Implement DetailviewExtensionHook

refs #2104

modules/monitoring/application/views/scripts/partials/object/detail-content.phtml

@@ -1,6 +1,7 @@
 <div class="content" data-base-target="_next">
     <?= $this->render('show/components/output.phtml') ?>
     <?= $this->render('show/components/grapher.phtml') ?>
+    <?= $this->render('show/components/extensions.phtml') ?>
 
     <h2><?= $this->translate('Problem handling') ?></h2>
     <table class="name-value-table">

modules/monitoring/application/views/scripts/show/components/extensions.phtml

@@ -0,0 +1,4 @@
+<?php
+foreach ($extensionsHtml as $extensionHtml) {
+    echo $extensionHtml;
+}

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

@@ -0,0 +1,40 @@
+<?php
+/* Icinga Web 2 | (c) 2017 Icinga Development Team | GPLv2+ */
+
+namespace Icinga\Module\Monitoring\Hook;
+
+use Icinga\Module\Monitoring\Object\MonitoredObject;
+
+/**
+ * Base class for hooks extending the detail view of monitored objects
+ *
+ * Extend this class if you want to extend the detail view of monitored objects with custom HTML.
+ */
+abstract class DetailviewExtensionHook
+{
+    /**
+     * 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   MonitoredObject $object     The object to generate HTML for
+     *
+     * @return  string
+     */
+    abstract public function getHtmlForObject(MonitoredObject $object);
+}

modules/monitoring/library/Monitoring/Web/Controller/MonitoredObjectController.php

@@ -10,6 +10,7 @@ use Icinga\Module\Monitoring\Forms\Command\Object\DeleteDowntimeCommandForm;
 use Icinga\Module\Monitoring\Forms\Command\Object\ObjectsCommandForm;
 use Icinga\Module\Monitoring\Forms\Command\Object\RemoveAcknowledgementCommandForm;
 use Icinga\Module\Monitoring\Forms\Command\Object\ToggleObjectFeaturesCommandForm;
+use Icinga\Module\Monitoring\Hook\DetailviewExtensionHook;
 use Icinga\Web\Hook;
 use Icinga\Web\Url;
 use Icinga\Web\Widget\Tabextension\DashboardAction;
@@ -96,6 +97,12 @@ abstract class MonitoredObjectController extends Controller
         }
         $this->view->showInstance = $this->backend->select()->from('instance')->count() > 1;
         $this->view->object = $this->object;
+
+        $this->view->extensionsHtml = array();
+        foreach (Hook::all('Monitoring\DetailviewExtension') as $hook) {
+            /** @var DetailviewExtensionHook $hook */
+            $this->view->extensionsHtml[] = $hook->getHtmlForObject($this->object);
+        }
     }
 
     /**