The PHP API is also commonly referred to as the "Public API". Currently it exposes a Repository which allows you to create, read, update, manage and delete all objects available in eZ Platform, first and foremost content, but also related objects like Sections, Locations, Content Types, Content Type groups, languages and so on.
This entity is the entry point to everything you will do with the Public API.
It will allow you to create, retrieve, update and delete all the eZ Platform objects, as well as Content Types, Sections, Content states. It is always obtained through the service container.
By itself, the repository doesn't do much. It allows three types of operations: user authentication (getting / changing the current user), issuing transactions, and obtaining services.
The above code snippet implies that the service container is available in the context you are writing your code in.
In controllers, this generally is done by extending the Symfony
Controller
class. It comes with a
get()
method that calls the service container. In command line scripts, it requires that you extend the ContainerAwareCommand base class instead of Controller. This class provides you with a getContainer() method that returns the service container.
One of the responsibilities of the Repository is user authentication. Every action will be executed as a user. In the context of a normal eZ Platform execution, the logged in user will of course be the current one, identified via one of the available authentication methods. This user's permissions will affect the behavior of the Repository. The user may for example not be allowed to create Content, or view a particular Section.
Logging in to the Repository is covered in other recipes of the Cookbook.
The main entry point to the repository's features are services. The Public API breaks down access to Content, User, Content Types and other features into various services. Those services are obtained via the Repository, using get[ServiceName]() methods:
getContentService()
,
getUserService()
, etc.
Throughout the Cookbook, you will be guided through the various capabilities those services have, and how you can use them to implement your projects.
While Services provide interaction with the repository, the elements (Content, Users) they provide interaction with are provided as read-only Value Objects in the eZ\Publish\Core\Repository\Values namespace. Those objects are broken down into sub-namespaces: Content, ContentType, User and ObjectState, each sub-namespace containing a set of value objects, such as Content\Content or User\Role .
These objects are read-only by design. They are only meant to be used in order to fetch data from the repository. They come with their own properties, such as $content->id, $location->hidden, but also with methods that provide access to more related information, such as Relation::getSourceContentInfo() or Role::getPolicies(). By design, a value object will only give you access to data that is very closely related to it. More complex retrieval operations will require you to use the appropriate Service, using information from your Value Object.
Some complex Value Objects have an Info counterpart, like ContentInfo, the counterpart for Content. These objects are specific and provide you with lower-level information. For instance, ContentInfo will provide you with currentVersionNo or remoteId, while Content will let you retrieve Fields, the Content Type, or previous Versions.
They are provided by the API, but are read only, can't be modified and sent back. Creation and modification of Repository values is done using Create structs and Update structs.
In order to update or create elements in the Repository, you will use structs. They are usually provided by the Service that manages the Value Objects you want to alter or create. For instance, the Content service has a getContentCreateStruct() method that returns a new ContentCreateStruct object. Equivalent methods exist for UpdateStruct objects as well, and for most Value Objects.
Using them is also covered in the Cookbook.
