Add native Jinja2 extension for DRF template rendering (#4084)

pyproject.toml

@@ -66,6 +66,7 @@ optional = [
   "django-filter",
   "django-guardian>=2.4.0,<3.4",
   "inflection==0.5.1",
+  "jinja2>=3.0",
   "legacy-cgi; python_version>='3.13'",
   "markdown>=3.3.7",
   "psycopg[binary]>=3.1.8",

rest_framework/jinja2.py

@@ -0,0 +1,25 @@
+from jinja2.ext import Extension
+
+from rest_framework.renderers import HTMLFormRenderer
+
+
+class DRFExtension(Extension):
+    """Jinja2 extension exposing DRF template rendering functions."""
+
+    def __init__(self, environment):
+        super().__init__(environment)
+        environment.globals["render_form"] = self.render_form
+        environment.globals["render_field"] = self.render_field
+
+    def render_form(self, serializer, style=None):
+        """Render a complete HTML form for the given serializer."""
+        renderer = HTMLFormRenderer()
+        return renderer.render(
+            serializer.data,
+            renderer_context={"serializer": serializer, "style": style or {}},
+        )
+
+    def render_field(self, field, style=None):
+        """Render an individual HTML field."""
+        renderer = HTMLFormRenderer()
+        return renderer.render_field(field, style or {})

tests/test_jinja2_templates.py

@@ -0,0 +1,66 @@
+import importlib
+
+import pytest
+
+from rest_framework import serializers
+
+
+def load_jinja():
+    pytest.importorskip("jinja2")
+    jinja2 = importlib.import_module("jinja2")
+    DRFExtension = importlib.import_module("rest_framework.jinja2").DRFExtension
+    return jinja2.Environment, DRFExtension
+
+
+class SimpleSerializer(serializers.Serializer):
+    name = serializers.CharField()
+    age = serializers.IntegerField()
+
+
+def test_jinja2_render_form_with_extension():
+    """
+    Test that the DRF Jinja2 extension correctly exposes render_form
+    and render_field to the Jinja2 environment.
+    """
+    Environment, DRFExtension = load_jinja()
+
+    # Setup Jinja2 environment with the new DRF extension
+    env = Environment(extensions=[DRFExtension])
+
+    # Create a template that uses the DRF rendering functions
+    template_str = """
+    {% set form_data = render_form(serializer) %}
+    {{ form_data }}
+    """
+    template = env.from_string(template_str)
+
+    serializer = SimpleSerializer(data={"name": "Mohammed", "age": 30})
+    serializer.is_valid()
+
+    # Render the template
+    output = template.render(serializer=serializer)
+
+    # Assertions: Verify the output contains expected HTML form elements
+    assert (
+        "<form" in output or "name" in output.lower()
+    ), "Expected form rendering to contain field data"
+    assert "Mohammed" in output, "Expected rendered form to contain the serializer data"
+
+
+def test_jinja2_render_field_individual():
+    """
+    Test that render_field works individually in Jinja2.
+    """
+    Environment, DRFExtension = load_jinja()
+    env = Environment(extensions=[DRFExtension])
+    template_str = "{{ render_field(serializer.name) }}"
+    template = env.from_string(template_str)
+
+    serializer = SimpleSerializer(data={"name": "Ahmed", "age": 25})
+    serializer.is_valid()
+
+    output = template.render(serializer=serializer)
+
+    assert (
+        "Ahmed" in output or "name" in output.lower()
+    ), "Expected field rendering to work"