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 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): from .utils import csrf_input_lazy, csrf_token_lazy 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(): with open(exception_file, 'r') as fp: source = fp.read() 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, }