From 1573636972d78c892646e6f9d70654be23716467 Mon Sep 17 00:00:00 2001
From: David Grudl <david@grudl.com>
Date: Wed, 17 Apr 2024 16:36:15 +0200
Subject: [PATCH] Presenter: added switch()

---
 src/Application/UI/Presenter.php              | 34 +++++++++++++++++--
 src/Application/exceptions.php                |  5 +++
 .../UI/LinkGenerator.parseDestination().phpt  |  2 +-
 tests/UI/Requires.forward.phpt                | 29 ++++++++++++++++
 4 files changed, 66 insertions(+), 4 deletions(-)

diff --git a/src/Application/UI/Presenter.php b/src/Application/UI/Presenter.php
index 68a78a748..635f88801 100644
--- a/src/Application/UI/Presenter.php
+++ b/src/Application/UI/Presenter.php
@@ -99,6 +99,7 @@ abstract class Presenter extends Control implements Application\IPresenter
 	private ?array $globalStateSinces;
 	private string $action = '';
 	private string $view = '';
+	private bool $forwarded = false;
 	private string|bool $layout = '';
 	private \stdClass $payload;
 	private string $signalReceiver;
@@ -188,7 +189,14 @@ public function run(Application\Request $request): Application\Response
 			}
 
 			// calls $this->action<Action>()
-			$this->tryCall(static::formatActionMethod($this->action), $this->params);
+			try {
+				actionMethod:
+				$this->tryCall(static::formatActionMethod($this->action), $this->params);
+			} catch (Application\SwitchException $e) {
+				$this->changeAction($e->getMessage());
+				$this->autoCanonicalize = false;
+				goto actionMethod;
+			}
 
 			// autoload components
 			foreach ($this->globalParams as $id => $foo) {
@@ -211,12 +219,20 @@ public function run(Application\Request $request): Application\Response
 			$this->beforeRender();
 			Arrays::invoke($this->onRender, $this);
 			// calls $this->render<View>()
-			$this->tryCall(static::formatRenderMethod($this->view), $this->params);
+			try {
+				renderMethod:
+				$this->tryCall(static::formatRenderMethod($this->view), $this->params);
+			} catch (Application\SwitchException $e) {
+				$this->setView($e->getMessage());
+				goto renderMethod;
+			}
 			$this->afterRender();
 
 			// finish template rendering
 			$this->sendTemplate();
 
+		} catch (Application\SwitchException $e) {
+			throw new Nette\InvalidStateException('Switch is only supported inside action*() or render*() method.', 0, $e);
 		} catch (Application\AbortException) {
 		}
 
@@ -327,7 +343,7 @@ public function checkRequirements(\ReflectionClass|\ReflectionMethod $element):
 			if (
 				$attribute->forward
 				&& !$this->request->isMethod($this->request::FORWARD)
-				&& $this->action === $this->view
+				&& !$this->forwarded
 			) {
 				$this->error('Forwarded request is required by ' . Reflection::toString($element));
 			}
@@ -451,10 +467,20 @@ final public function getAction(bool $fullyQualified = false): string
 	 */
 	public function changeAction(string $action): void
 	{
+		$this->forwarded = true;
 		$this->action = $this->view = $action;
 	}
 
 
+	/**
+	 * Switch from current action or render method to another.
+	 */
+	public function switch(string $action): never
+	{
+		throw new Application\SwitchException($action);
+	}
+
+
 	/**
 	 * Returns current view.
 	 */
@@ -469,6 +495,7 @@ final public function getView(): string
 	 */
 	public function setView(string $view): static
 	{
+		$this->forwarded = true;
 		$this->view = $view;
 		return $this;
 	}
@@ -1072,6 +1099,7 @@ private function initGlobalParameters(): void
 		}
 
 		$this->changeAction($action);
+		$this->forwarded = false;
 
 		// init $this->signalReceiver and key 'signal' in appropriate params array
 		$this->signalReceiver = $this->getUniqueId();
diff --git a/src/Application/exceptions.php b/src/Application/exceptions.php
index a23d83a10..11aea987d 100644
--- a/src/Application/exceptions.php
+++ b/src/Application/exceptions.php
@@ -20,6 +20,11 @@ class AbortException extends \LogicException
 {
 }
 
+/** @internal */
+final class SwitchException extends AbortException
+{
+}
+
 
 /**
  * Application fatal error.
diff --git a/tests/UI/LinkGenerator.parseDestination().phpt b/tests/UI/LinkGenerator.parseDestination().phpt
index d520bb51c..5132e99a4 100644
--- a/tests/UI/LinkGenerator.parseDestination().phpt
+++ b/tests/UI/LinkGenerator.parseDestination().phpt
@@ -2,8 +2,8 @@
 
 declare(strict_types=1);
 
-use Nette\Application\UI\InvalidLinkException;
 use Nette\Application\LinkGenerator;
+use Nette\Application\UI\InvalidLinkException;
 use Tester\Assert;
 
 
diff --git a/tests/UI/Requires.forward.phpt b/tests/UI/Requires.forward.phpt
index f54f030a3..63e1e289e 100644
--- a/tests/UI/Requires.forward.phpt
+++ b/tests/UI/Requires.forward.phpt
@@ -41,6 +41,22 @@ class TestForwardViewPresenter extends Nette\Application\UI\Presenter
 }
 
 
+class TestSwitchViewPresenter extends Nette\Application\UI\Presenter
+{
+	public function actionDefault(): void
+	{
+		$this->switch('forward');
+	}
+
+
+	#[Requires(forward: true)]
+	public function actionSwitch(): void
+	{
+		$this->terminate();
+	}
+}
+
+
 // forwarded request
 $presenter = createPresenter(TestForwardPresenter::class);
 Assert::noError(
@@ -65,3 +81,16 @@ Assert::exception(
 	Application\BadRequestException::class,
 	'Forwarded request is required by TestForwardViewPresenter::renderForward()',
 );
+
+
+// switched view
+$presenter = createPresenter(TestSwitchViewPresenter::class);
+Assert::noError(
+	fn() => $presenter->run(new Application\Request('', Http\Request::Get)),
+);
+
+Assert::exception(
+	fn() => $presenter->run(new Application\Request('', Http\Request::Get, ['action' => 'forward'])),
+	Application\BadRequestException::class,
+	'Forwarded request is required by TestSwitchViewPresenter::actionSwitch()',
+);