New in Symfony 4.4: Dependency Injection Improvements (Part 1)

Dumping the Container in One File

Contributed by Nicolas Grekas in #32581

Originally, Symfony container was compiled and dumped into a big PHP file. Then we changed it to allow dumping each service into its own small PHP file. In Symfony 4.4 we added a new configuration option to allow dumping the container again into a big single file.

This is enabled by default for all new Symfony applications, but you can also enable it for your existing applications inside the src/Kernel.php file:

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class Kernel extends BaseKernel
{
    // ...

    protected function configureContainer(ContainerBuilder $container, LoaderInterface $loader): void
    {
        // ...

        $container->setParameter('container.dumper.inline_factories', true);

        // ...
    }
}

Ignore Errors when Importing Files

Contributed by Andrej Hudec in #31310

When importing configuration files, you can use the ignore_errors: true option to silently ignore any missing files. However, this option also ignores files which exist but contain syntax errors. In Symfony 4.4 we've added a new value for this option so you ignore only missing files and not files with syntax errors:

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imports:
    # this will show an error if 'parameters.yaml' exists but contains syntax errors
    - { resource: 'parameters.yaml', ignore_errors: 'not_found' }

Allow Using Base64url Values in Env Vars

Contributed by Nicolas Grekas in #34014

Using standard Base64 in URL requires encoding of +, / and = characters. That's why the RFC 4648 defines a Base64 variant called Base64url which is safe for URLs and file names. Base64url replaces + by - and / by _ (and makes the trailing = optional).

In Symfony 4.4, we've improved the base64 env var processor to also allow parsing base64url values. You don't have to change anything in your code because Symfony can detect base64url values automatically and parse them for you.

Allow Binding Tagged Services

Contributed by Grégoire Pineau in #33623

Binding arguments by name or type allows to inject services and parameters based on the name and/or type of the service constructor arguments. In Symfony 4.4 you can also inject iterable and tagged services.

In the following example, the _instanceof config adds a tag to any services whose classes implement the given interface and the _defaults.bind config injects all those services in any iterable $rules constructor argument:

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# config/services.yaml
services:
    _instanceof:
        App\Foo\Rule\RuleInterface:
            tags: ['app.foo.rule']

    _defaults:
        bind:
            iterable $rules: !tagged_iterator app.foo.rule

    # ...