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1"""Classes for managing templates and their runtime and compile time
2options.
3"""
5import os
6import typing
7import typing as t
8import weakref
9from collections import ChainMap
10from functools import lru_cache
11from functools import partial
12from functools import reduce
13from types import CodeType
15from markupsafe import Markup
17from . import nodes
18from .compiler import CodeGenerator
19from .compiler import generate
20from .defaults import BLOCK_END_STRING
21from .defaults import BLOCK_START_STRING
22from .defaults import COMMENT_END_STRING
23from .defaults import COMMENT_START_STRING
24from .defaults import DEFAULT_FILTERS # type: ignore[attr-defined]
25from .defaults import DEFAULT_NAMESPACE
26from .defaults import DEFAULT_POLICIES
27from .defaults import DEFAULT_TESTS # type: ignore[attr-defined]
28from .defaults import KEEP_TRAILING_NEWLINE
29from .defaults import LINE_COMMENT_PREFIX
30from .defaults import LINE_STATEMENT_PREFIX
31from .defaults import LSTRIP_BLOCKS
32from .defaults import NEWLINE_SEQUENCE
33from .defaults import TRIM_BLOCKS
34from .defaults import VARIABLE_END_STRING
35from .defaults import VARIABLE_START_STRING
36from .exceptions import TemplateNotFound
37from .exceptions import TemplateRuntimeError
38from .exceptions import TemplatesNotFound
39from .exceptions import TemplateSyntaxError
40from .exceptions import UndefinedError
41from .lexer import get_lexer
42from .lexer import Lexer
43from .lexer import TokenStream
44from .nodes import EvalContext
45from .parser import Parser
46from .runtime import Context
47from .runtime import new_context
48from .runtime import Undefined
49from .utils import _PassArg
50from .utils import concat
51from .utils import consume
52from .utils import import_string
53from .utils import internalcode
54from .utils import LRUCache
55from .utils import missing
57if t.TYPE_CHECKING:
58 import typing_extensions as te
60 from .bccache import BytecodeCache
61 from .ext import Extension
62 from .loaders import BaseLoader
64_env_bound = t.TypeVar("_env_bound", bound="Environment")
67# for direct template usage we have up to ten living environments
68@lru_cache(maxsize=10)
69def get_spontaneous_environment(cls: t.Type[_env_bound], *args: t.Any) -> _env_bound:
70 """Return a new spontaneous environment. A spontaneous environment
71 is used for templates created directly rather than through an
72 existing environment.
74 :param cls: Environment class to create.
75 :param args: Positional arguments passed to environment.
76 """
77 env = cls(*args)
78 env.shared = True
79 return env
82def create_cache(
83 size: int,
84) -> t.Optional[t.MutableMapping[t.Tuple["weakref.ref[BaseLoader]", str], "Template"]]:
85 """Return the cache class for the given size."""
86 if size == 0:
87 return None
89 if size < 0:
90 return {}
92 return LRUCache(size) # type: ignore
95def copy_cache(
96 cache: t.Optional[
97 t.MutableMapping[t.Tuple["weakref.ref[BaseLoader]", str], "Template"]
98 ],
99) -> t.Optional[t.MutableMapping[t.Tuple["weakref.ref[BaseLoader]", str], "Template"]]:
100 """Create an empty copy of the given cache."""
101 if cache is None:
102 return None
104 if type(cache) is dict: # noqa E721
105 return {}
107 return LRUCache(cache.capacity) # type: ignore
110def load_extensions(
111 environment: "Environment",
112 extensions: t.Sequence[t.Union[str, t.Type["Extension"]]],
113) -> t.Dict[str, "Extension"]:
114 """Load the extensions from the list and bind it to the environment.
115 Returns a dict of instantiated extensions.
116 """
117 result = {}
119 for extension in extensions:
120 if isinstance(extension, str):
121 extension = t.cast(t.Type["Extension"], import_string(extension))
123 result[extension.identifier] = extension(environment)
125 return result
128def _environment_config_check(environment: "Environment") -> "Environment":
129 """Perform a sanity check on the environment."""
130 assert issubclass(
131 environment.undefined, Undefined
132 ), "'undefined' must be a subclass of 'jinja2.Undefined'."
133 assert (
134 environment.block_start_string
135 != environment.variable_start_string
136 != environment.comment_start_string
137 ), "block, variable and comment start strings must be different."
138 assert environment.newline_sequence in {
139 "\r",
140 "\r\n",
141 "\n",
142 }, "'newline_sequence' must be one of '\\n', '\\r\\n', or '\\r'."
143 return environment
146class Environment:
147 r"""The core component of Jinja is the `Environment`. It contains
148 important shared variables like configuration, filters, tests,
149 globals and others. Instances of this class may be modified if
150 they are not shared and if no template was loaded so far.
151 Modifications on environments after the first template was loaded
152 will lead to surprising effects and undefined behavior.
154 Here are the possible initialization parameters:
156 `block_start_string`
157 The string marking the beginning of a block. Defaults to ``'{%'``.
159 `block_end_string`
160 The string marking the end of a block. Defaults to ``'%}'``.
162 `variable_start_string`
163 The string marking the beginning of a print statement.
164 Defaults to ``'{{'``.
166 `variable_end_string`
167 The string marking the end of a print statement. Defaults to
168 ``'}}'``.
170 `comment_start_string`
171 The string marking the beginning of a comment. Defaults to ``'{#'``.
173 `comment_end_string`
174 The string marking the end of a comment. Defaults to ``'#}'``.
176 `line_statement_prefix`
177 If given and a string, this will be used as prefix for line based
178 statements. See also :ref:`line-statements`.
180 `line_comment_prefix`
181 If given and a string, this will be used as prefix for line based
182 comments. See also :ref:`line-statements`.
184 .. versionadded:: 2.2
186 `trim_blocks`
187 If this is set to ``True`` the first newline after a block is
188 removed (block, not variable tag!). Defaults to `False`.
190 `lstrip_blocks`
191 If this is set to ``True`` leading spaces and tabs are stripped
192 from the start of a line to a block. Defaults to `False`.
194 `newline_sequence`
195 The sequence that starts a newline. Must be one of ``'\r'``,
196 ``'\n'`` or ``'\r\n'``. The default is ``'\n'`` which is a
197 useful default for Linux and OS X systems as well as web
198 applications.
200 `keep_trailing_newline`
201 Preserve the trailing newline when rendering templates.
202 The default is ``False``, which causes a single newline,
203 if present, to be stripped from the end of the template.
205 .. versionadded:: 2.7
207 `extensions`
208 List of Jinja extensions to use. This can either be import paths
209 as strings or extension classes. For more information have a
210 look at :ref:`the extensions documentation <jinja-extensions>`.
212 `optimized`
213 should the optimizer be enabled? Default is ``True``.
215 `undefined`
216 :class:`Undefined` or a subclass of it that is used to represent
217 undefined values in the template.
219 `finalize`
220 A callable that can be used to process the result of a variable
221 expression before it is output. For example one can convert
222 ``None`` implicitly into an empty string here.
224 `autoescape`
225 If set to ``True`` the XML/HTML autoescaping feature is enabled by
226 default. For more details about autoescaping see
227 :class:`~markupsafe.Markup`. As of Jinja 2.4 this can also
228 be a callable that is passed the template name and has to
229 return ``True`` or ``False`` depending on autoescape should be
230 enabled by default.
232 .. versionchanged:: 2.4
233 `autoescape` can now be a function
235 `loader`
236 The template loader for this environment.
238 `cache_size`
239 The size of the cache. Per default this is ``400`` which means
240 that if more than 400 templates are loaded the loader will clean
241 out the least recently used template. If the cache size is set to
242 ``0`` templates are recompiled all the time, if the cache size is
243 ``-1`` the cache will not be cleaned.
245 .. versionchanged:: 2.8
246 The cache size was increased to 400 from a low 50.
248 `auto_reload`
249 Some loaders load templates from locations where the template
250 sources may change (ie: file system or database). If
251 ``auto_reload`` is set to ``True`` (default) every time a template is
252 requested the loader checks if the source changed and if yes, it
253 will reload the template. For higher performance it's possible to
254 disable that.
256 `bytecode_cache`
257 If set to a bytecode cache object, this object will provide a
258 cache for the internal Jinja bytecode so that templates don't
259 have to be parsed if they were not changed.
261 See :ref:`bytecode-cache` for more information.
263 `enable_async`
264 If set to true this enables async template execution which
265 allows using async functions and generators.
266 """
268 #: if this environment is sandboxed. Modifying this variable won't make
269 #: the environment sandboxed though. For a real sandboxed environment
270 #: have a look at jinja2.sandbox. This flag alone controls the code
271 #: generation by the compiler.
272 sandboxed = False
274 #: True if the environment is just an overlay
275 overlayed = False
277 #: the environment this environment is linked to if it is an overlay
278 linked_to: t.Optional["Environment"] = None
280 #: shared environments have this set to `True`. A shared environment
281 #: must not be modified
282 shared = False
284 #: the class that is used for code generation. See
285 #: :class:`~jinja2.compiler.CodeGenerator` for more information.
286 code_generator_class: t.Type["CodeGenerator"] = CodeGenerator
288 concat = "".join
290 #: the context class that is used for templates. See
291 #: :class:`~jinja2.runtime.Context` for more information.
292 context_class: t.Type[Context] = Context
294 template_class: t.Type["Template"]
296 def __init__(
297 self,
298 block_start_string: str = BLOCK_START_STRING,
299 block_end_string: str = BLOCK_END_STRING,
300 variable_start_string: str = VARIABLE_START_STRING,
301 variable_end_string: str = VARIABLE_END_STRING,
302 comment_start_string: str = COMMENT_START_STRING,
303 comment_end_string: str = COMMENT_END_STRING,
304 line_statement_prefix: t.Optional[str] = LINE_STATEMENT_PREFIX,
305 line_comment_prefix: t.Optional[str] = LINE_COMMENT_PREFIX,
306 trim_blocks: bool = TRIM_BLOCKS,
307 lstrip_blocks: bool = LSTRIP_BLOCKS,
308 newline_sequence: "te.Literal['\\n', '\\r\\n', '\\r']" = NEWLINE_SEQUENCE,
309 keep_trailing_newline: bool = KEEP_TRAILING_NEWLINE,
310 extensions: t.Sequence[t.Union[str, t.Type["Extension"]]] = (),
311 optimized: bool = True,
312 undefined: t.Type[Undefined] = Undefined,
313 finalize: t.Optional[t.Callable[..., t.Any]] = None,
314 autoescape: t.Union[bool, t.Callable[[t.Optional[str]], bool]] = False,
315 loader: t.Optional["BaseLoader"] = None,
316 cache_size: int = 400,
317 auto_reload: bool = True,
318 bytecode_cache: t.Optional["BytecodeCache"] = None,
319 enable_async: bool = False,
320 ):
321 # !!Important notice!!
322 # The constructor accepts quite a few arguments that should be
323 # passed by keyword rather than position. However it's important to
324 # not change the order of arguments because it's used at least
325 # internally in those cases:
326 # - spontaneous environments (i18n extension and Template)
327 # - unittests
328 # If parameter changes are required only add parameters at the end
329 # and don't change the arguments (or the defaults!) of the arguments
330 # existing already.
332 # lexer / parser information
333 self.block_start_string = block_start_string
334 self.block_end_string = block_end_string
335 self.variable_start_string = variable_start_string
336 self.variable_end_string = variable_end_string
337 self.comment_start_string = comment_start_string
338 self.comment_end_string = comment_end_string
339 self.line_statement_prefix = line_statement_prefix
340 self.line_comment_prefix = line_comment_prefix
341 self.trim_blocks = trim_blocks
342 self.lstrip_blocks = lstrip_blocks
343 self.newline_sequence = newline_sequence
344 self.keep_trailing_newline = keep_trailing_newline
346 # runtime information
347 self.undefined: t.Type[Undefined] = undefined
348 self.optimized = optimized
349 self.finalize = finalize
350 self.autoescape = autoescape
352 # defaults
353 self.filters = DEFAULT_FILTERS.copy()
354 self.tests = DEFAULT_TESTS.copy()
355 self.globals = DEFAULT_NAMESPACE.copy()
357 # set the loader provided
358 self.loader = loader
359 self.cache = create_cache(cache_size)
360 self.bytecode_cache = bytecode_cache
361 self.auto_reload = auto_reload
363 # configurable policies
364 self.policies = DEFAULT_POLICIES.copy()
366 # load extensions
367 self.extensions = load_extensions(self, extensions)
369 self.is_async = enable_async
370 _environment_config_check(self)
372 def add_extension(self, extension: t.Union[str, t.Type["Extension"]]) -> None:
373 """Adds an extension after the environment was created.
375 .. versionadded:: 2.5
376 """
377 self.extensions.update(load_extensions(self, [extension]))
379 def extend(self, **attributes: t.Any) -> None:
380 """Add the items to the instance of the environment if they do not exist
381 yet. This is used by :ref:`extensions <writing-extensions>` to register
382 callbacks and configuration values without breaking inheritance.
383 """
384 for key, value in attributes.items():
385 if not hasattr(self, key):
386 setattr(self, key, value)
388 def overlay(
389 self,
390 block_start_string: str = missing,
391 block_end_string: str = missing,
392 variable_start_string: str = missing,
393 variable_end_string: str = missing,
394 comment_start_string: str = missing,
395 comment_end_string: str = missing,
396 line_statement_prefix: t.Optional[str] = missing,
397 line_comment_prefix: t.Optional[str] = missing,
398 trim_blocks: bool = missing,
399 lstrip_blocks: bool = missing,
400 newline_sequence: "te.Literal['\\n', '\\r\\n', '\\r']" = missing,
401 keep_trailing_newline: bool = missing,
402 extensions: t.Sequence[t.Union[str, t.Type["Extension"]]] = missing,
403 optimized: bool = missing,
404 undefined: t.Type[Undefined] = missing,
405 finalize: t.Optional[t.Callable[..., t.Any]] = missing,
406 autoescape: t.Union[bool, t.Callable[[t.Optional[str]], bool]] = missing,
407 loader: t.Optional["BaseLoader"] = missing,
408 cache_size: int = missing,
409 auto_reload: bool = missing,
410 bytecode_cache: t.Optional["BytecodeCache"] = missing,
411 enable_async: bool = False,
412 ) -> "Environment":
413 """Create a new overlay environment that shares all the data with the
414 current environment except for cache and the overridden attributes.
415 Extensions cannot be removed for an overlayed environment. An overlayed
416 environment automatically gets all the extensions of the environment it
417 is linked to plus optional extra extensions.
419 Creating overlays should happen after the initial environment was set
420 up completely. Not all attributes are truly linked, some are just
421 copied over so modifications on the original environment may not shine
422 through.
424 .. versionchanged:: 3.1.2
425 Added the ``newline_sequence``,, ``keep_trailing_newline``,
426 and ``enable_async`` parameters to match ``__init__``.
427 """
428 args = dict(locals())
429 del args["self"], args["cache_size"], args["extensions"], args["enable_async"]
431 rv = object.__new__(self.__class__)
432 rv.__dict__.update(self.__dict__)
433 rv.overlayed = True
434 rv.linked_to = self
436 for key, value in args.items():
437 if value is not missing:
438 setattr(rv, key, value)
440 if cache_size is not missing:
441 rv.cache = create_cache(cache_size)
442 else:
443 rv.cache = copy_cache(self.cache)
445 rv.extensions = {}
446 for key, value in self.extensions.items():
447 rv.extensions[key] = value.bind(rv)
448 if extensions is not missing:
449 rv.extensions.update(load_extensions(rv, extensions))
451 if enable_async is not missing:
452 rv.is_async = enable_async
454 return _environment_config_check(rv)
456 @property
457 def lexer(self) -> Lexer:
458 """The lexer for this environment."""
459 return get_lexer(self)
461 def iter_extensions(self) -> t.Iterator["Extension"]:
462 """Iterates over the extensions by priority."""
463 return iter(sorted(self.extensions.values(), key=lambda x: x.priority))
465 def getitem(
466 self, obj: t.Any, argument: t.Union[str, t.Any]
467 ) -> t.Union[t.Any, Undefined]:
468 """Get an item or attribute of an object but prefer the item."""
469 try:
470 return obj[argument]
471 except (AttributeError, TypeError, LookupError):
472 if isinstance(argument, str):
473 try:
474 attr = str(argument)
475 except Exception:
476 pass
477 else:
478 try:
479 return getattr(obj, attr)
480 except AttributeError:
481 pass
482 return self.undefined(obj=obj, name=argument)
484 def getattr(self, obj: t.Any, attribute: str) -> t.Any:
485 """Get an item or attribute of an object but prefer the attribute.
486 Unlike :meth:`getitem` the attribute *must* be a string.
487 """
488 try:
489 return getattr(obj, attribute)
490 except AttributeError:
491 pass
492 try:
493 return obj[attribute]
494 except (TypeError, LookupError, AttributeError):
495 return self.undefined(obj=obj, name=attribute)
497 def _filter_test_common(
498 self,
499 name: t.Union[str, Undefined],
500 value: t.Any,
501 args: t.Optional[t.Sequence[t.Any]],
502 kwargs: t.Optional[t.Mapping[str, t.Any]],
503 context: t.Optional[Context],
504 eval_ctx: t.Optional[EvalContext],
505 is_filter: bool,
506 ) -> t.Any:
507 if is_filter:
508 env_map = self.filters
509 type_name = "filter"
510 else:
511 env_map = self.tests
512 type_name = "test"
514 func = env_map.get(name) # type: ignore
516 if func is None:
517 msg = f"No {type_name} named {name!r}."
519 if isinstance(name, Undefined):
520 try:
521 name._fail_with_undefined_error()
522 except Exception as e:
523 msg = f"{msg} ({e}; did you forget to quote the callable name?)"
525 raise TemplateRuntimeError(msg)
527 args = [value, *(args if args is not None else ())]
528 kwargs = kwargs if kwargs is not None else {}
529 pass_arg = _PassArg.from_obj(func)
531 if pass_arg is _PassArg.context:
532 if context is None:
533 raise TemplateRuntimeError(
534 f"Attempted to invoke a context {type_name} without context."
535 )
537 args.insert(0, context)
538 elif pass_arg is _PassArg.eval_context:
539 if eval_ctx is None:
540 if context is not None:
541 eval_ctx = context.eval_ctx
542 else:
543 eval_ctx = EvalContext(self)
545 args.insert(0, eval_ctx)
546 elif pass_arg is _PassArg.environment:
547 args.insert(0, self)
549 return func(*args, **kwargs)
551 def call_filter(
552 self,
553 name: str,
554 value: t.Any,
555 args: t.Optional[t.Sequence[t.Any]] = None,
556 kwargs: t.Optional[t.Mapping[str, t.Any]] = None,
557 context: t.Optional[Context] = None,
558 eval_ctx: t.Optional[EvalContext] = None,
559 ) -> t.Any:
560 """Invoke a filter on a value the same way the compiler does.
562 This might return a coroutine if the filter is running from an
563 environment in async mode and the filter supports async
564 execution. It's your responsibility to await this if needed.
566 .. versionadded:: 2.7
567 """
568 return self._filter_test_common(
569 name, value, args, kwargs, context, eval_ctx, True
570 )
572 def call_test(
573 self,
574 name: str,
575 value: t.Any,
576 args: t.Optional[t.Sequence[t.Any]] = None,
577 kwargs: t.Optional[t.Mapping[str, t.Any]] = None,
578 context: t.Optional[Context] = None,
579 eval_ctx: t.Optional[EvalContext] = None,
580 ) -> t.Any:
581 """Invoke a test on a value the same way the compiler does.
583 This might return a coroutine if the test is running from an
584 environment in async mode and the test supports async execution.
585 It's your responsibility to await this if needed.
587 .. versionchanged:: 3.0
588 Tests support ``@pass_context``, etc. decorators. Added
589 the ``context`` and ``eval_ctx`` parameters.
591 .. versionadded:: 2.7
592 """
593 return self._filter_test_common(
594 name, value, args, kwargs, context, eval_ctx, False
595 )
597 @internalcode
598 def parse(
599 self,
600 source: str,
601 name: t.Optional[str] = None,
602 filename: t.Optional[str] = None,
603 ) -> nodes.Template:
604 """Parse the sourcecode and return the abstract syntax tree. This
605 tree of nodes is used by the compiler to convert the template into
606 executable source- or bytecode. This is useful for debugging or to
607 extract information from templates.
609 If you are :ref:`developing Jinja extensions <writing-extensions>`
610 this gives you a good overview of the node tree generated.
611 """
612 try:
613 return self._parse(source, name, filename)
614 except TemplateSyntaxError:
615 self.handle_exception(source=source)
617 def _parse(
618 self, source: str, name: t.Optional[str], filename: t.Optional[str]
619 ) -> nodes.Template:
620 """Internal parsing function used by `parse` and `compile`."""
621 return Parser(self, source, name, filename).parse()
623 def lex(
624 self,
625 source: str,
626 name: t.Optional[str] = None,
627 filename: t.Optional[str] = None,
628 ) -> t.Iterator[t.Tuple[int, str, str]]:
629 """Lex the given sourcecode and return a generator that yields
630 tokens as tuples in the form ``(lineno, token_type, value)``.
631 This can be useful for :ref:`extension development <writing-extensions>`
632 and debugging templates.
634 This does not perform preprocessing. If you want the preprocessing
635 of the extensions to be applied you have to filter source through
636 the :meth:`preprocess` method.
637 """
638 source = str(source)
639 try:
640 return self.lexer.tokeniter(source, name, filename)
641 except TemplateSyntaxError:
642 self.handle_exception(source=source)
644 def preprocess(
645 self,
646 source: str,
647 name: t.Optional[str] = None,
648 filename: t.Optional[str] = None,
649 ) -> str:
650 """Preprocesses the source with all extensions. This is automatically
651 called for all parsing and compiling methods but *not* for :meth:`lex`
652 because there you usually only want the actual source tokenized.
653 """
654 return reduce(
655 lambda s, e: e.preprocess(s, name, filename),
656 self.iter_extensions(),
657 str(source),
658 )
660 def _tokenize(
661 self,
662 source: str,
663 name: t.Optional[str],
664 filename: t.Optional[str] = None,
665 state: t.Optional[str] = None,
666 ) -> TokenStream:
667 """Called by the parser to do the preprocessing and filtering
668 for all the extensions. Returns a :class:`~jinja2.lexer.TokenStream`.
669 """
670 source = self.preprocess(source, name, filename)
671 stream = self.lexer.tokenize(source, name, filename, state)
673 for ext in self.iter_extensions():
674 stream = ext.filter_stream(stream) # type: ignore
676 if not isinstance(stream, TokenStream):
677 stream = TokenStream(stream, name, filename) # type: ignore[unreachable]
679 return stream
681 def _generate(
682 self,
683 source: nodes.Template,
684 name: t.Optional[str],
685 filename: t.Optional[str],
686 defer_init: bool = False,
687 ) -> str:
688 """Internal hook that can be overridden to hook a different generate
689 method in.
691 .. versionadded:: 2.5
692 """
693 return generate( # type: ignore
694 source,
695 self,
696 name,
697 filename,
698 defer_init=defer_init,
699 optimized=self.optimized,
700 )
702 def _compile(self, source: str, filename: str) -> CodeType:
703 """Internal hook that can be overridden to hook a different compile
704 method in.
706 .. versionadded:: 2.5
707 """
708 return compile(source, filename, "exec")
710 @typing.overload
711 def compile( # type: ignore
712 self,
713 source: t.Union[str, nodes.Template],
714 name: t.Optional[str] = None,
715 filename: t.Optional[str] = None,
716 raw: "te.Literal[False]" = False,
717 defer_init: bool = False,
718 ) -> CodeType: ...
720 @typing.overload
721 def compile(
722 self,
723 source: t.Union[str, nodes.Template],
724 name: t.Optional[str] = None,
725 filename: t.Optional[str] = None,
726 raw: "te.Literal[True]" = ...,
727 defer_init: bool = False,
728 ) -> str: ...
730 @internalcode
731 def compile(
732 self,
733 source: t.Union[str, nodes.Template],
734 name: t.Optional[str] = None,
735 filename: t.Optional[str] = None,
736 raw: bool = False,
737 defer_init: bool = False,
738 ) -> t.Union[str, CodeType]:
739 """Compile a node or template source code. The `name` parameter is
740 the load name of the template after it was joined using
741 :meth:`join_path` if necessary, not the filename on the file system.
742 the `filename` parameter is the estimated filename of the template on
743 the file system. If the template came from a database or memory this
744 can be omitted.
746 The return value of this method is a python code object. If the `raw`
747 parameter is `True` the return value will be a string with python
748 code equivalent to the bytecode returned otherwise. This method is
749 mainly used internally.
751 `defer_init` is use internally to aid the module code generator. This
752 causes the generated code to be able to import without the global
753 environment variable to be set.
755 .. versionadded:: 2.4
756 `defer_init` parameter added.
757 """
758 source_hint = None
759 try:
760 if isinstance(source, str):
761 source_hint = source
762 source = self._parse(source, name, filename)
763 source = self._generate(source, name, filename, defer_init=defer_init)
764 if raw:
765 return source
766 if filename is None:
767 filename = "<template>"
768 return self._compile(source, filename)
769 except TemplateSyntaxError:
770 self.handle_exception(source=source_hint)
772 def compile_expression(
773 self, source: str, undefined_to_none: bool = True
774 ) -> "TemplateExpression":
775 """A handy helper method that returns a callable that accepts keyword
776 arguments that appear as variables in the expression. If called it
777 returns the result of the expression.
779 This is useful if applications want to use the same rules as Jinja
780 in template "configuration files" or similar situations.
782 Example usage:
784 >>> env = Environment()
785 >>> expr = env.compile_expression('foo == 42')
786 >>> expr(foo=23)
787 False
788 >>> expr(foo=42)
789 True
791 Per default the return value is converted to `None` if the
792 expression returns an undefined value. This can be changed
793 by setting `undefined_to_none` to `False`.
795 >>> env.compile_expression('var')() is None
796 True
797 >>> env.compile_expression('var', undefined_to_none=False)()
798 Undefined
800 .. versionadded:: 2.1
801 """
802 parser = Parser(self, source, state="variable")
803 try:
804 expr = parser.parse_expression()
805 if not parser.stream.eos:
806 raise TemplateSyntaxError(
807 "chunk after expression", parser.stream.current.lineno, None, None
808 )
809 expr.set_environment(self)
810 except TemplateSyntaxError:
811 self.handle_exception(source=source)
813 body = [nodes.Assign(nodes.Name("result", "store"), expr, lineno=1)]
814 template = self.from_string(nodes.Template(body, lineno=1))
815 return TemplateExpression(template, undefined_to_none)
817 def compile_templates(
818 self,
819 target: t.Union[str, "os.PathLike[str]"],
820 extensions: t.Optional[t.Collection[str]] = None,
821 filter_func: t.Optional[t.Callable[[str], bool]] = None,
822 zip: t.Optional[str] = "deflated",
823 log_function: t.Optional[t.Callable[[str], None]] = None,
824 ignore_errors: bool = True,
825 ) -> None:
826 """Finds all the templates the loader can find, compiles them
827 and stores them in `target`. If `zip` is `None`, instead of in a
828 zipfile, the templates will be stored in a directory.
829 By default a deflate zip algorithm is used. To switch to
830 the stored algorithm, `zip` can be set to ``'stored'``.
832 `extensions` and `filter_func` are passed to :meth:`list_templates`.
833 Each template returned will be compiled to the target folder or
834 zipfile.
836 By default template compilation errors are ignored. In case a
837 log function is provided, errors are logged. If you want template
838 syntax errors to abort the compilation you can set `ignore_errors`
839 to `False` and you will get an exception on syntax errors.
841 .. versionadded:: 2.4
842 """
843 from .loaders import ModuleLoader
845 if log_function is None:
847 def log_function(x: str) -> None:
848 pass
850 assert log_function is not None
851 assert self.loader is not None, "No loader configured."
853 def write_file(filename: str, data: str) -> None:
854 if zip:
855 info = ZipInfo(filename)
856 info.external_attr = 0o755 << 16
857 zip_file.writestr(info, data)
858 else:
859 with open(os.path.join(target, filename), "wb") as f:
860 f.write(data.encode("utf8"))
862 if zip is not None:
863 from zipfile import ZIP_DEFLATED
864 from zipfile import ZIP_STORED
865 from zipfile import ZipFile
866 from zipfile import ZipInfo
868 zip_file = ZipFile(
869 target, "w", dict(deflated=ZIP_DEFLATED, stored=ZIP_STORED)[zip]
870 )
871 log_function(f"Compiling into Zip archive {target!r}")
872 else:
873 if not os.path.isdir(target):
874 os.makedirs(target)
875 log_function(f"Compiling into folder {target!r}")
877 try:
878 for name in self.list_templates(extensions, filter_func):
879 source, filename, _ = self.loader.get_source(self, name)
880 try:
881 code = self.compile(source, name, filename, True, True)
882 except TemplateSyntaxError as e:
883 if not ignore_errors:
884 raise
885 log_function(f'Could not compile "{name}": {e}')
886 continue
888 filename = ModuleLoader.get_module_filename(name)
890 write_file(filename, code)
891 log_function(f'Compiled "{name}" as {filename}')
892 finally:
893 if zip:
894 zip_file.close()
896 log_function("Finished compiling templates")
898 def list_templates(
899 self,
900 extensions: t.Optional[t.Collection[str]] = None,
901 filter_func: t.Optional[t.Callable[[str], bool]] = None,
902 ) -> t.List[str]:
903 """Returns a list of templates for this environment. This requires
904 that the loader supports the loader's
905 :meth:`~BaseLoader.list_templates` method.
907 If there are other files in the template folder besides the
908 actual templates, the returned list can be filtered. There are two
909 ways: either `extensions` is set to a list of file extensions for
910 templates, or a `filter_func` can be provided which is a callable that
911 is passed a template name and should return `True` if it should end up
912 in the result list.
914 If the loader does not support that, a :exc:`TypeError` is raised.
916 .. versionadded:: 2.4
917 """
918 assert self.loader is not None, "No loader configured."
919 names = self.loader.list_templates()
921 if extensions is not None:
922 if filter_func is not None:
923 raise TypeError(
924 "either extensions or filter_func can be passed, but not both"
925 )
927 def filter_func(x: str) -> bool:
928 return "." in x and x.rsplit(".", 1)[1] in extensions
930 if filter_func is not None:
931 names = [name for name in names if filter_func(name)]
933 return names
935 def handle_exception(self, source: t.Optional[str] = None) -> "te.NoReturn":
936 """Exception handling helper. This is used internally to either raise
937 rewritten exceptions or return a rendered traceback for the template.
938 """
939 from .debug import rewrite_traceback_stack
941 raise rewrite_traceback_stack(source=source)
943 def join_path(self, template: str, parent: str) -> str:
944 """Join a template with the parent. By default all the lookups are
945 relative to the loader root so this method returns the `template`
946 parameter unchanged, but if the paths should be relative to the
947 parent template, this function can be used to calculate the real
948 template name.
950 Subclasses may override this method and implement template path
951 joining here.
952 """
953 return template
955 @internalcode
956 def _load_template(
957 self, name: str, globals: t.Optional[t.MutableMapping[str, t.Any]]
958 ) -> "Template":
959 if self.loader is None:
960 raise TypeError("no loader for this environment specified")
961 cache_key = (weakref.ref(self.loader), name)
962 if self.cache is not None:
963 template = self.cache.get(cache_key)
964 if template is not None and (
965 not self.auto_reload or template.is_up_to_date
966 ):
967 # template.globals is a ChainMap, modifying it will only
968 # affect the template, not the environment globals.
969 if globals:
970 template.globals.update(globals)
972 return template
974 template = self.loader.load(self, name, self.make_globals(globals))
976 if self.cache is not None:
977 self.cache[cache_key] = template
978 return template
980 @internalcode
981 def get_template(
982 self,
983 name: t.Union[str, "Template"],
984 parent: t.Optional[str] = None,
985 globals: t.Optional[t.MutableMapping[str, t.Any]] = None,
986 ) -> "Template":
987 """Load a template by name with :attr:`loader` and return a
988 :class:`Template`. If the template does not exist a
989 :exc:`TemplateNotFound` exception is raised.
991 :param name: Name of the template to load. When loading
992 templates from the filesystem, "/" is used as the path
993 separator, even on Windows.
994 :param parent: The name of the parent template importing this
995 template. :meth:`join_path` can be used to implement name
996 transformations with this.
997 :param globals: Extend the environment :attr:`globals` with
998 these extra variables available for all renders of this
999 template. If the template has already been loaded and
1000 cached, its globals are updated with any new items.
1002 .. versionchanged:: 3.0
1003 If a template is loaded from cache, ``globals`` will update
1004 the template's globals instead of ignoring the new values.
1006 .. versionchanged:: 2.4
1007 If ``name`` is a :class:`Template` object it is returned
1008 unchanged.
1009 """
1010 if isinstance(name, Template):
1011 return name
1012 if parent is not None:
1013 name = self.join_path(name, parent)
1015 return self._load_template(name, globals)
1017 @internalcode
1018 def select_template(
1019 self,
1020 names: t.Iterable[t.Union[str, "Template"]],
1021 parent: t.Optional[str] = None,
1022 globals: t.Optional[t.MutableMapping[str, t.Any]] = None,
1023 ) -> "Template":
1024 """Like :meth:`get_template`, but tries loading multiple names.
1025 If none of the names can be loaded a :exc:`TemplatesNotFound`
1026 exception is raised.
1028 :param names: List of template names to try loading in order.
1029 :param parent: The name of the parent template importing this
1030 template. :meth:`join_path` can be used to implement name
1031 transformations with this.
1032 :param globals: Extend the environment :attr:`globals` with
1033 these extra variables available for all renders of this
1034 template. If the template has already been loaded and
1035 cached, its globals are updated with any new items.
1037 .. versionchanged:: 3.0
1038 If a template is loaded from cache, ``globals`` will update
1039 the template's globals instead of ignoring the new values.
1041 .. versionchanged:: 2.11
1042 If ``names`` is :class:`Undefined`, an :exc:`UndefinedError`
1043 is raised instead. If no templates were found and ``names``
1044 contains :class:`Undefined`, the message is more helpful.
1046 .. versionchanged:: 2.4
1047 If ``names`` contains a :class:`Template` object it is
1048 returned unchanged.
1050 .. versionadded:: 2.3
1051 """
1052 if isinstance(names, Undefined):
1053 names._fail_with_undefined_error()
1055 if not names:
1056 raise TemplatesNotFound(
1057 message="Tried to select from an empty list of templates."
1058 )
1060 for name in names:
1061 if isinstance(name, Template):
1062 return name
1063 if parent is not None:
1064 name = self.join_path(name, parent)
1065 try:
1066 return self._load_template(name, globals)
1067 except (TemplateNotFound, UndefinedError):
1068 pass
1069 raise TemplatesNotFound(names) # type: ignore
1071 @internalcode
1072 def get_or_select_template(
1073 self,
1074 template_name_or_list: t.Union[
1075 str, "Template", t.List[t.Union[str, "Template"]]
1076 ],
1077 parent: t.Optional[str] = None,
1078 globals: t.Optional[t.MutableMapping[str, t.Any]] = None,
1079 ) -> "Template":
1080 """Use :meth:`select_template` if an iterable of template names
1081 is given, or :meth:`get_template` if one name is given.
1083 .. versionadded:: 2.3
1084 """
1085 if isinstance(template_name_or_list, (str, Undefined)):
1086 return self.get_template(template_name_or_list, parent, globals)
1087 elif isinstance(template_name_or_list, Template):
1088 return template_name_or_list
1089 return self.select_template(template_name_or_list, parent, globals)
1091 def from_string(
1092 self,
1093 source: t.Union[str, nodes.Template],
1094 globals: t.Optional[t.MutableMapping[str, t.Any]] = None,
1095 template_class: t.Optional[t.Type["Template"]] = None,
1096 ) -> "Template":
1097 """Load a template from a source string without using
1098 :attr:`loader`.
1100 :param source: Jinja source to compile into a template.
1101 :param globals: Extend the environment :attr:`globals` with
1102 these extra variables available for all renders of this
1103 template. If the template has already been loaded and
1104 cached, its globals are updated with any new items.
1105 :param template_class: Return an instance of this
1106 :class:`Template` class.
1107 """
1108 gs = self.make_globals(globals)
1109 cls = template_class or self.template_class
1110 return cls.from_code(self, self.compile(source), gs, None)
1112 def make_globals(
1113 self, d: t.Optional[t.MutableMapping[str, t.Any]]
1114 ) -> t.MutableMapping[str, t.Any]:
1115 """Make the globals map for a template. Any given template
1116 globals overlay the environment :attr:`globals`.
1118 Returns a :class:`collections.ChainMap`. This allows any changes
1119 to a template's globals to only affect that template, while
1120 changes to the environment's globals are still reflected.
1121 However, avoid modifying any globals after a template is loaded.
1123 :param d: Dict of template-specific globals.
1125 .. versionchanged:: 3.0
1126 Use :class:`collections.ChainMap` to always prevent mutating
1127 environment globals.
1128 """
1129 if d is None:
1130 d = {}
1132 return ChainMap(d, self.globals)
1135class Template:
1136 """A compiled template that can be rendered.
1138 Use the methods on :class:`Environment` to create or load templates.
1139 The environment is used to configure how templates are compiled and
1140 behave.
1142 It is also possible to create a template object directly. This is
1143 not usually recommended. The constructor takes most of the same
1144 arguments as :class:`Environment`. All templates created with the
1145 same environment arguments share the same ephemeral ``Environment``
1146 instance behind the scenes.
1148 A template object should be considered immutable. Modifications on
1149 the object are not supported.
1150 """
1152 #: Type of environment to create when creating a template directly
1153 #: rather than through an existing environment.
1154 environment_class: t.Type[Environment] = Environment
1156 environment: Environment
1157 globals: t.MutableMapping[str, t.Any]
1158 name: t.Optional[str]
1159 filename: t.Optional[str]
1160 blocks: t.Dict[str, t.Callable[[Context], t.Iterator[str]]]
1161 root_render_func: t.Callable[[Context], t.Iterator[str]]
1162 _module: t.Optional["TemplateModule"]
1163 _debug_info: str
1164 _uptodate: t.Optional[t.Callable[[], bool]]
1166 def __new__(
1167 cls,
1168 source: t.Union[str, nodes.Template],
1169 block_start_string: str = BLOCK_START_STRING,
1170 block_end_string: str = BLOCK_END_STRING,
1171 variable_start_string: str = VARIABLE_START_STRING,
1172 variable_end_string: str = VARIABLE_END_STRING,
1173 comment_start_string: str = COMMENT_START_STRING,
1174 comment_end_string: str = COMMENT_END_STRING,
1175 line_statement_prefix: t.Optional[str] = LINE_STATEMENT_PREFIX,
1176 line_comment_prefix: t.Optional[str] = LINE_COMMENT_PREFIX,
1177 trim_blocks: bool = TRIM_BLOCKS,
1178 lstrip_blocks: bool = LSTRIP_BLOCKS,
1179 newline_sequence: "te.Literal['\\n', '\\r\\n', '\\r']" = NEWLINE_SEQUENCE,
1180 keep_trailing_newline: bool = KEEP_TRAILING_NEWLINE,
1181 extensions: t.Sequence[t.Union[str, t.Type["Extension"]]] = (),
1182 optimized: bool = True,
1183 undefined: t.Type[Undefined] = Undefined,
1184 finalize: t.Optional[t.Callable[..., t.Any]] = None,
1185 autoescape: t.Union[bool, t.Callable[[t.Optional[str]], bool]] = False,
1186 enable_async: bool = False,
1187 ) -> t.Any: # it returns a `Template`, but this breaks the sphinx build...
1188 env = get_spontaneous_environment(
1189 cls.environment_class, # type: ignore
1190 block_start_string,
1191 block_end_string,
1192 variable_start_string,
1193 variable_end_string,
1194 comment_start_string,
1195 comment_end_string,
1196 line_statement_prefix,
1197 line_comment_prefix,
1198 trim_blocks,
1199 lstrip_blocks,
1200 newline_sequence,
1201 keep_trailing_newline,
1202 frozenset(extensions),
1203 optimized,
1204 undefined, # type: ignore
1205 finalize,
1206 autoescape,
1207 None,
1208 0,
1209 False,
1210 None,
1211 enable_async,
1212 )
1213 return env.from_string(source, template_class=cls)
1215 @classmethod
1216 def from_code(
1217 cls,
1218 environment: Environment,
1219 code: CodeType,
1220 globals: t.MutableMapping[str, t.Any],
1221 uptodate: t.Optional[t.Callable[[], bool]] = None,
1222 ) -> "Template":
1223 """Creates a template object from compiled code and the globals. This
1224 is used by the loaders and environment to create a template object.
1225 """
1226 namespace = {"environment": environment, "__file__": code.co_filename}
1227 exec(code, namespace)
1228 rv = cls._from_namespace(environment, namespace, globals)
1229 rv._uptodate = uptodate
1230 return rv
1232 @classmethod
1233 def from_module_dict(
1234 cls,
1235 environment: Environment,
1236 module_dict: t.MutableMapping[str, t.Any],
1237 globals: t.MutableMapping[str, t.Any],
1238 ) -> "Template":
1239 """Creates a template object from a module. This is used by the
1240 module loader to create a template object.
1242 .. versionadded:: 2.4
1243 """
1244 return cls._from_namespace(environment, module_dict, globals)
1246 @classmethod
1247 def _from_namespace(
1248 cls,
1249 environment: Environment,
1250 namespace: t.MutableMapping[str, t.Any],
1251 globals: t.MutableMapping[str, t.Any],
1252 ) -> "Template":
1253 t: Template = object.__new__(cls)
1254 t.environment = environment
1255 t.globals = globals
1256 t.name = namespace["name"]
1257 t.filename = namespace["__file__"]
1258 t.blocks = namespace["blocks"]
1260 # render function and module
1261 t.root_render_func = namespace["root"]
1262 t._module = None
1264 # debug and loader helpers
1265 t._debug_info = namespace["debug_info"]
1266 t._uptodate = None
1268 # store the reference
1269 namespace["environment"] = environment
1270 namespace["__jinja_template__"] = t
1272 return t
1274 def render(self, *args: t.Any, **kwargs: t.Any) -> str:
1275 """This method accepts the same arguments as the `dict` constructor:
1276 A dict, a dict subclass or some keyword arguments. If no arguments
1277 are given the context will be empty. These two calls do the same::
1279 template.render(knights='that say nih')
1280 template.render({'knights': 'that say nih'})
1282 This will return the rendered template as a string.
1283 """
1284 if self.environment.is_async:
1285 import asyncio
1287 return asyncio.run(self.render_async(*args, **kwargs))
1289 ctx = self.new_context(dict(*args, **kwargs))
1291 try:
1292 return self.environment.concat(self.root_render_func(ctx)) # type: ignore
1293 except Exception:
1294 self.environment.handle_exception()
1296 async def render_async(self, *args: t.Any, **kwargs: t.Any) -> str:
1297 """This works similar to :meth:`render` but returns a coroutine
1298 that when awaited returns the entire rendered template string. This
1299 requires the async feature to be enabled.
1301 Example usage::
1303 await template.render_async(knights='that say nih; asynchronously')
1304 """
1305 if not self.environment.is_async:
1306 raise RuntimeError(
1307 "The environment was not created with async mode enabled."
1308 )
1310 ctx = self.new_context(dict(*args, **kwargs))
1312 try:
1313 return self.environment.concat( # type: ignore
1314 [n async for n in self.root_render_func(ctx)] # type: ignore
1315 )
1316 except Exception:
1317 return self.environment.handle_exception()
1319 def stream(self, *args: t.Any, **kwargs: t.Any) -> "TemplateStream":
1320 """Works exactly like :meth:`generate` but returns a
1321 :class:`TemplateStream`.
1322 """
1323 return TemplateStream(self.generate(*args, **kwargs))
1325 def generate(self, *args: t.Any, **kwargs: t.Any) -> t.Iterator[str]:
1326 """For very large templates it can be useful to not render the whole
1327 template at once but evaluate each statement after another and yield
1328 piece for piece. This method basically does exactly that and returns
1329 a generator that yields one item after another as strings.
1331 It accepts the same arguments as :meth:`render`.
1332 """
1333 if self.environment.is_async:
1334 import asyncio
1336 async def to_list() -> t.List[str]:
1337 return [x async for x in self.generate_async(*args, **kwargs)]
1339 yield from asyncio.run(to_list())
1340 return
1342 ctx = self.new_context(dict(*args, **kwargs))
1344 try:
1345 yield from self.root_render_func(ctx)
1346 except Exception:
1347 yield self.environment.handle_exception()
1349 async def generate_async(
1350 self, *args: t.Any, **kwargs: t.Any
1351 ) -> t.AsyncGenerator[str, object]:
1352 """An async version of :meth:`generate`. Works very similarly but
1353 returns an async iterator instead.
1354 """
1355 if not self.environment.is_async:
1356 raise RuntimeError(
1357 "The environment was not created with async mode enabled."
1358 )
1360 ctx = self.new_context(dict(*args, **kwargs))
1362 try:
1363 agen = self.root_render_func(ctx)
1364 try:
1365 async for event in agen: # type: ignore
1366 yield event
1367 finally:
1368 # we can't use async with aclosing(...) because that's only
1369 # in 3.10+
1370 await agen.aclose() # type: ignore
1371 except Exception:
1372 yield self.environment.handle_exception()
1374 def new_context(
1375 self,
1376 vars: t.Optional[t.Dict[str, t.Any]] = None,
1377 shared: bool = False,
1378 locals: t.Optional[t.Mapping[str, t.Any]] = None,
1379 ) -> Context:
1380 """Create a new :class:`Context` for this template. The vars
1381 provided will be passed to the template. Per default the globals
1382 are added to the context. If shared is set to `True` the data
1383 is passed as is to the context without adding the globals.
1385 `locals` can be a dict of local variables for internal usage.
1386 """
1387 return new_context(
1388 self.environment, self.name, self.blocks, vars, shared, self.globals, locals
1389 )
1391 def make_module(
1392 self,
1393 vars: t.Optional[t.Dict[str, t.Any]] = None,
1394 shared: bool = False,
1395 locals: t.Optional[t.Mapping[str, t.Any]] = None,
1396 ) -> "TemplateModule":
1397 """This method works like the :attr:`module` attribute when called
1398 without arguments but it will evaluate the template on every call
1399 rather than caching it. It's also possible to provide
1400 a dict which is then used as context. The arguments are the same
1401 as for the :meth:`new_context` method.
1402 """
1403 ctx = self.new_context(vars, shared, locals)
1404 return TemplateModule(self, ctx)
1406 async def make_module_async(
1407 self,
1408 vars: t.Optional[t.Dict[str, t.Any]] = None,
1409 shared: bool = False,
1410 locals: t.Optional[t.Mapping[str, t.Any]] = None,
1411 ) -> "TemplateModule":
1412 """As template module creation can invoke template code for
1413 asynchronous executions this method must be used instead of the
1414 normal :meth:`make_module` one. Likewise the module attribute
1415 becomes unavailable in async mode.
1416 """
1417 ctx = self.new_context(vars, shared, locals)
1418 return TemplateModule(
1419 self,
1420 ctx,
1421 [x async for x in self.root_render_func(ctx)], # type: ignore
1422 )
1424 @internalcode
1425 def _get_default_module(self, ctx: t.Optional[Context] = None) -> "TemplateModule":
1426 """If a context is passed in, this means that the template was
1427 imported. Imported templates have access to the current
1428 template's globals by default, but they can only be accessed via
1429 the context during runtime.
1431 If there are new globals, we need to create a new module because
1432 the cached module is already rendered and will not have access
1433 to globals from the current context. This new module is not
1434 cached because the template can be imported elsewhere, and it
1435 should have access to only the current template's globals.
1436 """
1437 if self.environment.is_async:
1438 raise RuntimeError("Module is not available in async mode.")
1440 if ctx is not None:
1441 keys = ctx.globals_keys - self.globals.keys()
1443 if keys:
1444 return self.make_module({k: ctx.parent[k] for k in keys})
1446 if self._module is None:
1447 self._module = self.make_module()
1449 return self._module
1451 async def _get_default_module_async(
1452 self, ctx: t.Optional[Context] = None
1453 ) -> "TemplateModule":
1454 if ctx is not None:
1455 keys = ctx.globals_keys - self.globals.keys()
1457 if keys:
1458 return await self.make_module_async({k: ctx.parent[k] for k in keys})
1460 if self._module is None:
1461 self._module = await self.make_module_async()
1463 return self._module
1465 @property
1466 def module(self) -> "TemplateModule":
1467 """The template as module. This is used for imports in the
1468 template runtime but is also useful if one wants to access
1469 exported template variables from the Python layer:
1471 >>> t = Template('{% macro foo() %}42{% endmacro %}23')
1472 >>> str(t.module)
1473 '23'
1474 >>> t.module.foo() == u'42'
1475 True
1477 This attribute is not available if async mode is enabled.
1478 """
1479 return self._get_default_module()
1481 def get_corresponding_lineno(self, lineno: int) -> int:
1482 """Return the source line number of a line number in the
1483 generated bytecode as they are not in sync.
1484 """
1485 for template_line, code_line in reversed(self.debug_info):
1486 if code_line <= lineno:
1487 return template_line
1488 return 1
1490 @property
1491 def is_up_to_date(self) -> bool:
1492 """If this variable is `False` there is a newer version available."""
1493 if self._uptodate is None:
1494 return True
1495 return self._uptodate()
1497 @property
1498 def debug_info(self) -> t.List[t.Tuple[int, int]]:
1499 """The debug info mapping."""
1500 if self._debug_info:
1501 return [
1502 tuple(map(int, x.split("="))) # type: ignore
1503 for x in self._debug_info.split("&")
1504 ]
1506 return []
1508 def __repr__(self) -> str:
1509 if self.name is None:
1510 name = f"memory:{id(self):x}"
1511 else:
1512 name = repr(self.name)
1513 return f"<{type(self).__name__} {name}>"
1516class TemplateModule:
1517 """Represents an imported template. All the exported names of the
1518 template are available as attributes on this object. Additionally
1519 converting it into a string renders the contents.
1520 """
1522 def __init__(
1523 self,
1524 template: Template,
1525 context: Context,
1526 body_stream: t.Optional[t.Iterable[str]] = None,
1527 ) -> None:
1528 if body_stream is None:
1529 if context.environment.is_async:
1530 raise RuntimeError(
1531 "Async mode requires a body stream to be passed to"
1532 " a template module. Use the async methods of the"
1533 " API you are using."
1534 )
1536 body_stream = list(template.root_render_func(context))
1538 self._body_stream = body_stream
1539 self.__dict__.update(context.get_exported())
1540 self.__name__ = template.name
1542 def __html__(self) -> Markup:
1543 return Markup(concat(self._body_stream))
1545 def __str__(self) -> str:
1546 return concat(self._body_stream)
1548 def __repr__(self) -> str:
1549 if self.__name__ is None:
1550 name = f"memory:{id(self):x}"
1551 else:
1552 name = repr(self.__name__)
1553 return f"<{type(self).__name__} {name}>"
1556class TemplateExpression:
1557 """The :meth:`jinja2.Environment.compile_expression` method returns an
1558 instance of this object. It encapsulates the expression-like access
1559 to the template with an expression it wraps.
1560 """
1562 def __init__(self, template: Template, undefined_to_none: bool) -> None:
1563 self._template = template
1564 self._undefined_to_none = undefined_to_none
1566 def __call__(self, *args: t.Any, **kwargs: t.Any) -> t.Optional[t.Any]:
1567 context = self._template.new_context(dict(*args, **kwargs))
1568 consume(self._template.root_render_func(context))
1569 rv = context.vars["result"]
1570 if self._undefined_to_none and isinstance(rv, Undefined):
1571 rv = None
1572 return rv
1575class TemplateStream:
1576 """A template stream works pretty much like an ordinary python generator
1577 but it can buffer multiple items to reduce the number of total iterations.
1578 Per default the output is unbuffered which means that for every unbuffered
1579 instruction in the template one string is yielded.
1581 If buffering is enabled with a buffer size of 5, five items are combined
1582 into a new string. This is mainly useful if you are streaming
1583 big templates to a client via WSGI which flushes after each iteration.
1584 """
1586 def __init__(self, gen: t.Iterator[str]) -> None:
1587 self._gen = gen
1588 self.disable_buffering()
1590 def dump(
1591 self,
1592 fp: t.Union[str, t.IO[bytes]],
1593 encoding: t.Optional[str] = None,
1594 errors: t.Optional[str] = "strict",
1595 ) -> None:
1596 """Dump the complete stream into a file or file-like object.
1597 Per default strings are written, if you want to encode
1598 before writing specify an `encoding`.
1600 Example usage::
1602 Template('Hello {{ name }}!').stream(name='foo').dump('hello.html')
1603 """
1604 close = False
1606 if isinstance(fp, str):
1607 if encoding is None:
1608 encoding = "utf-8"
1610 real_fp: t.IO[bytes] = open(fp, "wb")
1611 close = True
1612 else:
1613 real_fp = fp
1615 try:
1616 if encoding is not None:
1617 iterable = (x.encode(encoding, errors) for x in self) # type: ignore
1618 else:
1619 iterable = self # type: ignore
1621 if hasattr(real_fp, "writelines"):
1622 real_fp.writelines(iterable)
1623 else:
1624 for item in iterable:
1625 real_fp.write(item)
1626 finally:
1627 if close:
1628 real_fp.close()
1630 def disable_buffering(self) -> None:
1631 """Disable the output buffering."""
1632 self._next = partial(next, self._gen)
1633 self.buffered = False
1635 def _buffered_generator(self, size: int) -> t.Iterator[str]:
1636 buf: t.List[str] = []
1637 c_size = 0
1638 push = buf.append
1640 while True:
1641 try:
1642 while c_size < size:
1643 c = next(self._gen)
1644 push(c)
1645 if c:
1646 c_size += 1
1647 except StopIteration:
1648 if not c_size:
1649 return
1650 yield concat(buf)
1651 del buf[:]
1652 c_size = 0
1654 def enable_buffering(self, size: int = 5) -> None:
1655 """Enable buffering. Buffer `size` items before yielding them."""
1656 if size <= 1:
1657 raise ValueError("buffer size too small")
1659 self.buffered = True
1660 self._next = partial(next, self._buffered_generator(size))
1662 def __iter__(self) -> "TemplateStream":
1663 return self
1665 def __next__(self) -> str:
1666 return self._next() # type: ignore
1669# hook in default template class. if anyone reads this comment: ignore that
1670# it's possible to use custom templates ;-)
1671Environment.template_class = Template