Problem:
I tried to register a CustomErrorRenderer on Symfony 5 to render my CustomException, but all the time the TwigErrorRenderer is called. I thought probably self-defined renderers might be preferred?
CustomErrorRenderer.php:
namespace App\ErrorRenderer;
use Symfony\Component\ErrorHandler\Exception\FlattenException;
use Symfony\Component\ErrorHandler\ErrorRenderer\ErrorRendererInterface;
class CustomErrorRenderer implements ErrorRendererInterface
{
public function render(\Throwable $exception): FlattenException
{
dd('CustomErrorRenderer.render() called');
// TODO check if CustomException, else refer to preset renderer...
}
}
services.yaml:
services:
App\ErrorRenderer\CustomErrorRenderer:
tags: ['error_renderer.renderer']
# also tried: ['error_renderer.renderer', 'error_renderer.html','error_handler.error_renderer' , 'error_handler.error_renderer.html']
What is wrong with that?
Background:
I have a web application and want to handle exceptions that are related to my internal business logic separately. E.g., a user wants to book a resource but it is currently not available. While current errors/exceptions are handled by the TwigErrorRenderer (or default HtmlErrorRenderer), I would like to add my own Renderer (ideally just extending the TwigErrorRenderer, so that I can use some specific, self-defined twig templates). By that, I aim to have a better UI, e.g., my custom exceptions being rendered while still the menu of the web application is shown. As my exceptions are not related to how the data is accessed (e.g. http), I do not want to use HttpExceptions and their status code.
This was not particularly easy to figure out.
I made a copy of vendor/symfony/twig-bridge/ErrorRenderer/TwigErrorRenderer.php into my app src\CustomerErrorRenderer.php.
Then override the error_renderer in services.yaml:
services:
error_renderer:
class: App\CustomErrorRenderer
arguments: ['#twig', '#error_handler.error_renderer.html','%kernel.debug%']
Of course, that's not exactly how they call in their code when I tried to test using /_error/404 for instance.
They actually use arguments more like:
error_renderer:
class: App\Twig\CustomErrorRenderer
arguments:
- '#twig'
- '#error_handler.error_renderer.html'
- !service
factory: [ 'Symfony\Component\ErrorHandler\ErrorRenderer\HtmlErrorRenderer', 'getAndCleanOutputBuffer' ]
arguments: ['#request_stack']
Related
How is it possible to use Symfony\Component\EventDispatcher\EventSubscriberInterface to implement a subscriber-class, listening for events dispatched by TYPO3s PSR-14 EventDispatcher?
Let's see an example by using symfony/workflow for a TYPO3 extension, which works great until it comes to events. Because of typo3/symfony-psr-event-dispatcher-adapter, the TYPO3 default EventDispatcher can be smoothly added to the Workflow class. So far so good.
Now I've several problems:
Problem 1: The event-names such as 'workflow.myname.leave'
The events dispatched by Workflow using a string name, instead of a FQCN like all other events dispatched in the TYPO3 life-cycle. This makes it impossible to use the common way of EventListeners registered inside the services.yaml, because the configuration requires a FQCN of the event-class.
# this will not work because the "event" needs to be a FQCN
Vendor\MyExt\EventListener\MyWorkflowEventListener:
tags:
- name: event.listener
identifier: 'vendor-myext/MyWorkflowEventListener'
event: 'workflow.myname.leave'
method: 'onLeave'
Problem 2: Trying to use an EventSubscriber
The doc recomments an EventSubscriber. IMO using an EventSubscriber (Symfony\Component\EventDispatcher\EventSubscriberInterface) would also solve problem #1, because the configuration of events is defined as key-value array inside getSubscribedEvents(). (BTW this seems to be also much easier for lots of events like in this case of workflow-events, because one class can be responsible handling multiple "similar" events and will not mess-up the services.yaml).
Also the Symfony doc says, that implementing this interface while autowire and autoconfigure is set to true will be enough; the EventSubscriber should be available and listening. Maybe this is true in a plain Symfony environment, but it seems not in a context of TYPO3. Unfortunately I can't figure out why (the subscriber classes doesn't show up inside EventDispatcher->ListenerProvider->listeners array).
How to continue here?
The TYPO3 core EventDispatcher is not able to handle or register Subscribers (yet). So for now I ended up using the Symfony\Component\EventDispatcher\EventDispatcher in parallel to the TYPO3 default one. The Symfony EventDispatcher handles only the workflow-events in this case. It feels not as clean as I'd like to, but it works.
For those of you that are familiar with the building of the Symfony container, do you know what is the differences (if any) between
Tagged service Collector using a Compiler pass
Tagged service Collector using the supported shortcut
Service Locator especially, one that collects services by tags
Specifically, I am wondering about whether these methods differ on making these collected services available sooner or later in the container build process. Also I am wondering about the ‘laziness’ of any of them.
It can certainly be confusing when trying to understand the differences. Keep in mind that the latter two approaches are fairly new. The documentation has not quite caught up. You might actually consider making a new project and doing some experimenting.
Approach 1 is basically an "old school" style. You have:
class MyCollector {
private $handlers = [];
public function addHandler(MyHandler $hamdler) {
$handlers[] = $handler;
# compiler pass
$myCollectorDefinition->addMethodCall('addHandler', [new Reference($handlerServiceId)]);
So basically the container will instantiate MyCollector then explicitly call addHandler for each handler service. In doing so, the handler services will be instantiated unless you do some proxy stuff. So no lazy creation.
The second approach provides a somewhat similar capability but uses an iterable object instead of a plain php array:
class MyCollection {
public function __construct(iterable $handlers)
# services.yaml
App\MyCollection:
arguments:
- !tagged_iterator my.handler
One nice thing about this approach is that the iterable actually ends up connecting to the container via closures and will only instantiate individual handlers when they are actually accessed. So lazy handler creation. Also, there are some variations on how you can specify the key.
I might point out that typically you auto-tag your individual handlers with:
# services.yaml
services:
_instanceof:
App\MyHandlerInterface:
tags: ['my.handler']
So no compiler pass needed.
The third approach is basically the same as the second except that handler services can be accessed individually by an index. This is useful when you need one out of all the possible services. And of course the service selected is only created when you ask for it.
class MyCollection {
public function __construct(ServiceLocator $locator) {
$this->locator = $locator;
}
public function doSomething($handlerKey) {
/** #var MyHandlerInterface $handler */
$handler = $serviceLocator->get($handlerKey);
# services.yaml
App\MyCollection:
arguments: [!tagged_locator { tag: 'app.handler', index_by: 'key' }]
I should point out that in all these cases, the code does not actually know the class of your handler service. Hence the var comment to keep the IDE happy.
There is another approach which I like in which you make your own ServiceLocator and then specify the type of object being located. No need for a var comment. Something like:
class MyHandlerLocator extends ServiceLocator
{
public function get($id) : MyHandlerInterface
{
return parent::get($id);
}
}
The only way I have been able to get this approach to work is a compiler pass. I won't post the code here as it is somewhat outside the scope of the question. But in exchange for a few lines of pass code you get a nice clean custom locator which can also pick up handlers from other bundles.
There is part of code in FOSElasticaExtension Extension class
$Def = new DefinitionDecorator('foo');
$Def->replaceArgument(0, $bar);
$Def->addTag('baz', array( 'name' => $qux, ));
$Def->setFactory(array(new Reference('quux'), 'corge'));
so in yaml it might look like this:
services:
foo:
arguments:
- '$bar'
tags:
- { name: baz }
factory: ["#quux", corge]
Why set factory in DefinitionDecorator instead of set new class with calls: directive?
services:
foo:
arguments:
- '$bar'
tags:
- { name: baz }
class: #quux
calls: corge
Can you please write a code example how you would expect it to look like? I don't really get the point of your question.
To generically answer why it's done like this you have to understand how Symfony compiles the service container. The service container has a huge impact on performance that's why it's compiled after the tree is completely built, which is after instantiating all the extensions. That also means that your extension doesn't really have the classes, but only references to classes. I assume the index class is not registered as a service and that's why it must be retrieved via the registered client service which is used as a factory. I hope this answers your question, if not feel free to expand your question or add a comment.
edit: That is an interesting question. I checked Symfony's DependencyInjection, but from a cursory glance I can't find how exactly both approaches are different. From checking DefinitionTest I assume it's possible to do something like:
$def->setMethodCalls(array(array($factoryReference,'getIndex')));
which looks a bit more complicated. This might be why setFactory was preferred.
I have a service that needs to access the current application base URL (what's returned by app.request.getBaseURL() in Twig views). Currently, my config is like this:
services:
WidgetModel:
class: AppBundle\Model\WidgetModel
scope: prototype
arguments: ['%widgets%']
So as a second argument, I would like to inject the base URL. Is it possible? If not, what would be proper solution?
As far as I know there is no builtin base url service. Which is actually a bit of a red flag that maybe having your component depending on it might not be such a good idea. But I can't think of a good reason why.
So normally, one would just inject the request object. But that has it's own problems as documented here: http://symfony.com/blog/new-in-symfony-2-4-the-request-stack
Instead, inject the #request_stack service and pull the url from it:
class WidgetModel
{
public __construct($widgets,$requestStack)
{
$this->baseUrl = $requestStack->getCurrentRequest()->getBaseUrl();
If you do find yourself needing the baseUrl in multiple services then you could define your own factory type service to generate it. But again, that might mean your design needs rethinking.
You can use the expression language in your service definition.
This example should do what you want:
services:
WidgetModel:
class: AppBundle\Model\WidgetModel
scope: prototype
arguments: [%widgets%, "#=service('request').getBaseUrl()"]
It fetches the request service and then executes the getBaseUrl method.
You will need to add a second parameter in your WigetModel for the base URL.
To complete the answer, in Symfony 3 you can use request_stack to get the base url using expressions languages (updated link) such as:
services:
WidgetModel:
class: AppBundle\Model\WidgetModel
scope: prototype
arguments: [%widgets%,"#=service('request_stack').getCurrentRequest().getBaseUrl()"
I got a problem to add custom logic to some Symfony classes.
SwitchUserListener
I want to add a check, that a user cannot switch to a another user, which have more rights/roles, than the initial user.
First attempt
Overwrite the parameter in the security_listeners.xml with the key:
security.authentication.switchuser_listener.class But where can I overwrite it?
In the security.yml it didn't work:
security:
...
authentication:
switchuser_listener:
class: Symfony\Component\Security\Http\Firewall\SwitchUserListener
Second attempt
Overwrite the service for the SwitchUserListner service id: security.authentication.switchuser_listener
I create the same service in my service.xml of my bundle, but my class was not used / called.
Another idea was to overwrite only the class, but that only works for bundles, but the SwitchUserListener was not in the SecurityBundle, it was in the symfony component directory and that seemed to me as a really bad idea to overwrite the SecurityBundle
Third attempt
Now I get the solution: First time I didn't realize that the dispatcher call listener for the SWTICH_USER event in the SwitchUserListener:
$switchEvent = new SwitchUserEvent($request, $token->getUser());
$this->dispatcher->dispatch(SecurityEvents::SWITCH_USER, $switchEvent);
So I need only to create a service with the special tag for this event type:
<tag name="kernel.event_listener" event="security.switch_user" method="onSecuritySwitchUser" />
And do the check in the given method.
This seems to be a better solution thatn the other two. But there is still a problem. In my listener for the SwitchUserEvent I need to ignore my custom check if the user wants to exit the switched user.
So I need to check the requested path: ignore if path containts '?switch_user=_exit'
But the path (URL parameter) can be changed:
# app/config/security.yml
security:
firewalls:
main:
# ...
switch_user: { role: ROLE_ADMIN, parameter: _want_to_be_this_user }
But in my bundle I can't read this parameter, because it will not be passed to the service container. It will be passed to the constructor of the SwitchUserListner class and will be saved there as private attribute, never accessable (without Reflection) from outside. (that happens here: SecurityExtension.php line 591) So what to do? Define the parameter twice go against DRY. Use Reflection?
And the other point is that there aren' every time events that will be fired on which I write a subscriber class. So what would be another / best solution for it?
I ask this question because I will get some similar problem where I want to add or overwrite something of the symfony intern components.
TemplateGuesser
I wanted to modify the TemplateGuesser: For a specific bundle all Templates which has the annotation #Tempalte the tempate file should be located with the controller TestController#showAction at this path:
Resources/views/customDir/Test/show.html.twig
So the guesser should be put and locate everything into a additional folder customDir instead of using only views. When using the render function with a specific template, the guesser should ignore the annotation.
I created my own Guesser and overwrite the service id: sensio_framework_extra.view.guesser and in comparision to the SwitchUserListener this time my class is really called instead of the original guesser. Why it works here but not with the SwitchUserListener?
Is this a good solution at all? I also tried to add a second listener, which calls the TemplateGuesser, its the service sensio_framework_extra.view.listener with the class Sensio\Bundle\FrameworkExtraBundle\EventListener\TemplateListener But that didn't work.
Whenever you need to add custom logic or extend the framework behaviour, you can use and abuse the container configuration. That means you can overwrite pretty much every service Symfony defines by just creating a new class that extends that service – or not, really – and creating the service definition for it with the same key as the original service you wanted to extend or change behaviour.
For instance, Symfony has a base template guesser registered as a service with the sensio_framework_extra.view.guesser id. If you want to extend that or change behaviour, you only need to create your own class and register it with the same id of the original service – remember that the bundles loading order affects the service definitons with the same id, where the last one loaded is the one that will be created.
That should solve both of your problems.