WIP Jinja support.

src/reactpy_django/templatetags/jinja.py

@@ -0,0 +1,57 @@
+# Copyright © 2023 Innovatie Ltd. All rights reserved.
+"""
+Jinja support.
+"""
+import typing as t
+
+from jinja2 import pass_context
+from jinja2.ext import Extension
+from jinja2.runtime import Context, Undefined
+
+
+class ReactPyExtension(Extension):
+    """
+    Jinja has more expressive power than core Django's templates, and can
+    directly handle expansions such as:
+
+        {{ component(*args, **kwargs) }}
+    """
+    #
+    # Therefore, there is no new tag to parse().
+    #
+    tags = {}
+
+    def __init__(self, environment):
+        super().__init__(environment)
+        #
+        # All we need is to add global "component" to the environment.
+        #
+        environment.globals["component"] = self._component
+
+    @pass_context
+    def _component(self, __context: Context, implementation: str, *args: t.Any,
+                   **kwargs: t.Any) -> t.Union[t.Any, Undefined]:
+        """
+        This method is used to embed an existing ReactPy component into your
+        Jinja2 template.
+
+        Args:
+            implementation: String of the fully qualified name of a component.
+            *args:          The component's positional arguments.
+            **kwargs:       The component's keyword arguments.
+
+        Returns:
+            Whatever the components returns.
+        """
+        module, name = implementation.rsplit('.', 1)
+        component = getattr(__import__(module, None, None, [name]), name)
+        template_args = component(*args, **kwargs).render()
+        #
+        # TODO: template_args looks like this:
+        #
+        #   {'tagName': 'h1', 'children': ['Hello World!']}
+        #
+        # and need to be run through the Django template in
+        # templates/reactpy/component.html, or equivalent.
+        #
+        return template_args