We will start by going through the various ways to find and retrieve content from eZ Publish using the API. While this will be covered in further dedicated documentation, it is necessary to explain a few basic concepts of the Public API. In the following recipes, you will learn about the general principles of the API as they are introduced in individual recipes.
Displaying values from a Content
In this recipe, we will see how to fetch a Content instance from the repository, and obtain its Field's content.
Let's first see the full code. You can see the Command line version at https://github.com/ezsystems/CookbookBundle/blob/master/EzSystems/CookBookBundle/Command/ViewContentCommand.php.
Let's analyze this code block by block.
This is the initialization part. As explained above, everything in the Public API goes through the repository via dedicated services. We get the repository from the service container, using the method
get() of our container, obtained via
$this->getContainer(). Using our $repository variable, we fetch the two services we will need using
Everything starting from line 5 is about getting our Content, and iterating over its Fields. You can see that the whole logic is part of a
try/catch block. Since the Public API uses Exceptions for error handling, this is strongly encouraged, as it will allow you to conditionally catch the various errors that may happen. We will cover the exceptions we expect in a next paragraph.
The first thing we do is use the Content Service to load a Content using its ID, 66:
( 66 ). As you can see on the API doc page, this method expects a Content ID, and returns a Content Value Object.
This block is the one that actually displays the value.
It iterates over the Content's (Content Object) fields using the ContentType's (Content Class) FieldDefinitions (Content Class Attribute) (
For each Field Definition (Content Class Attribute), we start by displaying its identifier (
$fieldDefinition->identifier). We then get the FieldType (Datatype) instance using the FieldType Service (
$fieldTypeService->getFieldType( $fieldDefinition->fieldTypeIdentifier )). This method expects the requested FieldType's identifier, as a string (ezstring, ezxmltext...), and returns an
The Field object (Content Object Attribute) is obtained using the
getField() method of the Content Value Object we obtained using
Using this FieldType object, we can convert the Field's value to a hash using the
toHash() method, provided by every FieldType. This method returns a native type (string, hash) out of a Field instance.
With this example, you should get a first idea on how you interact with the API. Everything is done through services, each service being responsible for a specific part of the repository (Content, FieldType, etc).
Loading Content in different languages
Since we didn't specify any language code, our Field objects is returned in the default language, depending on your language settings in
ezpublish.yml. If you want to use a non-default language, you can specify a language code in the
As said earlier, the Public API uses Exceptions to handle errors. Each method of the API may throw different exceptions, depending on what it does. Which exceptions can be thrown is usually documented for each method. In our case,
loadContent() may throw two type of exceptions:
NotFoundException if the requested ID wasn't found, and
UnauthorizedException if the currently logged in user isn't allowed to view the requested content.
It is a good practice to cover each exception you expect to happen. In this case, since our Command takes the content ID as a parameter, this ID may either not exist, or the referenced content may not be visible to our user. Both cases are covered with explicit error messages.
Traversing a Location subtree
This recipe will show how to traverse a Location's subtree. The full code implements a command that takes a Location ID as an argument, and recursively prints this location's subtree.
As for the ContentService,
loadLocation() returns a Value Object, here a
Location. Errors are handled with exceptions:
NotFoundException if the Location ID couldn't be found, and
UnauthorizedException if the current repository user isn't allowed to view this location.
Note that unlike loadLocation(), we don't need to care for permissions here: the currently logged in user's permissions will be respected when loading children, and locations that can't be viewed won't be returned at all.
Should you need more advanced children fetching methods, the
SearchService is what you are looking for.
Viewing Content Meta Data
Content is a central piece in the Public API. You will often need to start from a Content, and dig in from its metadata. Content metadata is made available through
ContentInfo objects. This Value Object mostly provides primitive metadata:
The full example implements an
ezpublish:cookbook:view_content_metadata command that prints out all the available metadata given a content ID.
Setting the repository user
In a command line script, the repository runs as if executed by the anonymous user. In order to identify as a different user, you need to use the
UserService as follows:
This may be crucial when writing maintenance or synchronization scripts.
This is of course not required in template functions or controller code, as the HTTP layer will take care of identifying the user, and automatically set it in the repository.
The code will load a
ContentInfo object using the provided ID, and use
Performing a simple full text search
In this recipe a simple full text search is performed. (Full code here)
Performing an advanced search
In this recipe different criteria is combined using a logic 'AND' operation. The result is restricted additional (see recipe 9) to a given content type and subtree. (Full code here)