Enable plugins to be "initialized" to, for example, register event li…

…steners

README.md

@@ -65,8 +65,30 @@ storage:
 reporting:
     my_own_html_reporting: ~
 ```
+
 </details>
 
+## Plugins
+
+As Panaly is building on a wide plugin system and is not delivering metric collecting, storaging and reporting features
+by itself everything needs to be done by a plugin. Each plugin can be specialized to a single task or deliver a full
+feature set from the metric collection over storage handling to reporting generation.
+
+In a result the plugins are the most basic thing to configure for a Panaly run. Every plugin has a base class that is
+configuring how the plugin want to be utilized by Panaly and which features it delivers.
+
+A Plugin can extend the class `Panaly\Plugin\BasePlugin` to not have to implement all methods for itself as the methods
+are independently called from each other and nothing will happen when they are empty.
+
+The following methods are available.
+
+| Method                  | Description                                                                                                                                                                                   |
+|-------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `initialize`            | Mainly usage idea currently is to register event listeners to the events that are triggered during the runtime of a Panaly run.                                                               |
+| `getAvailableMetrics`   | Return a list of `Panaly\Plugin\Plugin\Metric` implementing classes to be used as metric collectors.                                                                                          |
+| `getAvailableStorages`  | Return a list of `Panaly\Plugin\Plugin\Storage` implementing classes that will take the metric collection result and handle storage tasks.                                                    |
+| `getAvailableReporting` | Return a list of `Panaly\Plugin\Plugin\Reporting` implementing classes that will take the metric collection result and generate some kind of reporting that can then be utilized by the user. |
+
 ## Events
 
 The event section is work in progress as there is currently no real way to register an event listener but that will

bin/panaly

@@ -39,7 +39,7 @@ require __DIR__ . '/../vendor/autoload.php';
         // The configuration file is parsed, so allow to change the configuration when there is any need for it, before the plugins are loaded
         $runtimeConfiguration->getEventDispatcher()->dispatch($event = new ConfigurationLoaded($configurationFile));
 
-        // Load the plugins to get knowledge about all registered components for the runtime cofiguratioon
+        // Load the plugins to get knowledge about all registered components for the runtime configuration
         (new Configuration\PluginLoader())->load($event->getConfigurationFile(), $runtimeConfiguration);
 
         // Give the possibility to change the runtime configuration before the metric collection starts

src/Configuration/PluginLoader.php

@@ -23,6 +23,8 @@ public function load(ConfigurationFile $configurationFile, RuntimeConfiguration
                 throw PluginLoadingFailed::instantiationFailed($plugin->class, $e);
             }
 
+            $loadedPlugin->initialize($configurationFile, $runtimeConfiguration);
+
             $loadedPluginMetrics = $loadedPlugin->getAvailableMetrics();
             array_walk(
                 $loadedPluginMetrics,

src/Plugin/BasePlugin.php

@@ -4,12 +4,20 @@
 
 namespace Panaly\Plugin;
 
+use Panaly\Configuration\ConfigurationFile;
+use Panaly\Configuration\RuntimeConfiguration;
 use Panaly\Plugin\Plugin\Metric;
 use Panaly\Plugin\Plugin\Reporting;
 use Panaly\Plugin\Plugin\Storage;
 
 abstract class BasePlugin implements Plugin
 {
+    public function initialize(ConfigurationFile $configurationFile, RuntimeConfiguration $runtimeConfiguration): void
+    {
+        // Do nothing by design ... it just has to be overwritten when there is something to do
+        // Idea: Maybe allow also a plugin configuration that could be given here in the future?
+    }
+
     /** @return list<Metric> */
     public function getAvailableMetrics(): array
     {

src/Plugin/Plugin.php

@@ -4,12 +4,21 @@
 
 namespace Panaly\Plugin;
 
+use Panaly\Configuration\ConfigurationFile;
+use Panaly\Configuration\RuntimeConfiguration;
 use Panaly\Plugin\Plugin\Metric;
 use Panaly\Plugin\Plugin\Reporting;
 use Panaly\Plugin\Plugin\Storage;
 
 interface Plugin
 {
+    /**
+     * The method is called to give a plugin the possibility to do something with the configuration file and runtime
+     * configuration on loading. Enables, for example, access to the event dispatcher which is given in the runtime
+     * configuration and so allows to register listeners or subscriber to it.
+     */
+    public function initialize(ConfigurationFile $configurationFile, RuntimeConfiguration $runtimeConfiguration): void;
+
     /** @return list<Metric> */
     public function getAvailableMetrics(): array;
 

tests/Fixtures/Plugin/TestPlugin.php

@@ -5,7 +5,7 @@
 namespace Panaly\Test\Fixtures\Plugin;
 
 use InvalidArgumentException;
-use Panaly\Plugin\Plugin;
+use Panaly\Plugin\BasePlugin;
 use Panaly\Plugin\Plugin\Metric;
 use Panaly\Plugin\Plugin\Reporting;
 use Panaly\Plugin\Plugin\Storage;
@@ -20,7 +20,7 @@
 use const JSON_PRETTY_PRINT;
 use const JSON_THROW_ON_ERROR;
 
-class TestPlugin implements Plugin
+class TestPlugin extends BasePlugin
 {
     /** @return list<Metric> */
     public function getAvailableMetrics(): array