library/log4php/renderers/LoggerRendererMap.php
changeset 0 4869aea77e21
new file mode 100644
--- /dev/null
+++ b/library/log4php/renderers/LoggerRendererMap.php
@@ -0,0 +1,186 @@
+<?php
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * @package log4php
+ */
+
+/**
+ * Manages defined renderers and determines which renderer to use for a given
+ * input.
+ *
+ * @version $Revision: 1394956 $
+ * @package log4php
+ * @subpackage renderers
+ * @since 0.3
+ */
+class LoggerRendererMap {
+
+    /**
+     * Maps class names to appropriate renderers.
+     * @var array
+     */
+    private $map = array();
+
+    /**
+     * The default renderer to use if no specific renderer is found.
+     * @var LoggerRenderer
+     */
+    private $defaultRenderer;
+
+    public function __construct() {
+
+        // Set default config
+        $this->reset();
+    }
+
+    /**
+     * Adds a renderer to the map.
+     *
+     * If a renderer already exists for the given <var>$renderedClass</var> it
+     * will be overwritten without warning.
+     *
+     * @param string $renderedClass The name of the class which will be
+     *        rendered by the renderer.
+     * @param string $renderingClass The name of the class which will
+     *        perform the rendering.
+     */
+    public function addRenderer($renderedClass, $renderingClass) {
+        // Check the rendering class exists
+        if (!class_exists($renderingClass)) {
+            trigger_error("log4php: Failed adding renderer. Rendering class [$renderingClass] not found.");
+            return;
+        }
+
+        // Create the instance
+        $renderer = new $renderingClass();
+
+        // Check the class implements the right interface
+        if (!($renderer instanceof LoggerRenderer)) {
+            trigger_error("log4php: Failed adding renderer. Rendering class [$renderingClass] does not implement the LoggerRenderer interface.");
+            return;
+        }
+
+        // Convert to lowercase since class names in PHP are not case sensitive
+        $renderedClass = strtolower($renderedClass);
+
+        $this->map[$renderedClass] = $renderer;
+    }
+
+    /**
+     * Sets a custom default renderer class.
+     *
+     * TODO: there's code duplication here. This method is almost identical to
+     * addRenderer(). However, it has custom error messages so let it sit for
+     * now.
+     *
+     * @param string $renderingClass The name of the class which will
+     *        perform the rendering.
+     */
+    public function setDefaultRenderer($renderingClass) {
+        // Check the class exists
+        if (!class_exists($renderingClass)) {
+            trigger_error("log4php: Failed setting default renderer. Rendering class [$renderingClass] not found.");
+            return;
+        }
+
+        // Create the instance
+        $renderer = new $renderingClass();
+
+        // Check the class implements the right interface
+        if (!($renderer instanceof LoggerRenderer)) {
+            trigger_error("log4php: Failed setting default renderer. Rendering class [$renderingClass] does not implement the LoggerRenderer interface.");
+            return;
+        }
+
+        $this->defaultRenderer = $renderer;
+    }
+
+    /**
+     * Returns the default renderer.
+     * @var LoggerRenderer
+     */
+    public function getDefaultRenderer() {
+        return $this->defaultRenderer;
+    }
+
+    /**
+     * Finds the appropriate renderer for the given <var>input</var>, and
+     * renders it (i.e. converts it to a string).
+     *
+     * @param mixed $input Input to render.
+     * @return string The rendered contents.
+     */
+    public function findAndRender($input) {
+        if ($input === null) {
+            return null;
+        }
+
+        // For objects, try to find a renderer in the map
+        if (is_object($input)) {
+            $renderer = $this->getByClassName(get_class($input));
+            if (isset($renderer)) {
+                return $renderer->render($input);
+            }
+        }
+
+        // Fall back to the default renderer
+        return $this->defaultRenderer->render($input);
+    }
+
+    /**
+     * Returns the appropriate renderer for a given object.
+     *
+     * @param mixed $object
+     * @return LoggerRenderer Or null if none found.
+     */
+    public function getByObject($object) {
+        if (!is_object($object)) {
+            return null;
+        }
+        return $this->getByClassName(get_class($object));
+    }
+
+    /**
+     * Returns the appropriate renderer for a given class name.
+     *
+     * If no renderer could be found, returns NULL.
+     *
+     * @param string $class
+     * @return LoggerRendererObject Or null if not found.
+     */
+    public function getByClassName($class) {
+        for (; !empty($class); $class = get_parent_class($class)) {
+            $class = strtolower($class);
+            if (isset($this->map[$class])) {
+                return $this->map[$class];
+            }
+        }
+        return null;
+    }
+
+    /** Empties the renderer map. */
+    public function clear() {
+        $this->map = array();
+    }
+
+    /** Resets the renderer map to it's default configuration. */
+    public function reset() {
+        $this->defaultRenderer = new LoggerRendererDefault();
+        $this->clear();
+        $this->addRenderer('Exception', 'LoggerRendererException');
+    }
+}