Annotations
Turbine provides a number of annotations to inject dependencies into your actions,
screens and layouts. All Assemblers
that is, all modules of type
Action
, Screen
, Layout
, Page
,
Navigation
and ScheduledJob
as well as all
Valves
in the pipeline support the injection of services,
configurations and loaders. This relieves you from the burden of looking
them up at runtime and thus simplifies and accelerates the code.
@TurbineService
The annotation can only be used with a field. A declared field in a class annotated with@TurbineService
gets injected an instance of this service at the time the instance
of the class is created. The field should have the type of the service
interface like in the following two examples:
// Explicit service name @TurbineService( "RunDataService" ) private RunDataService runDataService; // Implicit SERVICE_NAME or ROLE @TurbineService private FactoryService factory;
runDataService = (RunDataService) TurbineServices .getInstance().getService("RunDataService"); factory = (FactoryService) TurbineServices .getInstance().getService(FactoryService.ROLE);
SERVICE_NAME
and then ROLE
in the type class of the field to retrieve the service name. If none
of them can be found, the fully qualified class name of the
service interface is used to look up the service.
If the service instance cannot be found, the annotation processor will throw an exception.
@TurbineConfiguration
The annotation can only be used with a field. If a declared field of the typeConfiguration
is annotated
with @TurbineConfiguration
, Turbine will inject an instance
of the Turbine configuration object at the time the instance of the class
is created.
// Injected configuration instance @TurbineConfiguration private Configuration config; // Injected configuration subset instance @TurbineConfiguration( "action" ) private Configuration actionConfig;
config = Turbine.getConfiguration(); actionConfig = Turbine.getConfiguration().subset("action");
If other fields having simple types are annotated with
@TurbineConfiguration
, Turbine will inject the corresponding
configuration value. In this case, the annotation parameter defines the
configuration key and is required. Strings, Lists and most simple types
are supported. The value will only be set if the key is found in the
configuration, so that the field can be initialized with a default value.
// Injected configuration value @TurbineConfiguration( "module.cache" ) private boolean moduleCache = true; @TurbineConfiguration( "template.homepage" ) private String templateHomepage;
moduleCache = Turbine.getConfiguration().getBoolean("module.cache", true); templateHomepage = Turbine.getConfiguration().getString("template.homepage");
@TurbineLoader
The annotation can only be used with a field. A declared field in a class annotated with@TurbineLoader
gets injected an instance of the specified Loader
at
the time the instance of the class is created. The field should have
the type of the loader.
// Injected loader instance @TurbineLoader( Action.class ) private ActionLoader actionLoader;
actionLoader = TurbineAssemblerBroker.getLoader(Action.class);
@TurbineActionEvent
The annotation can only be used with a method. A method in a class annotated with@TurbineActionEvent
is associated to a named action event. The annotation parameter
is required and defines the name of the event. See the
Action Events Howto
for usage and examples.
Performance Considerations
It is important to note that the processing of the annotations at the time the module class is instantiated takes some time. It is therefore strongly recommended to re-use the module instances in a production environment by setting the configuration parametermodule.cache
to true
in
TurbineResources.properties
.