NEW: Event-driven snapshot actions

_config/config.yml

@@ -27,55 +27,66 @@ Name: snapshot-listeners
 ---
 SilverStripe\CMS\Controllers\CMSMain:
   extensions:
-    - SilverStripe\Snapshots\Listener\Page\CMSMainAction
+    - SilverStripe\Snapshots\Listener\CMSMain\Listener
 
 SilverStripe\Forms\GridField\GridField:
   extensions:
-    - SilverStripe\Snapshots\Listener\GridField\AlterAction
-    - SilverStripe\Snapshots\Listener\GridField\UrlHandlerAction
+    - SilverStripe\Snapshots\Listener\GridField\Alteration\Listener
+    - SilverStripe\Snapshots\Listener\GridField\Action\Listener
 
 SilverStripe\Forms\FormRequestHandler:
   extensions:
-    - SilverStripe\Snapshots\Listener\Form\Submission
+    - SilverStripe\Snapshots\Listener\Form\Listener
 
 SilverStripe\GraphQL\Scaffolding\Scaffolders\CRUD\Create:
   extensions:
-    - SilverStripe\Snapshots\Listener\GraphQL\GenericAction
+    - SilverStripe\Snapshots\Listener\GraphQL\Mutation\Listener
 
 SilverStripe\GraphQL\Scaffolding\Scaffolders\CRUD\Delete:
   extensions:
-    - SilverStripe\Snapshots\Listener\GraphQL\GenericAction
+    - SilverStripe\Snapshots\Listener\GraphQL\Mutation\Listener
 
 SilverStripe\GraphQL\Scaffolding\Scaffolders\CRUD\Update:
   extensions:
-    - SilverStripe\Snapshots\Listener\GraphQL\GenericAction
+    - SilverStripe\Snapshots\Listener\GraphQL\Mutation\Listener
 
 SilverStripe\GraphQL\Manager:
   extensions:
-    - SilverStripe\Snapshots\Listener\GraphQL\CustomAction
+    - SilverStripe\Snapshots\Listener\GraphQL\Middleware\Listener
 
 ---
-Name: snapshot-actions
+Name: snapshot-events
 ---
-SilverStripe\Snapshots\Snapshot:
-  actions:
-    # page edit form
-    'save': 'Save page'
-    'publish': 'Publish'
-    'unpublish': 'Unpublish'
-    # site tree
-    'savetreenode': 'Changed site tree position'
-    # grid field item edit form
-    'doSave': 'Save item'
-    'doDelete': 'Delete item'
-    # grid field actions (via standard action)
-    'deleterecord': 'Delete item'
-    # grid field actions (via form submission)
-    'handleReorder': 'Changed items order'
-    # linkable edit form
-    'doSaveLink': 'Link Edit'
-    'doRemoveLink': 'Link Delete'
-    # GraphQL CRUD
-    'graphql_crud_create': 'GraphQL create'
-    'graphql_crud_delete': 'GraphQL delete'
-    'graphql_crud_update': 'GraphQL update'
+SilverStripe\Core\Injector\Injector:
+  SilverStripe\Snapshots\Dispatch\Dispatcher:
+    properties:
+      handlers:
+        formGeneric:
+          on:
+            'formSubmitted.unpublish': true
+            'formSubmitted.doSave': true
+            'formSubmitted.doDelete': true
+          handler: %$SilverStripe\Snapshots\Handler\Form\Handler
+        save:
+          on:
+            'formSubmitted.save': true
+          handler: %$SilverStripe\Snapshots\Handler\Form\SaveHandler
+        publish:
+          on:
+            'formSubmitted.publish': true
+          handler: %$SilverStripe\Snapshots\Handler\Form\PublishHandler
+        cmsMain:
+          on:
+            'cmsAction.savetreenode': true
+          handler: %$SilverStripe\Snapshots\Handler\CMSMain\Handler
+        gridFieldAction:
+          on:
+            'gridFieldAlteration.deleterecord': true
+            'gridFieldAlteration.archiverecord': true
+          handler: %$SilverStripe\Snapshots\Handler\GridField\Action\Handler
+        graphqlMutation:
+          on:
+            'graphqlMutation.create': true
+            'graphqlMutation.update': true
+            'graphqlMutation.delete': true
+          handler: %$SilverStripe\Snapshots\Handler\GraphQL\Mutation\Handler

lang/en.yml

@@ -0,0 +1,18 @@
+en:
+  SilverStripe\Snapshots\Handler\Form\FormSubmissionHandler:
+    HANDLER_unpublish: 'Unpublish page'
+    HANDLER_doSave: 'Save item'
+    HANDLER_doDelete: 'Delete item'
+  SilverStripe\Snapshots\Handler\Form\SaveHandler:
+    HANDLER_save: 'Save page'
+  SilverStripe\Snapshots\Handler\Form\PublishHandler:
+    HANDLER_publish: 'Publish page'
+  SilverStripe\Snapshots\Handler\CMSMain\ActionHandler:
+    HANDLER_savetreenode: 'Reordered site tree'
+  SilverStripe\Snapshots\Handler\GraphQL\MutationHandler:
+    HANDLER_graphql_crud_create: 'GraphQL create'
+    HANDLER_graphql_crud_update: 'GraphQL update'
+    HANDLER_graphql_crud_delete: 'GraphQL delete'
+  SilverStripe\Snapshots\Handler\GridField\URLActionHandler:
+    HANDLER_deleterecord: 'Delete record'
+    HANDLER_archiverecord: 'Archive record'

src/ActivityEntry.php

@@ -4,6 +4,7 @@
 
 use SilverStripe\Versioned\Versioned;
 use SilverStripe\View\ArrayData;
+use Exception;
 
 class ActivityEntry extends ArrayData
 {
@@ -49,7 +50,7 @@ public static function createFromSnapshotItem(SnapshotItem $item)
             $previousVersion = Versioned::get_all_versions($item->ObjectClass, $item->ObjectID)
                 ->sort('Version', 'DESC')
                 ->first();
-            if ($previousVersion->exists()) {
+            if ($previousVersion && $previousVersion->exists()) {
                 $itemObj = $item->getItem($previousVersion->Version);
             // This is to deal with the case in which there is no previous version
             // it's better to give a faulty snapshot point than break the app
@@ -58,6 +59,14 @@ public static function createFromSnapshotItem(SnapshotItem $item)
             }
         }
 
+        if (!$itemObj) {
+            throw new Exception(sprintf(
+                'Could not resolve SnapshotItem %s to a previous %s version',
+                $item->ID,
+                $item->ObjectClass
+            ));
+        }
+
         return new static([
             'Subject' => $itemObj,
             'Action' => $flag,

src/Dispatch/Dispatcher.php

@@ -0,0 +1,171 @@
+<?php
+
+namespace SilverStripe\Snapshots\Dispatch;
+
+use SilverStripe\Core\Injector\Injectable;
+use SilverStripe\Snapshots\Handler\HandlerInterface;
+use InvalidArgumentException;
+use Exception;
+use SilverStripe\Snapshots\Listener\EventContext;
+
+class Dispatcher
+{
+    use Injectable;
+
+    /**
+     * @var EventHandlerLoader[]
+     */
+    private $loaders = [];
+
+    /**
+     * @var array HandlerInterface[]
+     */
+    private $handlers = [];
+
+    /**
+     * @var bool
+     */
+    private $initialised = false;
+
+    /**
+     * @param EventHandlerLoader[] $loaders
+     * @return $this
+     */
+    public function setLoaders($loaders = [])
+    {
+        foreach ($loaders as $loader) {
+            if (!$loader instanceof EventHandlerLoader) {
+                throw new InvalidArgumentException(sprintf(
+                    '%s not passed an instance of %s',
+                    __CLASS__,
+                    EventHandlerLoader::class
+                ));
+            }
+        }
+        $this->loaders = $loaders;
+
+        return $this;
+    }
+
+    /**
+     * @param array $handlers
+     * @throws Exception
+     */
+    public function setHandlers(array $handlers)
+    {
+        foreach ($handlers as $spec) {
+            if (!isset($spec['handler']) || !isset($spec['on'])) {
+                throw new InvalidArgumentException('Event handlers must have a "on" and "handler" nodes');
+            }
+            $on = is_array($spec['on']) ? $spec['on'] : [$spec['on']];
+            $handler = $spec['handler'];
+
+            if (!$handler instanceof HandlerInterface) {
+                throw new InvalidArgumentException(sprintf(
+                    'Handler for %s is not an instance of %s',
+                    implode(', ', $on),
+                    HandlerInterface::class
+                ));
+            }
+
+            foreach ($on as $eventName => $shouldInclude) {
+                if ($shouldInclude) {
+                    $this->addListener($eventName, $handler);
+                }
+            }
+        }
+    }
+
+    /**
+     * @param string $event
+     * @param HandlerInterface $handler
+     * @return $this
+     * @throws Exception
+     */
+    public function addListener(string $event, HandlerInterface $handler): self
+    {
+        if (!isset($this->handlers[$event])) {
+            $this->handlers[$event] = [];
+        }
+
+        foreach ($this->handlers[$event] as $existing) {
+            if ($existing === $handler) {
+                throw new Exception(sprintf(
+                    'Handler for %s has already been added',
+                    $event
+                ));
+            }
+        }
+        $this->handlers[$event][] = $handler;
+
+        return $this;
+    }
+
+    /**
+     * @param string $event
+     * @param HandlerInterface $handler
+     * @return $this
+     */
+    public function removeListener(string $event, HandlerInterface $handler): self
+    {
+        $handlers = $this->handlers[$event] ?? [];
+        $this->handlers = array_filter($handlers, function ($existing) use ($handler) {
+            return $existing !== $handler;
+        });
+
+        return $this;
+    }
+
+    /**
+     * @param string $event
+     * @param string $className
+     * @return $this
+     */
+    public function removeListenerByClassName(string $event, string $className): self
+    {
+        $handlers = $this->handlers[$event] ?? [];
+        $this->handlers = array_filter($handlers, function ($existing) use ($className) {
+            return get_class($existing) !== $className;
+        });
+
+        return $this;
+    }
+
+    /**
+     * @param string $event
+     * @param EventContext $context
+     */
+    public function trigger(string $event, EventContext $context): void
+    {
+        // TODO: This could be moved to procedural code in something like _config.php,
+        // or add a new class that bootstraps the dispatcher.
+        $this->initialise();
+
+        $action = $context->getAction();
+        if ($action === null) {
+            return;
+        }
+
+        // First fire listeners to <eventName.actionName>, then just fire generic <eventName> listeners
+        $eventsToFire = [ $event . '.' . $action, $event];
+        foreach ($eventsToFire as $event) {
+            $handlers = $this->handlers[$event] ?? [];
+            /* @var HandlerInterface $handler */
+            foreach ($handlers as $handler) {
+                $handler->fire($context);
+            }
+        }
+    }
+
+    private function initialise(): void
+    {
+        if ($this->initialised) {
+            return;
+        }
+
+        foreach ($this->loaders as $loader) {
+            $loader->addToDispatcher($this);
+        }
+        $this->initialised = true;
+    }
+}

src/Dispatch/EventHandlerLoader.php

@@ -0,0 +1,9 @@
+<?php
+
+
+namespace SilverStripe\Snapshots\Dispatch;
+
+interface EventHandlerLoader
+{
+    public function addToDispatcher(Dispatcher $dispatcher): void;
+}

src/Handler/CMSMain/Handler.php

@@ -0,0 +1,55 @@
+<?php
+
+
+namespace SilverStripe\Snapshots\Handler\CMSMain;
+
+use SilverStripe\CMS\Model\SiteTree;
+use SilverStripe\Control\HTTPResponse;
+use SilverStripe\ORM\DataObject;
+use SilverStripe\ORM\ValidationException;
+use SilverStripe\Snapshots\Handler\HandlerAbstract;
+use SilverStripe\Snapshots\Listener\EventContext;
+use SilverStripe\Snapshots\Snapshot;
+
+class Handler extends HandlerAbstract
+{
+    /**
+     * @param EventContext $context
+     * @return Snapshot|null
+     * @throws ValidationException
+     */
+    protected function createSnapshot(EventContext $context): ?Snapshot
+    {
+        $action = $context->getAction();
+        if ($action === null) {
+            return null;
+        }
+
+        /* @var HTTPResponse $result */
+        $result = $context->get('result');
+        if (!$result instanceof HTTPResponse) {
+            return null;
+        }
+        if ((int) $result->getStatusCode() !== 200) {
+            return null;
+        }
+
+        $className = $context->get('treeClass');
+        $id = (int) $context->get('id');
+
+        if (!$id) {
+            return null;
+        }
+
+        /** @var SiteTree $page */
+        $page = DataObject::get_by_id($className, $id);
+
+        if ($page === null) {
+            return null;
+        }
+
+        $message = $this->getMessage($action);
+
+        return Snapshot::singleton()->createSnapshotFromAction($page, null, $message);
+    }
+}