phparchitect-2019-08

http://www.phparch.com \ August 2019 \ 5

Symfony 4: A New Way to Develop Applications

Symfony Flex FTW!

Let’s first talk a little bit about
Symfony Flex^7 , a Composer plugin. It
can be required with one command.

composer require symfony/flex

It’s a real plug-and-play feature for
Symfony and Composer. Flex installs
the package you want and does some
additional things. Typically, these are
the steps you needed to do manually in
the past. Symfony Flex was the compo-
nent that was missing. Composer
should have been a tool that allowed
you to easily add or remove bundles
(like plugins) from your application.
However, we were doing all of these
steps manually—adding configurations,
removing configurations, etc. With
Symfony Flex, we don’t need to do this,
the goal is to have zero-configuration,
and it works.

Symfony Flex is a Composer plugin
that modifies the behavior of the
require, update, and remove commands.
When installing or removing depen-
dencies in a Flex-enabled application,
Symfony can perform tasks before
and after the execution of Composer
tasks. Symfony Flex plays a huge role in
providing better DX. As I stated before,
and we see later, you start with almost
nothing, and you only add things
when needed. Symfony Flex allows us
to add third-party bundles as plug-
and-play plugins (add if you needed it
and remove it when you don’t need it)
without any additional configuration
(Figure 2).

After you run composer require,
Symfony Flex asks Symfony Flex
server^8 if there is a recipe or any addi-
tional information about the installed
package. If there is no information or
no recipe, nothing happens, and you do
the configuration manually as before. If
recipes exist, the server answers with
yes and sends the recipes. Composer
reads the recipes and executes all the
steps defined inside the recipe.

7 Symfony Flex: https://flex.symfony.com
8 Flex server:
https://phpa.me/symfony-setup-flex

In Listing 1, we can see a simple

recipe for SwiftmailerBundle^9. On the

first line, it tells Symfony Flex how to

enable the bundle in the configuration.

The copy-from-recipe line specifies

which configuration files need to be

copied to the Symfony project config-

uration. Later, we discuss the new

directory structure and a new way of

configuration in Symfony 4. There

are two repositories related to recipes.

The Symfony core team maintains a

Symfony/recipes^10 repository, and they

guarantee the quality of the compo-

nents. Only these recipes can use an

alias. An alias is a name which you

can use with Composer require, so in

this case composer require mailer or

composer require mail give the same

9 SwiftmailerBundle:

https://phpa.me/swiftmailer-manifest

10 Symfony/recipes:

https://github.com/symfony/recipes

results. Symfony.sh is the site where you

can get a list of all recipes.

Starting a New Project With

Symfony 4

There are a few ways to start a

new Symfony project. You can use

Composer, or you can use the Symfony

client^11. The Symfony client is a potent

tool, and I recommend using it. It helps

you:

1. Create new Symfony applications.
   2. Provide a local HTTP/2 web server.
   3. Generate TLS certificates.
   4. Check for security vulnerabilities.
   5. Seamlessly integrate with
   SymfonyCloud^12.

11 Symfony client:

https://symfony.com/download

12 SymfonyCloud:

https://symfony.com/cloud/

Listing 1

1. {


2. "bundles": {


3. "Symfony\Bundle\SwiftmailerBundle\SwiftmailerBundle": ["all"]


4. },


5. "copy-from-recipe": {


6. "config/": "%CONFIG_DIR%/"


7. },


8. "env": {


9. "#1": "For Gmail as a transport, use:
   \"gmail://username:password@localhost\"",


10. "#2": "For a generic SMTP server, use:
    \"smtp://localhost:25?encryption=&auth_mode=\"",


11. "#3": "Delivery is disabled by default via \"null://localhost\"",


12. "MAILER_URL": "null://localhost"


13. },


14. "aliases": ["mailer", "mail"]


15. }

Figure 2