Services: The Backbone of Everything

Hey John,

Yeah, most of core objects you type hint with an interface that the real object extends. Mostly, that's done for flexibility, as you can pass any object that extends that interface (Symfony has many objects which are wrapped with another object). And finally, that's just a good OOP concept when you typhint with interfaces instead of end objects if you have them. For your own objects it's redundant to add interfaces if you don't have benefits from it, but from some third-party services it has more sense as most of them already implement some interfaces, extend some base cases, etc.

But for you, to know how to typehint - you can leverage Symfony's bin/console debug:autowiring command that will show you what exactly type-hint and variable name you need to use to inject a proper service/object.

I hope it helps!

Cheers!

Hey @John-S,

Great question!

In practice, I typically always use controller method injection but it really comes down to personal/project/team preference. I find controllers easier to read when all their requirements are injected into the method.

sorry. deleted.(not sure if needed because you mention this in next chapter. pls delete if not needed). Deleted post:

Two different ways of injecting logger service.

1.

class TestController
{

private $logger;
public function __construct(LoggerInterface $logger)
{
    $this->logger = $logger;
}

}
2.

class TestController
{

public function test1(LoggerInterface $logger)
{   
}
public function test2(LoggerInterface $logger)
{   
}

}
I intend to use logger in several methods but not all of them. Should i use constructor injection or inject it in every method ?

Hey @Mahmut-A!

Great question! There's no web debug toolbar because this is a json response. The toolbar can only be shown on html responses.

There's still a way you can see the profile for this request though! All requests, regardless of the response type, are saved. After making a request to /api/starships visit /_profiler. You should see a list of recent requests - you can even search them! Find the one to /api/starships and click the token. That will be the full profile for
that request.

Hope that help!

--Kevin

Hey @Jaime-Garcia

It depends on your local PHP installation and the system you use for development. It asks you to install a php-intl extension to PHP

If you provide more details on you system and PHP installataion then I can provide you more detail help.

Cheers

Hi, sorry for the time spent on answering, I have windows 11 and php on 8.3.12 (cli) (NTS Visual C++ 2019 x64)

as I see, it's a windows php version, not a WSL one, so you have to find php.ini and enable php-intl module there

Hey Ahmad,

Not sure about datadog but for example you can log into Loggly logs server. You can see the required config in the bundle's configuration file: https://github.com/symfony/monolog-bundle/blob/06ddd76fd24dcf325a61e826b5c799e4b929422e/DependencyInjection/Configuration.php#L318-L322

There you can search for other log platforms there like rollbar, etc.

Cheers!

Hey Mahmut,

Autowiring helps you to inject services with type-hints, i.e. in your action you can literally write the typehint of the class or interface from the debug:autowiring command output and the system will inject that service into your action, e.g.:

class ProductController()
{
    public function show(CacheInterface $cache)
    {
        // the $cache will be an instance of CacheInterface
        // that was autowired in this action thanks to autowiring
    }
}

That's so simple. As long as a service is listed in the debug:autowiring output - it will be able to typehint this way in your controller actions or __construct() methods of our services.

How can you know the service name? That's a good question! Well, first of all, you probably should base on the documentation, either official Symfony docs or bundle's docs in case you're going to use a service from a bundle. Or, you can just "guess" it, like if you need a cache search, just search something like "cache" in the output and see if you have any matches. But mostly, I would recommend you to base on docs in the beginning, unless you get used to already known services and will know exactly what to look for.

I hope it's clearer for you now!

Cheers!

thank you Victor. I will add something:
for example serializer is a service. I am doing. ./bin/console debug:autowiring serialize and there are aliases in output.
I also saw this service id in debug:container. However, I could not find related class information in bundless.php.

for example, below is outpu of autowiring serialize. what is class to be seen in bundles.php? how can ı detect it?

thank you

The following classes & interfaces can be used as type-hints when autowiring:
(only showing classes/interfaces matching serialize)

Symfony\Component\Messenger\Transport\Serialization\SerializerInterface - alias:messenger.transport.native_php_serializer

Symfony\Component\Serializer\Encoder\DecoderInterface - alias:serializer

Symfony\Component\Serializer\Encoder\EncoderInterface - alias:serializer

Hey Mahmut,

Don't forget that extra services may come not only from bundles but only from pure PHP packages called Symfony components. Components are not bundles, they do not contain any configuration. For example that Serializer component's configuration is come from the core FrameworkBundle that is installed but default in our Symfony app, but the actual classes are available only after you install the component with Composer.

But as I already said, if you're not sure - please, better check the docs instead of guessing, that's the easiest and fastest way probably :)

Cheers!

Hey @Ernest-H

These nice icons are from https://plugins.jetbrains.com/plugin/10044-atom-material-icons IIRC

Thanks for the feedback. Cheers and happy coding!

Hi @Inforob,

Yeah that's a good point. This file was mentioned in the chapter 5 of this course, and as it was said previously in most cases you will not edit it manually, every installed bundle will be registered there with proper env activation param depending on how you installed it and recipes system configuration. Of course on custom bundles you will need to choose how to activate them.

Cheers!