streamline database loading

This removes the init() method in the helper and handles all database
initialization in getDB(), lazyloading it only when accessed.

If an exception happens during the initialization it is logged before
signaling the no sqlite cause.

Author: splitbrain

helper/db.php

@@ -7,57 +7,36 @@
  * @author  Andreas Gohr, Michael Große <dokuwiki@cosmocode.de>
  */
 
-use dokuwiki\Extension\Event;
+use dokuwiki\ErrorHandler;
+use dokuwiki\plugin\sqlite\SQLiteDB;
 use dokuwiki\plugin\struct\meta\StructException;
 
 class helper_plugin_struct_db extends DokuWiki_Plugin
 {
-    /** @var \dokuwiki\plugin\sqlite\SQLiteDB */
+    /** @var SQLiteDB */
     protected $sqlite;
 
-    /**
-     * helper_plugin_struct_db constructor.
-     */
-    public function __construct()
-    {
-        $this->init();
-    }
-
-    /**
-     * Initialize the database
-     *
-     * @throws Exception
-     */
-    protected function init()
-    {
-        try {
-            /** @var \dokuwiki\plugin\sqlite\SQLiteDB $sqlite */
-            $this->sqlite = new \dokuwiki\plugin\sqlite\SQLiteDB('struct', DOKU_PLUGIN . 'struct/db/');
-        } catch (Exception $exception) {
-            if (defined('DOKU_UNITTEST')) throw new \Exception('Couldn\'t load sqlite.');
-            return;
-        }
-
-        // register our JSON function with variable parameters
-        $this->sqlite->getPdo()->sqliteCreateFunction('STRUCT_JSON', [$this, 'STRUCT_JSON'], -1);
-
-        // this function is meant to be overwritten by plugins
-        $this->sqlite->getPdo()->sqliteCreateFunction('IS_PUBLISHER', [$this, 'IS_PUBLISHER'], -1);
-    }
-
     /**
      * @param bool $throw throw an Exception when sqlite not available
-     * @return \dokuwiki\plugin\sqlite\SQLiteDB|null
+     * @return SQLiteDB|null
      */
     public function getDB($throw = true)
     {
-        global $conf;
-        $len = strlen($conf['metadir']);
-        if ($this->sqlite && $conf['metadir'] != substr($this->sqlite->getDbFile(), 0, $len)) {
-            $this->init();
-        }
-        if (!$this->sqlite && $throw) {
-            throw new StructException('no sqlite');
+        if ($this->sqlite === null) {
+            try {
+                $this->sqlite = new SQLiteDB('struct', DOKU_PLUGIN . 'struct/db/');
+            } catch (\Exception $exception) {
+                if (defined('DOKU_UNITTEST')) throw new \RuntimeException('Could not load SQLite', 0, $exception);
+                ErrorHandler::logException($exception);
+                if ($throw) throw new StructException('no sqlite');
+                return null;
+            }
+
+            // register our JSON function with variable parameters
+            $this->sqlite->getPdo()->sqliteCreateFunction('STRUCT_JSON', [$this, 'STRUCT_JSON'], -1);
+
+            // this function is meant to be overwritten by plugins
+            $this->sqlite->getPdo()->sqliteCreateFunction('IS_PUBLISHER', [$this, 'IS_PUBLISHER'], -1);
         }
         return $this->sqlite;
     }
@@ -74,7 +53,7 @@ public function resetDB()
         if (!$file) return;
         unlink($file);
         clearstatcache(true, $file);
-        $this->init();
+        $this->sqlite = null;
     }
 
     /**