Add EventDetailsExtensionHook and include it into EventController

modules/monitoring/application/controllers/EventController.php

@@ -5,6 +5,8 @@ namespace Icinga\Module\Monitoring\Controllers;
 
 use DateTime;
 use DateTimeZone;
+use Icinga\Module\Monitoring\Hook\EventDetailsExtensionHook;
+use Icinga\Application\Hook;
 use InvalidArgumentException;
 use Icinga\Data\Queryable;
 use Icinga\Date\DateFormatter;
@@ -70,6 +72,24 @@ class EventController extends Controller
             $this->getDetails($type, $event)
         );
 
+        $this->view->extensionsHtml = array();
+        /** @var EventDetailsExtensionHook $hook */
+        foreach (Hook::all('Monitoring\\EventDetailsExtension') as $hook) {
+            try {
+                $html = $hook->getHtmlForEvent($object);
+            } catch (\Exception $e) {
+                $html = $this->view->escape($e->getMessage());
+            }
+
+            if ($html) {
+                $module = $this->view->escape($hook->getModule()->getName());
+                $this->view->extensionsHtml[] =
+                    '<div class="icinga-module module-' . $module . '" data-icinga-module="' . $module . '">'
+                    . $html
+                    . '</div>';
+            }
+        }
+
         $this->view->title = $this->translate('Event Overview');
         $this->getTabs()
             ->add('event', array(

modules/monitoring/application/views/scripts/event/show.phtml

@@ -17,6 +17,12 @@ echo $object instanceof Service
 ?>
 </div>
 <div class="content">
+    <?php
+    foreach ($extensionsHtml as $extensionHtml) {
+        echo $extensionHtml;
+    }
+    ?>
+
     <h2><?= $this->escape($this->translate('Event Details')) ?></h2>
     <table class="event-details name-value-table" data-base-target="_next">
     <?php

modules/monitoring/library/Monitoring/Hook/EventDetailsExtensionHook.php

@@ -0,0 +1,79 @@
+<?php
+/* Icinga Web 2 | (c) 2017 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Module\Monitoring\Hook;
+
+use Icinga\Application\ClassLoader;
+use Icinga\Application\Icinga;
+use Icinga\Application\Modules\Module;
+
+/**
+ * Base class for hooks extending the event view of monitored objects
+ *
+ * Extend this class if you want to extend the event view of monitored objects with custom HTML.
+ */
+abstract class EventDetailsExtensionHook
+{
+    /**
+     * The module of the derived class
+     *
+     * @var Module
+     */
+    private $module;
+
+    /**
+     * Create a new hook
+     *
+     * @see init() For hook initialization.
+     */
+    final public function __construct()
+    {
+        $this->init();
+    }
+    /**
+     * Overwrite this function for hook initialization, e.g. loading the hook's config
+     */
+    protected function init()
+    {
+    }
+
+
+    /**
+     * Shall return valid HTML to include in the detail view
+     *
+     * @param   object $object     The object to generate HTML for
+     *
+     * @return  string
+     */
+    abstract public function getHtmlForEvent($event);
+
+    /**
+     * Get the module of the derived class
+     *
+     * @return Module
+     * @throws \Icinga\Exception\ProgrammingError
+     */
+    public function getModule()
+    {
+        if ($this->module === null) {
+            $class = get_class($this);
+            if (ClassLoader::classBelongsToModule($class)) {
+                $this->module = Icinga::app()->getModuleManager()->getModule(ClassLoader::extractModuleName($class));
+            }
+        }
+        return $this->module;
+    }
+
+    /**
+     * Set the module of the derived class
+     *
+     * @param Module $module
+     *
+     * @return $this
+     */
+    public function setModule(Module $module)
+    {
+        $this->module = $module;
+        return $this;
+    }
+}