django/tests/template_tests/test_response.py

import pickle
import time
from datetime import datetime

from django.template import engines
from django.template.response import (
    ContentNotRenderedError,
    SimpleTemplateResponse,
    TemplateResponse,
)
from django.test import (
    RequestFactory,
    SimpleTestCase,
    modify_settings,
    override_settings,
)
from django.test.utils import require_jinja2

from .utils import TEMPLATE_DIR


def test_processor(request):
    return {"processors": "yes"}


test_processor_name = "template_tests.test_response.test_processor"


# A test middleware that installs a temporary URLConf
def custom_urlconf_middleware(get_response):
    def middleware(request):
        request.urlconf = "template_tests.alternate_urls"
        return get_response(request)

    return middleware


class SimpleTemplateResponseTest(SimpleTestCase):
    def _response(self, template="foo", *args, **kwargs):
        template = engines["django"].from_string(template)
        return SimpleTemplateResponse(template, *args, **kwargs)

    def test_template_resolving(self):
        response = SimpleTemplateResponse("first/test.html")
        response.render()
        self.assertEqual(response.content, b"First template\n")

        templates = ["foo.html", "second/test.html", "first/test.html"]
        response = SimpleTemplateResponse(templates)
        response.render()
        self.assertEqual(response.content, b"Second template\n")

        response = self._response()
        response.render()
        self.assertEqual(response.content, b"foo")

    def test_explicit_baking(self):
        # explicit baking
        response = self._response()
        self.assertFalse(response.is_rendered)
        response.render()
        self.assertTrue(response.is_rendered)

    def test_render(self):
        # response is not re-rendered without the render call
        response = self._response().render()
        self.assertEqual(response.content, b"foo")

        # rebaking doesn't change the rendered content
        template = engines["django"].from_string("bar{{ baz }}")
        response.template_name = template
        response.render()
        self.assertEqual(response.content, b"foo")

        # but rendered content can be overridden by manually
        # setting content
        response.content = "bar"
        self.assertEqual(response.content, b"bar")

    def test_iteration_unrendered(self):
        # unrendered response raises an exception on iteration
        response = self._response()
        self.assertFalse(response.is_rendered)

        def iteration():
            list(response)

        msg = "The response content must be rendered before it can be iterated over."
        with self.assertRaisesMessage(ContentNotRenderedError, msg):
            iteration()
        self.assertFalse(response.is_rendered)

    def test_iteration_rendered(self):
        # iteration works for rendered responses
        response = self._response().render()
        self.assertEqual(list(response), [b"foo"])

    def test_content_access_unrendered(self):
        # unrendered response raises an exception when content is accessed
        response = self._response()
        self.assertFalse(response.is_rendered)
        with self.assertRaises(ContentNotRenderedError):
            response.content
        self.assertFalse(response.is_rendered)

    def test_content_access_rendered(self):
        # rendered response content can be accessed
        response = self._response().render()
        self.assertEqual(response.content, b"foo")

    def test_set_content(self):
        # content can be overridden
        response = self._response()
        self.assertFalse(response.is_rendered)
        response.content = "spam"
        self.assertTrue(response.is_rendered)
        self.assertEqual(response.content, b"spam")
        response.content = "baz"
        self.assertEqual(response.content, b"baz")

    def test_dict_context(self):
        response = self._response("{{ foo }}{{ processors }}", {"foo": "bar"})
        self.assertEqual(response.context_data, {"foo": "bar"})
        response.render()
        self.assertEqual(response.content, b"bar")

    def test_kwargs(self):
        response = self._response(
            content_type="application/json", status=504, charset="ascii"
        )
        self.assertEqual(response.headers["content-type"], "application/json")
        self.assertEqual(response.status_code, 504)
        self.assertEqual(response.charset, "ascii")

    def test_args(self):
        response = SimpleTemplateResponse("", {}, "application/json", 504)
        self.assertEqual(response.headers["content-type"], "application/json")
        self.assertEqual(response.status_code, 504)

    @require_jinja2
    def test_using(self):
        response = SimpleTemplateResponse("template_tests/using.html").render()
        self.assertEqual(response.content, b"DTL\n")
        response = SimpleTemplateResponse(
            "template_tests/using.html", using="django"
        ).render()
        self.assertEqual(response.content, b"DTL\n")
        response = SimpleTemplateResponse(
            "template_tests/using.html", using="jinja2"
        ).render()
        self.assertEqual(response.content, b"Jinja2\n")

    def test_post_callbacks(self):
        "Rendering a template response triggers the post-render callbacks"
        post = []

        def post1(obj):
            post.append("post1")

        def post2(obj):
            post.append("post2")

        response = SimpleTemplateResponse("first/test.html", {})
        response.add_post_render_callback(post1)
        response.add_post_render_callback(post2)

        # When the content is rendered, all the callbacks are invoked, too.
        response.render()
        self.assertEqual(response.content, b"First template\n")
        self.assertEqual(post, ["post1", "post2"])

    def test_pickling(self):
        # Create a template response. The context is
        # known to be unpicklable (e.g., a function).
        response = SimpleTemplateResponse(
            "first/test.html",
            {
                "value": 123,
                "fn": datetime.now,
            },
        )
        with self.assertRaises(ContentNotRenderedError):
            pickle.dumps(response)

        # But if we render the response, we can pickle it.
        response.render()
        pickled_response = pickle.dumps(response)
        unpickled_response = pickle.loads(pickled_response)

        self.assertEqual(unpickled_response.content, response.content)
        self.assertEqual(
            unpickled_response.headers["content-type"], response.headers["content-type"]
        )
        self.assertEqual(unpickled_response.status_code, response.status_code)

        # ...and the unpickled response doesn't have the
        # template-related attributes, so it can't be re-rendered
        template_attrs = ("template_name", "context_data", "_post_render_callbacks")
        for attr in template_attrs:
            self.assertFalse(hasattr(unpickled_response, attr))

        # ...and requesting any of those attributes raises an exception
        for attr in template_attrs:
            with self.assertRaises(AttributeError):
                getattr(unpickled_response, attr)

    def test_repickling(self):
        response = SimpleTemplateResponse(
            "first/test.html",
            {
                "value": 123,
                "fn": datetime.now,
            },
        )
        with self.assertRaises(ContentNotRenderedError):
            pickle.dumps(response)

        response.render()
        pickled_response = pickle.dumps(response)
        unpickled_response = pickle.loads(pickled_response)
        pickle.dumps(unpickled_response)

    def test_pickling_cookie(self):
        response = SimpleTemplateResponse(
            "first/test.html",
            {
                "value": 123,
                "fn": datetime.now,
            },
        )

        response.cookies["key"] = "value"

        response.render()
        pickled_response = pickle.dumps(response, pickle.HIGHEST_PROTOCOL)
        unpickled_response = pickle.loads(pickled_response)

        self.assertEqual(unpickled_response.cookies["key"].value, "value")

    def test_headers(self):
        response = SimpleTemplateResponse(
            "first/test.html",
            {"value": 123, "fn": datetime.now},
            headers={"X-Foo": "foo"},
        )
        self.assertEqual(response.headers["X-Foo"], "foo")


@override_settings(
    TEMPLATES=[
        {
            "BACKEND": "django.template.backends.django.DjangoTemplates",
            "DIRS": [TEMPLATE_DIR],
            "OPTIONS": {
                "context_processors": [test_processor_name],
            },
        }
    ]
)
class TemplateResponseTest(SimpleTestCase):
    factory = RequestFactory()

    def _response(self, template="foo", *args, **kwargs):
        self._request = self.factory.get("/")
        template = engines["django"].from_string(template)
        return TemplateResponse(self._request, template, *args, **kwargs)

    def test_render(self):
        response = self._response("{{ foo }}{{ processors }}").render()
        self.assertEqual(response.content, b"yes")

    def test_render_with_requestcontext(self):
        response = self._response("{{ foo }}{{ processors }}", {"foo": "bar"}).render()
        self.assertEqual(response.content, b"baryes")

    def test_context_processor_priority(self):
        # context processors should be overridden by passed-in context
        response = self._response(
            "{{ foo }}{{ processors }}", {"processors": "no"}
        ).render()
        self.assertEqual(response.content, b"no")

    def test_kwargs(self):
        response = self._response(content_type="application/json", status=504)
        self.assertEqual(response.headers["content-type"], "application/json")
        self.assertEqual(response.status_code, 504)

    def test_args(self):
        response = TemplateResponse(
            self.factory.get("/"), "", {}, "application/json", 504
        )
        self.assertEqual(response.headers["content-type"], "application/json")
        self.assertEqual(response.status_code, 504)

    @require_jinja2
    def test_using(self):
        request = self.factory.get("/")
        response = TemplateResponse(request, "template_tests/using.html").render()
        self.assertEqual(response.content, b"DTL\n")
        response = TemplateResponse(
            request, "template_tests/using.html", using="django"
        ).render()
        self.assertEqual(response.content, b"DTL\n")
        response = TemplateResponse(
            request, "template_tests/using.html", using="jinja2"
        ).render()
        self.assertEqual(response.content, b"Jinja2\n")

    def test_pickling(self):
        # Create a template response. The context is
        # known to be unpicklable (e.g., a function).
        response = TemplateResponse(
            self.factory.get("/"),
            "first/test.html",
            {
                "value": 123,
                "fn": datetime.now,
            },
        )
        with self.assertRaises(ContentNotRenderedError):
            pickle.dumps(response)

        # But if we render the response, we can pickle it.
        response.render()
        pickled_response = pickle.dumps(response)
        unpickled_response = pickle.loads(pickled_response)

        self.assertEqual(unpickled_response.content, response.content)
        self.assertEqual(
            unpickled_response.headers["content-type"], response.headers["content-type"]
        )
        self.assertEqual(unpickled_response.status_code, response.status_code)

        # ...and the unpickled response doesn't have the
        # template-related attributes, so it can't be re-rendered
        template_attrs = (
            "template_name",
            "context_data",
            "_post_render_callbacks",
            "_request",
        )
        for attr in template_attrs:
            self.assertFalse(hasattr(unpickled_response, attr))

        # ...and requesting any of those attributes raises an exception
        for attr in template_attrs:
            with self.assertRaises(AttributeError):
                getattr(unpickled_response, attr)

    def test_repickling(self):
        response = SimpleTemplateResponse(
            "first/test.html",
            {
                "value": 123,
                "fn": datetime.now,
            },
        )
        with self.assertRaises(ContentNotRenderedError):
            pickle.dumps(response)

        response.render()
        pickled_response = pickle.dumps(response)
        unpickled_response = pickle.loads(pickled_response)
        pickle.dumps(unpickled_response)

    def test_headers(self):
        response = TemplateResponse(
            self.factory.get("/"),
            "first/test.html",
            {"value": 123, "fn": datetime.now},
            headers={"X-Foo": "foo"},
        )
        self.assertEqual(response.headers["X-Foo"], "foo")


@modify_settings(
    MIDDLEWARE={"append": ["template_tests.test_response.custom_urlconf_middleware"]}
)
@override_settings(ROOT_URLCONF="template_tests.urls")
class CustomURLConfTest(SimpleTestCase):
    def test_custom_urlconf(self):
        response = self.client.get("/template_response_view/")
        self.assertContains(response, "This is where you can find the snark: /snark/")


@modify_settings(
    MIDDLEWARE={
        "append": [
            "django.middleware.cache.FetchFromCacheMiddleware",
            "django.middleware.cache.UpdateCacheMiddleware",
        ],
    },
)
@override_settings(
    CACHE_MIDDLEWARE_SECONDS=2, ROOT_URLCONF="template_tests.alternate_urls"
)
class CacheMiddlewareTest(SimpleTestCase):
    def test_middleware_caching(self):
        response = self.client.get("/template_response_view/")
        self.assertEqual(response.status_code, 200)

        time.sleep(1.0)

        response2 = self.client.get("/template_response_view/")
        self.assertEqual(response2.status_code, 200)

        self.assertEqual(response.content, response2.content)

        time.sleep(2.0)

        # Let the cache expire and test again
        response2 = self.client.get("/template_response_view/")
        self.assertEqual(response2.status_code, 200)

        self.assertNotEqual(response.content, response2.content)