Add "Set Title" action.

New action added.

This looks like a great improvement, thanks @VladimirAus for the contribution. The tests are reporting 3 issues, 2 of which a caused by the merge request. The third one is from a different code fraction and should be gone after you've rebased the fork.

@VladimirAus:
Weird local vs prod environment issue:
Local works, production throws warnings/errors and crashes out:

Error: Call to a member function replaceClear() on null in Drupal\eca_base\Plugin\Action\Title->execute() (line 44 of /app/web/modules/contrib/eca/modules/base/src/Plugin/Action/Title.php).

Warning: Undefined property: Drupal\eca_base\Plugin\Action\Title::$tokenService in Drupal\eca_base\Plugin\Action\Title->execute() (line 44 of /app/web/modules/contrib/eca/modules/base/src/Plugin/Action/Title.php)
#0 /app/web/core/includes/bootstrap.inc(164): _drupal_error_handler_real(2, 'Undefined prope...', '/app/web/module...', 44)
#1 /app/web/modules/contrib/eca/modules/base/src/Plugin/Action/Title.php(44): _drupal_error_handler(2, 'Undefined prope...', '/app/web/module...', 44)
#2 /app/web/modules/contrib/eca/src/Entity/Objects/EcaAction.php(102): Drupal\eca_base\Plugin\Action\Title->execute(NULL)
#3 /app/web/modules/contrib/eca/src/Processor.php(188): Drupal\eca\Entity\Objects\EcaAction->execute(Object(Drupal\eca\Entity\Objects\EcaAction), Object(Drupal\eca_form\Event\FormBuild), Array)
#4 /app/web/modules/contrib/eca/src/Processor.php(190): Drupal\eca\Processor->executeSuccessors(Object(Drupal\eca\Entity\Eca), Object(Drupal\eca\Entity\Objects\EcaAction), Object(Drupal\eca_form\Event\FormBuild), Array)
#5 /app/web/modules/contrib/eca/src/Processor.php(146): Drupal\eca\Processor->executeSuccessors(Object(Drupal\eca\Entity\Eca), Object(Drupal\eca\Entity\Objects\EcaEvent), Object(Drupal\eca_form\Event\FormBuild), Array)
#6 /app/web/modules/contrib/eca/src/EventSubscriber/EcaBase.php(76): Drupal\eca\Processor->execute(Object(Drupal\eca_form\Event\FormBuild), 'eca.form.build')
#7 [internal function]: Drupal\eca\EventSubscriber\EcaBase->onEvent(Object(Drupal\eca_form\Event\FormBuild), 'eca.form.build', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#8 /app/web/core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php(111): call_user_func(Array, Object(Drupal\eca_form\Event\FormBuild), 'eca.form.build', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#9 /app/web/modules/contrib/eca/src/Event/TriggerEvent.php(73): Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object(Drupal\eca_form\Event\FormBuild), 'eca.form.build')
#10 /app/web/modules/contrib/eca/modules/form/src/HookHandler.php(47): Drupal\eca\Event\TriggerEvent->dispatchFromPlugin('form:form_build', Array, Object(Drupal\Core\Form\FormState))
#11 /app/web/modules/contrib/eca/modules/form/eca_form.module(25): Drupal\eca_form\HookHandler->alter(Array, Object(Drupal\Core\Form\FormState))
#12 /app/web/core/lib/Drupal/Core/Extension/ModuleHandler.php(545): eca_form_form_alter(Array, Object(Drupal\Core\Form\FormState), 'taxonomy_term_r...')
#13 /app/web/core/lib/Drupal/Core/Form/FormBuilder.php(840): Drupal\Core\Extension\ModuleHandler->alter('form', Array, Object(Drupal\Core\Form\FormState), 'taxonomy_term_r...')
#14 /app/web/core/lib/Drupal/Core/Form/FormBuilder.php(284): Drupal\Core\Form\FormBuilder->prepareForm('taxonomy_term_r...', Array, Object(Drupal\Core\Form\FormState))
#15 /app/web/core/lib/Drupal/Core/Entity/EntityFormBuilder.php(48): Drupal\Core\Form\FormBuilder->buildForm(Object(Drupal\taxonomy\TermForm), Object(Drupal\Core\Form\FormState))
#16 /app/web/core/modules/taxonomy/src/Controller/TaxonomyController.php(26): Drupal\Core\Entity\EntityFormBuilder->getForm(Object(Drupal\taxonomy\Entity\Term))
#17 [internal function]: Drupal\taxonomy\Controller\TaxonomyController->addForm(Object(Drupal\taxonomy\Entity\Vocabulary))
#18 /app/web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(123): call_user_func_array(Array, Array)
#19 /app/web/core/lib/Drupal/Core/Render/Renderer.php(592): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
#20 /app/web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(124): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure))
#21 /app/web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(97): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array)
#22 /app/vendor/symfony/http-kernel/HttpKernel.php(181): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
#23 /app/vendor/symfony/http-kernel/HttpKernel.php(76): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1)
#24 /app/web/core/lib/Drupal/Core/StackMiddleware/Session.php(58): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#25 /app/web/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(48): Drupal\Core\StackMiddleware\Session->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#26 /app/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(106): Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#27 /app/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(85): Drupal\page_cache\StackMiddleware\PageCache->pass(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#28 /app/web/core/modules/ban/src/BanMiddleware.php(50): Drupal\page_cache\StackMiddleware\PageCache->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#29 /app/web/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(48): Drupal\ban\BanMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#30 /app/web/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(51): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#31 /app/web/core/lib/Drupal/Core/StackMiddleware/StackedHttpKernel.php(51): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#32 /app/web/core/lib/Drupal/Core/DrupalKernel.php(704): Drupal\Core\StackMiddleware\StackedHttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#33 /app/web/index.php(19): Drupal\Core\DrupalKernel->handle(Object(Symfony\Component\HttpFoundation\Request))
#34 {main}

That sounds like you're using ECA 1.1 on production, while this patch only works with the 2.0.x release.

@VladimirAus Any chance to address my questions in #6?

@jurgenhaas Yep, I'm planning to address it in the coming weeks.
No ETA though, sorry.

@VladimirAus are you coming to DrupalCon Portland? We could then probably address this there.

@VladimirAus hope you don't mind a friendly ping.

Still here. Stuck in a rut of Drupal 11 and then jumping on this guy.
@jurgenhaas feel free to ping me.

Ping ;-)

I've rebased the MR to the latest dev branch. @VladimirAus maybe this is an issue to be addressed in Singapor?

Ping

There is a "hidden" layer of how a page title can be set.

There is an anoymous function in Drupal\Core\Render\MainContent\HtmlRenderer::prepare:

<?php
    $get_title = function (array $main_content) use ($request, $route_match) {
      return $main_content['#title'] ?? $this->titleResolver->getTitle($request, $route_match->getRouteObject());
    };
?>

It fetches the #title key from the main page content render array and uses it when set.
For example, within Drupal\node\NodeForm::form the page title of the node edit page is being set as follows:

<?php
    if ($this->operation == 'edit') {
      $form['#title'] = $this->t('<em>Edit @type</em> @title', [
        '@type' => node_get_type_label($node),
        '@title' => $node->label(),
      ]);
    }
?>

We could make use of this mechanism, by implementing "Set Title" as a render action so that it is able to get the current render array. Then we are probably able to set the title for example on a "Build form" event.

@mxh that sounds interesting, I just wonder where we get the render array from. Does that require an extra event for when the page gets rendered?

Would it otherwise be possible to decorate the \Drupal\Core\Block\Plugin\Block\PageTitleBlock plugin?

There is a listener Drupal\Core\EventSubscriber\MainContentViewSubscriber::onViewRenderArray on event Symfony\Component\HttpKernel\KernelEvents::VIEW. Within that listener method, following happens:

// For main page content controller methods, this can (but is not forced to be) returning a renderable array.
$result = $event->getControllerResult();
// ...
$renderer = $this->classResolver->getInstanceFromDefinition($this->mainContentRenderers[$wrapper]);
// $wrapper == 'html' -> will be calling \Drupal\Core\Render\MainContent\HtmlRenderer::renderResponse
$response = $renderer->renderResponse($result, $request, $this->routeMatch);
// ...

There is an already existing "kernel:view" event plugin in eca_misc. It could be extended to reckognize $result = $event->getControllerResult(); so in case of a renderable array, it could be instantiated as a Drupal\eca\Event\RenderEventInterface.

This sounds great, should be worth a try.