MDL-38196 Backup/restore: Display log if non-empty

When doing a backup or restore operation with the normal user interface,
if there is anything in the backup/restore log, it will now be displayed
at the end of the process below the Continue button.

If you have developer debugging enabled, it sets the display level to
LOG_DEBUG and there will always be content in the log. Otherwise, it
uses LOG_INFO which generally means the log is empty, and nothing
displays (no visible change for users).

backup/controller/backup_controller.class.php

@@ -40,7 +40,7 @@
  *
  * TODO: Finish phpdocs
  */
-class backup_controller extends backup implements loggable {
+class backup_controller extends base_controller {
 
     protected $backupid; // Unique identificator for this backup
 
@@ -62,12 +62,6 @@ class backup_controller extends backup implements loggable {
     protected $executiontime; // epoch time when we want the backup to be executed (requires cron to run)
 
     protected $destination; // Destination chain object (fs_moodle, fs_os, db, email...)
-    protected $logger;      // Logging chain object (moodle, inline, fs, db, syslog)
-
-    /**
-     * @var core_backup_progress Progress reporting object.
-     */
-    protected $progress;
 
     protected $checksum; // Cache @checksumable results for lighter @is_checksum_correct() uses
 
@@ -307,29 +301,6 @@ class backup_controller extends backup implements loggable {
         return $this->plan;
     }
 
-    public function get_logger() {
-        return $this->logger;
-    }
-
-    /**
-     * Gets the progress reporter, which can be used to report progress within
-     * the backup or restore process.
-     *
-     * @return core_backup_progress Progress reporting object
-     */
-    public function get_progress() {
-        return $this->progress;
-    }
-
-    /**
-     * Sets the progress reporter.
-     *
-     * @param core_backup_progress $progress Progress reporting object
-     */
-    public function set_progress(core_backup_progress $progress) {
-        $this->progress = $progress;
-    }
-
     /**
      * Executes the backup
      * @return void Throws and exception of completes
@@ -353,10 +324,6 @@ class backup_controller extends backup implements loggable {
         return $this->plan->get_results();
     }
 
-    public function log($message, $level, $a = null, $depth = null, $display = false) {
-        backup_helper::log($message, $level, $a, $depth, $display, $this->logger);
-    }
-
     /**
      * Save controller information
      *

backup/controller/base_controller.class.php

@@ -0,0 +1,85 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Base class with shared stuff between backup controller and restore
+ * controller.
+ *
+ * @package core_backup
+ * @copyright 2013 The Open University
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+abstract class base_controller extends backup implements loggable {
+    /**
+     * @var core_backup_progress Progress reporting object.
+     */
+    protected $progress;
+
+    /**
+     * @var base_logger Logging chain object (moodle, inline, fs, db, syslog)
+     */
+    protected $logger;
+
+    /**
+     * Gets the progress reporter, which can be used to report progress within
+     * the backup or restore process.
+     *
+     * @return core_backup_progress Progress reporting object
+     */
+    public function get_progress() {
+        return $this->progress;
+    }
+
+    /**
+     * Sets the progress reporter.
+     *
+     * @param core_backup_progress $progress Progress reporting object
+     */
+    public function set_progress(core_backup_progress $progress) {
+        $this->progress = $progress;
+    }
+
+    /**
+     * Gets first logger in logging chain.
+     *
+     * @return base_logger Logger
+     */
+    public function get_logger() {
+        return $this->logger;
+    }
+
+    /**
+     * Inserts a new logger at end of logging chain.
+     *
+     * @param base_logger $logger New logger to add
+     */
+    public function add_logger(base_logger $logger) {
+        $existing = $this->logger;
+        while ($existing->get_next()) {
+            $existing = $existing->get_next();
+        }
+        $existing->set_next($logger);
+    }
+
+    /**
+     * Logs data to the logger chain.
+     *
+     * @see loggable::log()
+     */
+    public function log($message, $level, $a = null, $depth = null, $display = false) {
+        backup_helper::log($message, $level, $a, $depth, $display, $this->logger);
+    }
+}

backup/controller/restore_controller.class.php

@@ -30,7 +30,7 @@
  *
  * TODO: Finish phpdocs
  */
-class restore_controller extends backup implements loggable {
+class restore_controller extends base_controller {
 
     protected $tempdir;   // Directory under tempdir/backup awaiting restore
     protected $restoreid; // Unique identificator for this restore
@@ -55,13 +55,6 @@ class restore_controller extends backup implements loggable {
     protected $execution;     // inmediate/delayed
     protected $executiontime; // epoch time when we want the restore to be executed (requires cron to run)
 
-    protected $logger;      // Logging chain object (moodle, inline, fs, db, syslog)
-
-    /**
-     * @var core_backup_progress Progress reporting object.
-     */
-    protected $progress;
-
     protected $checksum; // Cache @checksumable results for lighter @is_checksum_correct() uses
 
     /**
@@ -305,29 +298,6 @@ class restore_controller extends backup implements loggable {
         return $this->info;
     }
 
-    public function get_logger() {
-        return $this->logger;
-    }
-
-    /**
-     * Gets the progress reporter, which can be used to report progress within
-     * the backup or restore process.
-     *
-     * @return core_backup_progress Progress reporting object
-     */
-    public function get_progress() {
-        return $this->progress;
-    }
-
-    /**
-     * Sets the progress reporter.
-     *
-     * @param core_backup_progress $progress Progress reporting object
-     */
-    public function set_progress(core_backup_progress $progress) {
-        $this->progress = $progress;
-    }
-
     public function execute_plan() {
         // Basic/initial prevention against time/memory limits
         set_time_limit(1 * 60 * 60); // 1 hour for 1 course initially granted
@@ -395,10 +365,6 @@ class restore_controller extends backup implements loggable {
         return $this->precheck;
     }
 
-    public function log($message, $level, $a = null, $depth = null, $display = false) {
-        backup_helper::log($message, $level, $a, $depth, $display, $this->logger);
-    }
-
     /**
      * Save controller information
      *