An in-depth presentation of the eZ Platform view layer, built around Symfony's MVC stack.

1. 1
The eZ Platform
View Layer
Bertrand Dunogier Platform Lead bd@ez.no @bdunogier
This presentation is online: bdunogier.github.io/talks/ezconf2016-ezplatform-views

2. 2
About me
11th year at eZ, 13th year around it
Platform backend lead engineer
Focused on REST & Symfony layers

3. 3
Plan
I. The View Layer
II. Changes in Platform 1.x
II. Query types
V. The Query Controller
V. Using the View layer in your projects

4. 4 . 1
The View Layer
A layer that wraps around Symfony's MVC. For a given route, it loads a
Value and renders it. It is mainly used to render content using UrlAliases
and ez_content:viewAction.
The template and controller can be customized using view configuration:
ezpublish:
system:
site:
content_view:
full:
article:
template: 'content/view/full/article.html.twig'
controller: 'app.article_controller:viewArticleAction'
match:
IdentifierContentType: 'article'

5. 4 . 2
How it worked in eZ Publish 5.x
Two types of views: location_view and content_view.
public function showArticleAction( $locationId, $viewType, $layout = false, array $params = array
{
return $this->get( 'ez_content' )->viewLocation(
$locationId,
$viewType,
$layout,
['some_variable' => 'some_value'] + $params
);
}

6. 4 . 3
Drawbacks
Requires complex calls
Error prone
Tight coupling with the extended view controller, complex BC

7. 4 . 4

8. 4 . 5
What has changed in Platform 1.x
location_view is deprecated, and only content_view should be
used**.
Custom controllers do not need to inherit from a built-in one anymore.
namespace AppBundleController;
class ArticleController
{
public function viewArticleAction(ContentView $view)
{
$view->addParameters(['some_value' => 'whatever']);
return $view;
}
}
Parameters will be made available in the view template.

9. 5 . 1
Query types
Added in eZ Platform 1.x.
They are named Query factories that support parameters, and can be
registered either by naming convention, or using a service tag.
$query = $queryType->getQuery(['paramName' => $paramValue]);
$searchService->findLocations($query);

10. 5 . 2
Use-case: LocationChildren query type
A QueryType that builds a LocationQuery searching for children of a given
location id.
In addition to the parentLocationId parameter, it optionally accepts
limit and offset:
$query = $queryType->getQuery(['parentLocationId' => 2, 'limit' => 5]);
$searchService->findLocations($query);

11. 5 . 3
LocationChildren QueryType structure
All QueryTypes must implement the
eZPublishCoreQueryTypeQueryType interface, that has three
methods:
namespace AppBundleQueryType;
class LocationChildrenQueryType implements QueryType
{
public function getQuery(array $parameters = []): Query
public function getSupportedParameters(): array
public static function getName(): string
}

12. 5 . 4
The getSupportedParameters() method
Returns the supported parameters names.
public function getSupportedParameters()
{
return ['parentLocationId', 'offset', 'limit'];
}

13. 5 . 5
The getName static method
Returns the name of the QueryType.
public function getName()
{
return 'app.location_children';
}
(Thank you Mr. Obvious)

14. 5 . 6
The getQuery() method
Called to build the Query
Receives the build parameters
Returns the Query object
public function getQuery(array $parameters = [])
{
return new LocationQuery([
'filter' => new CriterionParentLocationId($parameters['parentLocationId']),
'offset' => $parameters['offset'] ?: 0,
'limit' => $parameters['limit'] ?: 10,
]);
}

15. 5 . 7
Using QueryTypes from PHP
inject a QueryType using its service
use the ezpublish.query_type.registry service

16. 6 . 1
The Query controller
A built-in view controller that runs a Query from a QueryType, and assigns
the results to the view.
It supports mapping of viewed content/location properties to QueryType
parameters.

17. Usage example
ezpublish:
system:
site:
content_view:
full:
gallery:
template: 'content/view/full/gallery.html.twig'
controller: 'ez_query:locationQueryAction'
params:
query:
query_type: app.location_children
parameters:
parentLocationId: @=location.id
assign_results_to: images
The SearchResult object is assigned to the 'images' twig variable:
{% for searchResult in images.searchHits %}
{{ render( controller(
'ez_content:viewAction',

18. 6 . 2
{'content': searchResult.valueObject, 'viewType': 'embed'}
) }}
{% endfor %}

19. 6 . 3
Conclusion
And questions maybe ?

20. 7 . 1
Custom Views
The View layer can be re-used in order to allow customization of reusable
components.
I. A value object to view (ex: SystemInfo)
II. A View object (ex: SystemInfoView)
II. A very short controller (ex: SystemInfoController)
V. A ViewBuilder (ex: SystemInfoViewBuilder)

21. 7 . 2
The Value
Can be any value object
Will be made available in the view templates
Loaded from the ViewBuilder, using route parameters

22. 7 . 3
The View object
Must implement the View interface
May implement the BaseView class
Instantiated by the ViewBuilder
May implement other View interfaces to add Matchers support
Examples: ContentValueView, LocationValueView

23. 7 . 4
The ViewBuilder
Must implement the ViewBuilder interface
Must be registered with the ezpublish.view_builder.registry
Manual registration for now, using a compiler pass / DIC extension
Uses the matched controller's name to filter requests
Must call a ViewConfigurator to apply templates & controller
configuration

24. 7 . 5
Custom matchers
Allows custom business rules for view matching.
Example: ViewMatcherSystemInfoIdentifier.
Requires a custom ViewProvider and ViewMatcherFactory.
Examples: support_tools.view.system_info.provider and
support_tools.view.matcher_factory in view.yml.

25. 7 . 6
Optional: View configuration
Siteaccess aware, semantic view configuration.
Requirements:
a ConfigParser. Example: SystemInfoViewParser
injection into the ezpublish extension, if you want it below

26. 7 . 7
Improvements possibilities
DX:
matchers
view providers
view configuration

27. 8
Conclusion & Questions