Extend Observer declaration in events.xml by new attribute ifconfig

lib/internal/Magento/Framework/Event/Config/Converter.php

@@ -1,7 +1,7 @@
 <?php
 /**
- * Copyright © Magento, Inc. All rights reserved.
- * See COPYING.txt for license details.
+ * Copyright 2013 Adobe
+ * All Rights Reserved.
  */
 namespace Magento\Framework\Event\Config;
 
@@ -77,6 +77,12 @@ public function _convertObserverConfig($observerConfig)
             $output['shared'] = false;
         }
 
+        /** Parse condition configuration */
+        $ifconfigAttribute = $observerConfig->attributes->getNamedItem('ifconfig');
+        if ($ifconfigAttribute && !empty($ifconfigAttribute->nodeValue)) {
+            $output['ifconfig'] = $ifconfigAttribute->nodeValue;
+        }
+
         return $output;
     }
 }

lib/internal/Magento/Framework/Event/Invoker/InvokerDefault.php

@@ -1,13 +1,12 @@
 <?php
 /**
- * Default event invoker
- *
- * Copyright © Magento, Inc. All rights reserved.
- * See COPYING.txt for license details.
+ * Copyright 2013 Adobe
+ * All Rights Reserved.
  */
 
 namespace Magento\Framework\Event\Invoker;
 
+use Magento\Framework\App\Config\ScopeConfigInterface;
 use Magento\Framework\Event\Observer;
 use Psr\Log\LoggerInterface;
 use Magento\Framework\App\State;
@@ -31,6 +30,11 @@ class InvokerDefault implements \Magento\Framework\Event\InvokerInterface
      */
     protected $_appState;
 
+    /**
+     * @var \Magento\Framework\App\Config\ScopeConfigInterface
+     */
+    protected $scopeConfig;
+
     /**
      * @var LoggerInterface
      */
@@ -39,15 +43,19 @@ class InvokerDefault implements \Magento\Framework\Event\InvokerInterface
     /**
      * @param \Magento\Framework\Event\ObserverFactory $observerFactory
      * @param State $appState
+     * @param \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig
      * @param LoggerInterface $logger
      */
     public function __construct(
         \Magento\Framework\Event\ObserverFactory $observerFactory,
         State $appState,
+        \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig = null,
         LoggerInterface $logger = null
     ) {
         $this->_observerFactory = $observerFactory;
         $this->_appState = $appState;
+        $this->scopeConfig = $scopeConfig ?: \Magento\Framework\App\ObjectManager::getInstance()
+            ->get(ScopeConfigInterface::class);
         $this->logger = $logger ?: \Magento\Framework\App\ObjectManager::getInstance()
             ->get(LoggerInterface::class);
     }
@@ -66,6 +74,10 @@ public function dispatch(array $configuration, Observer $observer)
             return;
         }
 
+        if (isset($configuration['ifconfig']) && $this->scopeConfig->isSetFlag($configuration['ifconfig']) === false) {
+            return;
+        }
+
         if (isset($configuration['shared']) && false === $configuration['shared']) {
             $object = $this->_observerFactory->create($configuration['instance']);
         } else {

lib/internal/Magento/Framework/Event/Test/Unit/CollectionTest.php

@@ -1,8 +1,7 @@
 <?php
 /**
- * @category   Magento
- * Copyright © Magento, Inc. All rights reserved.
- * See COPYING.txt for license details.
+ * Copyright 2014 Adobe
+ * All Rights Reserved.
  */
 declare(strict_types=1);
 
@@ -22,7 +21,7 @@ class CollectionTest extends TestCase
      */
     protected $collection;
 
-    /*
+    /**
      * Array of events in the collection
      *
      * @var array

lib/internal/Magento/Framework/Event/Test/Unit/Invoker/InvokerDefaultTest.php

@@ -1,7 +1,7 @@
 <?php
 /**
- * Copyright © Magento, Inc. All rights reserved.
- * See COPYING.txt for license details.
+ * Copyright 2013 Adobe
+ * All Rights Reserved.
  */
 declare(strict_types=1);
 
@@ -40,6 +40,11 @@ class InvokerDefaultTest extends TestCase
      */
     protected $_appStateMock;
 
+    /**
+     * @var MockObject
+     */
+    protected $_scopeConfigMock;
+
     /**
      * @var InvokerDefault
      */
@@ -59,11 +64,13 @@ protected function setUp(): void
             ['execute']
         );
         $this->_appStateMock = $this->createMock(State::class);
+        $this->_scopeConfigMock = $this->createMock(\Magento\Framework\App\Config::class);
         $this->loggerMock = $this->getMockForAbstractClass(LoggerInterface::class);
 
         $this->_invokerDefault = new InvokerDefault(
             $this->_observerFactoryMock,
             $this->_appStateMock,
+            $this->_scopeConfigMock,
             $this->loggerMock
         );
     }
@@ -215,4 +222,64 @@ public static function dataProviderForMethodIsNotDefined()
     {
         return ['shared' => [true], 'non shared' => [false]];
     }
+
+    public function testDispatchWithIfconfigFalse()
+    {
+        $this->_observerFactoryMock->expects($this->never())->method('get');
+        $this->_observerFactoryMock->expects($this->never())->method('create');
+
+        $this->_scopeConfigMock->expects(
+            $this->any()
+        )->method(
+            'isSetFlag'
+        )->with(
+            'test/path/value'
+        )->willReturn(
+            false
+        );
+
+        $this->_invokerDefault->dispatch(['ifconfig' => 'test/path/value'], $this->_observerMock);
+    }
+
+    public function testDispatchWithIfconfigTrue()
+    {
+        $this->_listenerMock->expects($this->once())->method('execute');
+        $this->_scopeConfigMock->expects(
+            $this->any()
+        )->method(
+            'isSetFlag'
+        )->with(
+            'test/path/value'
+        )->willReturn(
+            true
+        );
+        $this->_observerFactoryMock->expects(
+            $this->once()
+        )->method(
+            'get'
+        )->with(
+            'class_name'
+        )->willReturn(
+            $this->_listenerMock
+        );
+
+        $this->_invokerDefault->dispatch(['instance' => 'class_name',
+            'ifconfig' => 'test/path/value'], $this->_observerMock);
+    }
+
+    public function testDispatchWithIfconfigMissing()
+    {
+        $this->_listenerMock->expects($this->once())->method('execute');
+        $this->_observerFactoryMock->expects(
+            $this->once()
+        )->method(
+            'get'
+        )->with(
+            'class_name'
+        )->willReturn(
+            $this->_listenerMock
+        );
+
+        $this->_invokerDefault->dispatch(['instance' => 'class_name'], $this->_observerMock);
+    }
 }

lib/internal/Magento/Framework/Event/etc/events.xsd

@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
 /**
- * Copyright © Magento, Inc. All rights reserved.
- * See COPYING.txt for license details.
+ * Copyright 2013 Adobe
+ * All Rights Reserved.
  */
 -->
 <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
@@ -55,6 +55,7 @@
         <xs:attribute name="instance" type="xs:string" use="optional" />
         <xs:attribute name="disabled" type="xs:boolean" use="optional" />
         <xs:attribute name="shared" type="xs:boolean" use="optional" />
+        <xs:attribute name="ifconfig" type="xs:string" use="optional" />
     </xs:complexType>
 
     <xs:simpleType name="eventName">