L05DOCBST-38 add init method to LoggerTrait

src/library/LoggerTrait.php

@@ -26,6 +26,48 @@ trait LoggerTrait {
      */
     protected $ndc_context = [];
 
+
+    /**
+     * initialize logger
+     *
+     * @param array $settings with (optional) keys: name, path, level and format
+     * @param string $base_dir base direcory for relative paths
+     * @return $this
+     */
+    public function init_logger(array $settings, string $base_dir = ".") {
+
+        $name = isset($settings["name"]) ? $settings["name"] : "default";
+        $path =  isset($settings["path"]) ? $settings["path"] : "php://stderr";
+        // adjust log path if it is not a php i/o stream or absolute path
+        // so only adjust relative paths
+        if (strncmp($path, 'php:', 4) != 0 && strncmp($path, '/', 1)) {
+            $path = "$base_dir/$path";
+        }
+        $level = isset($settings["level"]) ? $settings["level"] : "info";
+        $format = isset($settings["format"]) ? $settings["format"] : "[%datetime%] %channel% %level_name% %extra% %context%: %message%";
+
+        // create the logger
+        $logger = new \Monolog\Logger($name);
+        // add stream handler
+        $stream = new \Monolog\Handler\StreamHandler($path, $level);
+        $formatter = new \Monolog\Formatter\LineFormatter("$format\n");
+        $stream->setFormatter($formatter);
+        $logger->pushHandler($stream);
+
+        return $this->set_logger($logger);
+    }
+
+
+    /**
+     * get logger instance
+     * @return \Psr\Log\LoggerInterface or null if not set
+     */
+    public function get_logger() {
+
+        return $this->logger;
+    }
+
+
     /**
      * set logger to send log messages to
      * @param \Psr\Log\LoggerInterface $logger