from pathlib import Path
import jinja2
from django.conf import settings
from django.template import TemplateDoesNotExist, TemplateSyntaxError
from django.utils.functional import cached_property
from django.utils.module_loading import import_string
from .base import BaseEngine
from .utils import csrf_input_lazy, csrf_token_lazy
[docs]
class Jinja2(BaseEngine):
app_dirname = "jinja2"
def __init__(self, params):
params = params.copy()
options = params.pop("OPTIONS").copy()
super().__init__(params)
self.context_processors = options.pop("context_processors", [])
environment = options.pop("environment", "jinja2.Environment")
environment_cls = import_string(environment)
if "loader" not in options:
options["loader"] = jinja2.FileSystemLoader(self.template_dirs)
options.setdefault("autoescape", True)
options.setdefault("auto_reload", settings.DEBUG)
options.setdefault(
"undefined", jinja2.DebugUndefined if settings.DEBUG else jinja2.Undefined
)
self.env = environment_cls(**options)
def from_string(self, template_code):
return Template(self.env.from_string(template_code), self)
def get_template(self, template_name):
try:
return Template(self.env.get_template(template_name), self)
except jinja2.TemplateNotFound as exc:
raise TemplateDoesNotExist(exc.name, backend=self) from exc
except jinja2.TemplateSyntaxError as exc:
new = TemplateSyntaxError(exc.args)
new.template_debug = get_exception_info(exc)
raise new from exc
@cached_property
def template_context_processors(self):
return [import_string(path) for path in self.context_processors]
class Template:
def __init__(self, template, backend):
self.template = template
self.backend = backend
self.origin = Origin(
name=template.filename,
template_name=template.name,
)
def render(self, context=None, request=None):
if context is None:
context = {}
if request is not None:
context["request"] = request
context["csrf_input"] = csrf_input_lazy(request)
context["csrf_token"] = csrf_token_lazy(request)
for context_processor in self.backend.template_context_processors:
context.update(context_processor(request))
try:
return self.template.render(context)
except jinja2.TemplateSyntaxError as exc:
new = TemplateSyntaxError(exc.args)
new.template_debug = get_exception_info(exc)
raise new from exc
class Origin:
"""
A container to hold debug information as described in the template API
documentation.
"""
def __init__(self, name, template_name):
self.name = name
self.template_name = template_name
def get_exception_info(exception):
"""
Format exception information for display on the debug page using the
structure described in the template API documentation.
"""
context_lines = 10
lineno = exception.lineno
source = exception.source
if source is None:
exception_file = Path(exception.filename)
if exception_file.exists():
source = exception_file.read_text()
if source is not None:
lines = list(enumerate(source.strip().split("\n"), start=1))
during = lines[lineno - 1][1]
total = len(lines)
top = max(0, lineno - context_lines - 1)
bottom = min(total, lineno + context_lines)
else:
during = ""
lines = []
total = top = bottom = 0
return {
"name": exception.filename,
"message": exception.message,
"source_lines": lines[top:bottom],
"line": lineno,
"before": "",
"during": during,
"after": "",
"total": total,
"top": top,
"bottom": bottom,
}
Sep 29, 2023