This document is not meant to be a comprehensive guide to either Symfony 2 or eZ Publish 5, but to give an overview of how common concepts and tasks used in older versions translate into the new one.

Glossary

New names of existing concepts:

4.x

5.x

(Content) ClassContent Type
(Content) Class GroupContent Type Group
(Content) Class AttributeField Definition
(Content) Object

Content (Meta info in: Content Info)

(Content Object) VersionVersion Info

(Content Object) Attribute

Field

(Content Object) Attribute contentField Value

Datatype

Field Type

Node

Location

The reason for renaming some of the concepts in eZ Publish 5.x was to use terms which might be more familiar to users coming from other CMS and avoid confusion with terms used in OOP programming.

New concepts:

You can also refer to Symfony glossary page as many of the following concepts are the same or taken from Symfony.

5.x

Description

Controller

An OOP version of what was called "module" in 4.x, should extend eZ\Bundle\EzPublishCoreBundle\Controller.
A good start is to read Symfony documentation on this topic

Action

The method on the Controller, similarly to what was referred to as "view" in 4.x, contains business logic bootstrap (business logic should be done in services).

ViewThe template that displays the result of the "action", can be either .twig (default) or .php.
Note that Twig is highly recommended as it has eZ Publish specific helpers. 
ServiceA Service is a generic term for any PHP object that performs a specific task and thus contains business logic. Services are instantiated and maintained a the service container.
Service ContainerA Service Container, also known as a Dependency Injection Container, is a special object that manages the instantiation of services inside an application. Instead of creating services directly, the developer trains the service container (via configuration) on how to create the services.
See Symfony documentation on the service container
RenderA function that allows you to Embed other controller calls, as in Hierarchically render other controllers and embed it in your result. This effectively removes the need for having business logic in template using fetch functions, session management and so on.

Bundle

An "extension" in Symfony Framework and hence the extensions of eZ Publish 5.x kernel.

Consoleezpublish/console is the starting point of all console commands in Symfony2 (referred to as app/console in Symfony2 documentation) and eZ Publish 5.x kernel, use php ezpublish/console -h from the root of your install using command line to get started.
web/

The public folder of your site, two console commands exists to symlink/hard-copy Bundles and Legacy assets respectively.
Front controllers (index.php/index_dev.php) can be modified to fit your needs. 

ezpublish/The application folder (aka app/ in the Symfony documentation).
It contains the main Kernel class where you can declare the bundles you want to use. You will also find cache/, logs/ and main config/ folders. It can also contain application-level resource files, such as global templates (ezpublish/Resources/).
src/This is where your application code stands (from your own bundles)
vendor/In this directory stand all your dependencies (3rd party bundles/libs, eZ Publish codebase, Symfony codebase...)

Existing concepts FAQ

Settings

Siteaccesses

Q: Apart from host url and port, are any other matchers available (host+url, …)

A: working on an improved fleximatcher witch will be part of 5.1, this includes host+uri combined matching

Urls

Q: How is the siteaccess part of urls managed (standard Sf code has no concept for this)?

A: The eZP stack uses an enhanced router. This is transparent to developers.

Q: Support for linking across siteaccess?

A: Not yet possibly in 5.0.

Designs

Q: How is the concept of designs + fallback supported ?

A: Planned for 5.future. Might reuse an Sf bundle from Liip which allows themes (theme == design).

Templates (twig)

i18n

Refer to the translation section in Symfony documentation.

Loading css, js

Best practice is to use Assetic.

Caching

Content cache is fully Http cache.

Q: How to clear caches for eZ Publish 5? Is there a single action to clear caches for both stacks?

A: Content (Http) cache is purged at publish time or from admin interface. You can use the cache:clear command to clear all Symfony cache. No unified command yet.

4-in-5

Q: Will it always be possible to run the Legacy Stack as a standalone app? 

A: Yes.

Q: Is there any rewrite rule needed to access var/storage/images of old stack from within the vhost of the new stack?

A: No, this is achieved by symlinking to web/ the design/, extension/, share/ and var/ directories of the eZ Publish legacy stack (done via ezpublish:legacy:assets_install script).

The official name for the eZ Publish 4.x stack included within eZ Publish 5.x is not eZ Publish 4.x but eZ Publish Legacy (+"Stack" in case of eZ Publish+extensions).

Extensions

Q: Implemented as bundles?

A: Yes.

 

Q: Declared as services with a special tag or naming convention? (see e.g. How twig registers stuff).

A: Reuse as much as possible from Sf, do not enforce standards unless needed.

 

Q: Will need naming convention?

 

Q: Installed via composer?

A: Yes.

 

Q: What part of a website to put in ezpublish/, what part to put in src/? (equivalent of eZ “all in extension” dev philosophy)

A: ezpublish/ is for global configuration/templates, src/ is for site-specific developments.

Q: Best practices for naming php classes (filenames and directories)?

A: Follow PSR-0, with namespaces.
    See http://symfony.com/doc/2.0/cookbook/bundles/best_practices.html

Debugging

$logger = $this->get('logger');
$logger->info('We just got the logger');
$logger->err('An error occurred');

Testing

Refer to Symfony documentation on testing and PHPUnit.