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Migrating framework Config

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Most of our old code lives in app/config, and also src/AppBundle. We'll talk about that directory later - it's easier.

Yep, most of the work of migrating our code to the new app involves moving each piece of config into the new location. Honestly, it's tedious and slow. But you're going to learn a lot, and the end result is totally worth it.

Moving Parameters

Start in config.yml. Ignore imports: we'll look at each file one-by-one. The first key is parameters. Copy those, delete them, and open config/services.yaml. This is where your parameters and services will live. Paste them here. Oh, but remove the strict_mode line: autowiring always works in "strict mode" in Symfony 4.

30 lines | config/services.yaml
// ... lines 1 - 2
locale: en
cache_type: file_system
// ... lines 6 - 30

Environment Variables

Keep going! Back to config.yml. The keys under framework will be the most work to migrate... by far. In Flex, this configuration will live in config/packages/framework.yaml: each package has its own config file.

Remove the esi line from the old file: it's also commented out in the new one: nothing to migrate.

Check out the secret config: it's set to %env(APP_SECRET)%. That's a relatively new syntax that reads from environment variables. In the dev environment, Symfony loads the .env file, which sets all these keys as environment variables, including APP_SECRET.

Delete the old secret key. The way this value is set is a bit different, but, the point is, it's handled.

Requiring translator

The next key is translator. Are you ready? Because this is where things get fun! You might think that all we need to do is copy this line into framework.yaml. But no!

Many of the keys under framework represent components. In Symfony 3, by adding the translator key, you activated that component.

But with Flex, the Translator component isn't even installed yet. Yep, if you want a translator, you need to install it. In your terminal, run:

composer require translator

If that package name looks funny... it should! There is no package called translator! But look! It added a new symfony/translator key to composer.json.

This is another superpower of Flex. Go to This is a list of all of the packages that have a recipe. Search for "translation" to find symfony/translation. See those Aliases? Yep, we can reference translation, translations or translator and Flex will, um, translate that into symfony/translator automatically.

The translator Recipe

Back to the terminal! Before I started recording, I committed all of our changes so far. That was no accident: Flex just installed a recipe and I want to see exactly what it did! Run:

git status

Cool! It created a new translation.yaml file and a translation/ directory.

default_locale: '%locale%'
- '%kernel.project_dir%/translations'
- '%locale%'

That is where translation files should live in Symfony 4. And even though the translator config lives under framework, in Flex, it has its own configuration file. Oh, and this is one of my favorite things about Flex. Why should my translation files live in a translations/ directory? Is that hardcoded somewhere deep in core? Nope: it's right here in your configuration file. Want to put them somewhere else? Just update that line or add a second path.

So, do we need to move the translator config from our old project? Actually, no! It's already in the new file. Delete it.

And since we now know that translations should live in this new translations/ directory, let's move our existing files... well file. In app/Resources/translations, move validators.en.yml down into translations/.

Migrating router Config

We're on a roll! What about the router config? It told Symfony to load routing.yml. All of that is taken care of in the new app: it loads a routes.yaml file and anything in the routes/ directory, like annotations.yaml.

There's also a config/packages/routing.yaml file, and even another one in dev/ to tweak that strict_requirements setting.

The point is this: routing is handled. Delete that stuff!

Migrating Forms and Validator

Next, forms! Like with translations, this activates a component that is not installed yet. We do have forms in our app, so we need this and validation. Let's get them installed:

composer require form validator

Yep! More aliases! Perfect! This time, it did not install any recipes. That's cool: not all packages need a recipe.

So, do we need to move these 2 lines of config into framework.yaml? Actually, no!

Go back to your terminal and run:

./bin/console debug:config framework

This prints out the current framework configuration. Search for form. Nice! It's already enabled, even without any config! This is really common with Flex: as soon as a component is installed, FrameworkBundle automatically enables it. No configuration is needed unless you want to change something. Delete the form line.

Search for "validation" next: it's even more interesting! It's also enabled, and enable_annotations is set to true. Great! Delete the validation line! What's really interesting is that enable_annotations is set to true because it detected that we have the Doctrine annotations package installed. This is the flow with Flex: install a package and you're done.

Ok! It might not look like it, but we're almost done with the framework stuff. Let's finish it next!