function test_can_download_from_backup_filearea() {
+        global $DB;
+        $this->resetAfterTest();
+        $course = $this->getDataGenerator()->create_course();
+        $context = context_course::instance($course->id);
+        $user = $this->getDataGenerator()->create_user();
+        $teacherrole = $DB->get_record('role', array('shortname' => 'teacher'));
+        $this->getDataGenerator()->enrol_user($user->id, $course->id, $teacherrole->id);
+
+        // The 'automated' backup area. Downloading from this area requires two capabilities.
+        // If the user has only the 'backup:downloadfile' capability.
+        unassign_capability('moodle/restore:userinfo', $teacherrole->id, $context);
+        assign_capability('moodle/backup:downloadfile', CAP_ALLOW, $teacherrole->id, $context);
+        $this->assertFalse(can_download_from_backup_filearea('automated', $context, $user));
+
+        // If the user has only the 'restore:userinfo' capability.
+        unassign_capability('moodle/backup:downloadfile', $teacherrole->id, $context);
+        assign_capability('moodle/restore:userinfo', CAP_ALLOW, $teacherrole->id, $context);
+        $this->assertFalse(can_download_from_backup_filearea('automated', $context, $user));
+
+        // If the user has both capabilities.
+        assign_capability('moodle/backup:downloadfile', CAP_ALLOW, $teacherrole->id, $context);
+        assign_capability('moodle/restore:userinfo', CAP_ALLOW, $teacherrole->id, $context);
+        $this->assertTrue(can_download_from_backup_filearea('automated', $context, $user));
+
+        // Is the user has neither of the capabilities.
+        unassign_capability('moodle/backup:downloadfile', $teacherrole->id, $context);
+        unassign_capability('moodle/restore:userinfo', $teacherrole->id, $context);
+        $this->assertFalse(can_download_from_backup_filearea('automated', $context, $user));
+
+        // The 'course ' and 'backup' backup file areas. These are governed by the same download capability.
+        // User has the capability.
+        unassign_capability('moodle/restore:userinfo', $teacherrole->id, $context);
+        assign_capability('moodle/backup:downloadfile', CAP_ALLOW, $teacherrole->id, $context);
+        $this->assertTrue(can_download_from_backup_filearea('course', $context, $user));
+        $this->assertTrue(can_download_from_backup_filearea('backup', $context, $user));
+
+        // User doesn't have the capability.
+        unassign_capability('moodle/backup:downloadfile', $teacherrole->id, $context);
+        $this->assertFalse(can_download_from_backup_filearea('course', $context, $user));
+        $this->assertFalse(can_download_from_backup_filearea('backup', $context, $user));
+
+        // A file area that doesn't exist. No permissions, regardless of capabilities.
+        assign_capability('moodle/backup:downloadfile', CAP_ALLOW, $teacherrole->id, $context);
+        $this->assertFalse(can_download_from_backup_filearea('testing', $context, $user));
+    }
 }