.. toctree:: :maxdepth: 2
Jivago provides its own reflection-style registration mechanism. We will define as annotations decorators which do not alter the decorated functions or classes but add a means of programmatically inspecting said decorated functions or classes.
Accessing annotated elements is done by interrogating the Registry object. Two types of annotations are defined in Jivago :
- Annotation: A general-purpose registering decorator.
- ParametrizedAnnotation: Allows the passing of arguments when the annotation is used.
The Registry object contains references to all annotated elements, and provides a get_annotated_in_package method, which returns all registrations for a specific annotation, for which the package name starts with the given string. Below is an example where all classes with the @Component annotation in any package are requested.
.. literalinclude:: registry.py :language: python
Standard annotations can be defined using either the python-esque decorator-style syntax by adding the @Annotation decorator to a simple pass-through decorator, or the simpler object-style syntax by invoking the Annotation constructor.
.. literalinclude:: annotations.py :language: python
Parametrized annotations can only defined using the decorator-style syntax. To create a new parametrized annotation, use the @ParametrizedAnnotation decorator on a function which returns a pass-through function. (See the example below.)
Unnamed argument will be saved in the dictionary with the declared parameter name as the key.
.. literalinclude:: parametrized_annotations.py :language: python