JezK
Edit File: environment.py
"""Classes for managing templates and their runtime and compile time options. """ import os import typing import typing as t import weakref from collections import ChainMap from functools import lru_cache from functools import partial from functools import reduce from types import CodeType from markupsafe import Markup from . import nodes from .compiler import CodeGenerator from .compiler import generate from .defaults import BLOCK_END_STRING from .defaults import BLOCK_START_STRING from .defaults import COMMENT_END_STRING from .defaults import COMMENT_START_STRING from .defaults import DEFAULT_FILTERS from .defaults import DEFAULT_NAMESPACE from .defaults import DEFAULT_POLICIES from .defaults import DEFAULT_TESTS from .defaults import KEEP_TRAILING_NEWLINE from .defaults import LINE_COMMENT_PREFIX from .defaults import LINE_STATEMENT_PREFIX from .defaults import LSTRIP_BLOCKS from .defaults import NEWLINE_SEQUENCE from .defaults import TRIM_BLOCKS from .defaults import VARIABLE_END_STRING from .defaults import VARIABLE_START_STRING from .exceptions import TemplateNotFound from .exceptions import TemplateRuntimeError from .exceptions import TemplatesNotFound from .exceptions import TemplateSyntaxError from .exceptions import UndefinedError from .lexer import get_lexer from .lexer import Lexer from .lexer import TokenStream from .nodes import EvalContext from .parser import Parser from .runtime import Context from .runtime import new_context from .runtime import Undefined from .utils import _PassArg from .utils import concat from .utils import consume from .utils import import_string from .utils import internalcode from .utils import LRUCache from .utils import missing if t.TYPE_CHECKING: import typing_extensions as te from .bccache import BytecodeCache from .ext import Extension from .loaders import BaseLoader _env_bound = t.TypeVar("_env_bound", bound="Environment") # for direct template usage we have up to ten living environments @lru_cache(maxsize=10) def get_spontaneous_environment(cls: t.Type[_env_bound], *args: t.Any) -> _env_bound: """Return a new spontaneous environment. A spontaneous environment is used for templates created directly rather than through an existing environment. :param cls: Environment class to create. :param args: Positional arguments passed to environment. """ env = cls(*args) env.shared = True return env def create_cache( size: int, ) -> t.Optional[t.MutableMapping[t.Tuple[weakref.ref, str], "Template"]]: """Return the cache class for the given size.""" if size == 0: return None if size < 0: return {} return LRUCache(size) # type: ignore def copy_cache( cache: t.Optional[t.MutableMapping], ) -> t.Optional[t.MutableMapping[t.Tuple[weakref.ref, str], "Template"]]: """Create an empty copy of the given cache.""" if cache is None: return None if type(cache) is dict: return {} return LRUCache(cache.capacity) # type: ignore def load_extensions( environment: "Environment", extensions: t.Sequence[t.Union[str, t.Type["Extension"]]], ) -> t.Dict[str, "Extension"]: """Load the extensions from the list and bind it to the environment. Returns a dict of instantiated extensions. """ result = {} for extension in extensions: if isinstance(extension, str): extension = t.cast(t.Type["Extension"], import_string(extension)) result[extension.identifier] = extension(environment) return result def _environment_config_check(environment: "Environment") -> "Environment": """Perform a sanity check on the environment.""" assert issubclass( environment.undefined, Undefined ), "'undefined' must be a subclass of 'jinja2.Undefined'." assert ( environment.block_start_string != environment.variable_start_string != environment.comment_start_string ), "block, variable and comment start strings must be different." assert environment.newline_sequence in { "\r", "\r\n", "\n", }, "'newline_sequence' must be one of '\\n', '\\r\\n', or '\\r'." return environment class Environment: r"""The core component of Jinja is the `Environment`. It contains important shared variables like configuration, filters, tests, globals and others. Instances of this class may be modified if they are not shared and if no template was loaded so far. Modifications on environments after the first template was loaded will lead to surprising effects and undefined behavior. Here are the possible initialization parameters: `block_start_string` The string marking the beginning of a block. Defaults to ``'{%'``. `block_end_string` The string marking the end of a block. Defaults to ``'%}'``. `variable_start_string` The string marking the beginning of a print statement. Defaults to ``'{{'``. `variable_end_string` The string marking the end of a print statement. Defaults to ``'}}'``. `comment_start_string` The string marking the beginning of a comment. Defaults to ``'{#'``. `comment_end_string` The string marking the end of a comment. Defaults to ``'#}'``. `line_statement_prefix` If given and a string, this will be used as prefix for line based statements. See also :ref:`line-statements`. `line_comment_prefix` If given and a string, this will be used as prefix for line based comments. See also :ref:`line-statements`. .. versionadded:: 2.2 `trim_blocks` If this is set to ``True`` the first newline after a block is removed (block, not variable tag!). Defaults to `False`. `lstrip_blocks` If this is set to ``True`` leading spaces and tabs are stripped from the start of a line to a block. Defaults to `False`. `newline_sequence` The sequence that starts a newline. Must be one of ``'\r'``, ``'\n'`` or ``'\r\n'``. The default is ``'\n'`` which is a useful default for Linux and OS X systems as well as web applications. `keep_trailing_newline` Preserve the trailing newline when rendering templates. The default is ``False``, which causes a single newline, if present, to be stripped from the end of the template. .. versionadded:: 2.7 `extensions` List of Jinja extensions to use. This can either be import paths as strings or extension classes. For more information have a look at :ref:`the extensions documentation <jinja-extensions>`. `optimized` should the optimizer be enabled? Default is ``True``. `undefined` :class:`Undefined` or a subclass of it that is used to represent undefined values in the template. `finalize` A callable that can be used to process the result of a variable expression before it is output. For example one can convert ``None`` implicitly into an empty string here. `autoescape` If set to ``True`` the XML/HTML autoescaping feature is enabled by default. For more details about autoescaping see :class:`~markupsafe.Markup`. As of Jinja 2.4 this can also be a callable that is passed the template name and has to return ``True`` or ``False`` depending on autoescape should be enabled by default. .. versionchanged:: 2.4 `autoescape` can now be a function `loader` The template loader for this environment. `cache_size` The size of the cache. Per default this is ``400`` which means that if more than 400 templates are loaded the loader will clean out the least recently used template. If the cache size is set to ``0`` templates are recompiled all the time, if the cache size is ``-1`` the cache will not be cleaned. .. versionchanged:: 2.8 The cache size was increased to 400 from a low 50. `auto_reload` Some loaders load templates from locations where the template sources may change (ie: file system or database). If ``auto_reload`` is set to ``True`` (default) every time a template is requested the loader checks if the source changed and if yes, it will reload the template. For higher performance it's possible to disable that. `bytecode_cache` If set to a bytecode cache object, this object will provide a cache for the internal Jinja bytecode so that templates don't have to be parsed if they were not changed. See :ref:`bytecode-cache` for more information. `enable_async` If set to true this enables async template execution which allows using async functions and generators. """ #: if this environment is sandboxed. Modifying this variable won't make #: the environment sandboxed though. For a real sandboxed environment #: have a look at jinja2.sandbox. This flag alone controls the code #: generation by the compiler. sandboxed = False #: True if the environment is just an overlay overlayed = False #: the environment this environment is linked to if it is an overlay linked_to: t.Optional["Environment"] = None #: shared environments have this set to `True`. A shared environment #: must not be modified shared = False #: the class that is used for code generation. See #: :class:`~jinja2.compiler.CodeGenerator` for more information. code_generator_class: t.Type["CodeGenerator"] = CodeGenerator concat = "".join #: the context class that is used for templates. See #: :class:`~jinja2.runtime.Context` for more information. context_class: t.Type[Context] = Context template_class: t.Type["Template"] def __init__( self, block_start_string: str = BLOCK_START_STRING, block_end_string: str = BLOCK_END_STRING, variable_start_string: str = VARIABLE_START_STRING, variable_end_string: str = VARIABLE_END_STRING, comment_start_string: str = COMMENT_START_STRING, comment_end_string: str = COMMENT_END_STRING, line_statement_prefix: t.Optional[str] = LINE_STATEMENT_PREFIX, line_comment_prefix: t.Optional[str] = LINE_COMMENT_PREFIX, trim_blocks: bool = TRIM_BLOCKS, lstrip_blocks: bool = LSTRIP_BLOCKS, newline_sequence: "te.Literal['\\n', '\\r\\n', '\\r']" = NEWLINE_SEQUENCE, keep_trailing_newline: bool = KEEP_TRAILING_NEWLINE, extensions: t.Sequence[t.Union[str, t.Type["Extension"]]] = (), optimized: bool = True, undefined: t.Type[Undefined] = Undefined, finalize: t.Optional[t.Callable[..., t.Any]] = None, autoescape: t.Union[bool, t.Callable[[t.Optional[str]], bool]] = False, loader: t.Optional["BaseLoader"] = None, cache_size: int = 400, auto_reload: bool = True, bytecode_cache: t.Optional["BytecodeCache"] = None, enable_async: bool = False, ): # !!Important notice!! # The constructor accepts quite a few arguments that should be # passed by keyword rather than position. However it's important to # not change the order of arguments because it's used at least # internally in those cases: # - spontaneous environments (i18n extension and Template) # - unittests # If parameter changes are required only add parameters at the end # and don't change the arguments (or the defaults!) of the arguments # existing already. # lexer / parser information self.block_start_string = block_start_string self.block_end_string = block_end_string self.variable_start_string = variable_start_string self.variable_end_string = variable_end_string self.comment_start_string = comment_start_string self.comment_end_string = comment_end_string self.line_statement_prefix = line_statement_prefix self.line_comment_prefix = line_comment_prefix self.trim_blocks = trim_blocks self.lstrip_blocks = lstrip_blocks self.newline_sequence = newline_sequence self.keep_trailing_newline = keep_trailing_newline # runtime information self.undefined: t.Type[Undefined] = undefined self.optimized = optimized self.finalize = finalize self.autoescape = autoescape # defaults self.filters = DEFAULT_FILTERS.copy() self.tests = DEFAULT_TESTS.copy() self.globals = DEFAULT_NAMESPACE.copy() # set the loader provided self.loader = loader self.cache = create_cache(cache_size) self.bytecode_cache = bytecode_cache self.auto_reload = auto_reload # configurable policies self.policies = DEFAULT_POLICIES.copy() # load extensions self.extensions = load_extensions(self, extensions) self.is_async = enable_async _environment_config_check(self) def add_extension(self, extension: t.Union[str, t.Type["Extension"]]) -> None: """Adds an extension after the environment was created. .. versionadded:: 2.5 """ self.extensions.update(load_extensions(self, [extension])) def extend(self, **attributes: t.Any) -> None: """Add the items to the instance of the environment if they do not exist yet. This is used by :ref:`extensions <writing-extensions>` to register callbacks and configuration values without breaking inheritance. """ for key, value in attributes.items(): if not hasattr(self, key): setattr(self, key, value) def overlay( self, block_start_string: str = missing, block_end_string: str = missing, variable_start_string: str = missing, variable_end_string: str = missing, comment_start_string: str = missing, comment_end_string: str = missing, line_statement_prefix: t.Optional[str] = missing, line_comment_prefix: t.Optional[str] = missing, trim_blocks: bool = missing, lstrip_blocks: bool = missing, newline_sequence: "te.Literal['\\n', '\\r\\n', '\\r']" = missing, keep_trailing_newline: bool = missing, extensions: t.Sequence[t.Union[str, t.Type["Extension"]]] = missing, optimized: bool = missing, undefined: t.Type[Undefined] = missing, finalize: t.Optional[t.Callable[..., t.Any]] = missing, autoescape: t.Union[bool, t.Callable[[t.Optional[str]], bool]] = missing, loader: t.Optional["BaseLoader"] = missing, cache_size: int = missing, auto_reload: bool = missing, bytecode_cache: t.Optional["BytecodeCache"] = missing, enable_async: bool = False, ) -> "Environment": """Create a new overlay environment that shares all the data with the current environment except for cache and the overridden attributes. Extensions cannot be removed for an overlayed environment. An overlayed environment automatically gets all the extensions of the environment it is linked to plus optional extra extensions. Creating overlays should happen after the initial environment was set up completely. Not all attributes are truly linked, some are just copied over so modifications on the original environment may not shine through. .. versionchanged:: 3.1.2 Added the ``newline_sequence``,, ``keep_trailing_newline``, and ``enable_async`` parameters to match ``__init__``. """ args = dict(locals()) del args["self"], args["cache_size"], args["extensions"], args["enable_async"] rv = object.__new__(self.__class__) rv.__dict__.update(self.__dict__) rv.overlayed = True rv.linked_to = self for key, value in args.items(): if value is not missing: setattr(rv, key, value) if cache_size is not missing: rv.cache = create_cache(cache_size) else: rv.cache = copy_cache(self.cache) rv.extensions = {} for key, value in self.extensions.items(): rv.extensions[key] = value.bind(rv) if extensions is not missing: rv.extensions.update(load_extensions(rv, extensions)) if enable_async is not missing: rv.is_async = enable_async return _environment_config_check(rv) @property def lexer(self) -> Lexer: """The lexer for this environment.""" return get_lexer(self) def iter_extensions(self) -> t.Iterator["Extension"]: """Iterates over the extensions by priority.""" return iter(sorted(self.extensions.values(), key=lambda x: x.priority)) def getitem( self, obj: t.Any, argument: t.Union[str, t.Any] ) -> t.Union[t.Any, Undefined]: """Get an item or attribute of an object but prefer the item.""" try: return obj[argument] except (AttributeError, TypeError, LookupError): if isinstance(argument, str): try: attr = str(argument) except Exception: pass else: try: return getattr(obj, attr) except AttributeError: pass return self.undefined(obj=obj, name=argument) def getattr(self, obj: t.Any, attribute: str) -> t.Any: """Get an item or attribute of an object but prefer the attribute. Unlike :meth:`getitem` the attribute *must* be a string. """ try: return getattr(obj, attribute) except AttributeError: pass try: return obj[attribute] except (TypeError, LookupError, AttributeError): return self.undefined(obj=obj, name=attribute) def _filter_test_common( self, name: t.Union[str, Undefined], value: t.Any, args: t.Optional[t.Sequence[t.Any]], kwargs: t.Optional[t.Mapping[str, t.Any]], context: t.Optional[Context], eval_ctx: t.Optional[EvalContext], is_filter: bool, ) -> t.Any: if is_filter: env_map = self.filters type_name = "filter" else: env_map = self.tests type_name = "test" func = env_map.get(name) # type: ignore if func is None: msg = f"No {type_name} named {name!r}." if isinstance(name, Undefined): try: name._fail_with_undefined_error() except Exception as e: msg = f"{msg} ({e}; did you forget to quote the callable name?)" raise TemplateRuntimeError(msg) args = [value, *(args if args is not None else ())] kwargs = kwargs if kwargs is not None else {} pass_arg = _PassArg.from_obj(func) if pass_arg is _PassArg.context: if context is None: raise TemplateRuntimeError( f"Attempted to invoke a context {type_name} without context." ) args.insert(0, context) elif pass_arg is _PassArg.eval_context: if eval_ctx is None: if context is not None: eval_ctx = context.eval_ctx else: eval_ctx = EvalContext(self) args.insert(0, eval_ctx) elif pass_arg is _PassArg.environment: args.insert(0, self) return func(*args, **kwargs) def call_filter( self, name: str, value: t.Any, args: t.Optional[t.Sequence[t.Any]] = None, kwargs: t.Optional[t.Mapping[str, t.Any]] = None, context: t.Optional[Context] = None, eval_ctx: t.Optional[EvalContext] = None, ) -> t.Any: """Invoke a filter on a value the same way the compiler does. This might return a coroutine if the filter is running from an environment in async mode and the filter supports async execution. It's your responsibility to await this if needed. .. versionadded:: 2.7 """ return self._filter_test_common( name, value, args, kwargs, context, eval_ctx, True ) def call_test( self, name: str, value: t.Any, args: t.Optional[t.Sequence[t.Any]] = None, kwargs: t.Optional[t.Mapping[str, t.Any]] = None, context: t.Optional[Context] = None, eval_ctx: t.Optional[EvalContext] = None, ) -> t.Any: """Invoke a test on a value the same way the compiler does. This might return a coroutine if the test is running from an environment in async mode and the test supports async execution. It's your responsibility to await this if needed. .. versionchanged:: 3.0 Tests support ``@pass_context``, etc. decorators. Added the ``context`` and ``eval_ctx`` parameters. .. versionadded:: 2.7 """ return self._filter_test_common( name, value, args, kwargs, context, eval_ctx, False ) @internalcode def parse( self, source: str, name: t.Optional[str] = None, filename: t.Optional[str] = None, ) -> nodes.Template: """Parse the sourcecode and return the abstract syntax tree. This tree of nodes is used by the compiler to convert the template into executable source- or bytecode. This is useful for debugging or to extract information from templates. If you are :ref:`developing Jinja extensions <writing-extensions>` this gives you a good overview of the node tree generated. """ try: return self._parse(source, name, filename) except TemplateSyntaxError: self.handle_exception(source=source) def _parse( self, source: str, name: t.Optional[str], filename: t.Optional[str] ) -> nodes.Template: """Internal parsing function used by `parse` and `compile`.""" return Parser(self, source, name, filename).parse() def lex( self, source: str, name: t.Optional[str] = None, filename: t.Optional[str] = None, ) -> t.Iterator[t.Tuple[int, str, str]]: """Lex the given sourcecode and return a generator that yields tokens as tuples in the form ``(lineno, token_type, value)``. This can be useful for :ref:`extension development <writing-extensions>` and debugging templates. This does not perform preprocessing. If you want the preprocessing of the extensions to be applied you have to filter source through the :meth:`preprocess` method. """ source = str(source) try: return self.lexer.tokeniter(source, name, filename) except TemplateSyntaxError: self.handle_exception(source=source) def preprocess( self, source: str, name: t.Optional[str] = None, filename: t.Optional[str] = None, ) -> str: """Preprocesses the source with all extensions. This is automatically called for all parsing and compiling methods but *not* for :meth:`lex` because there you usually only want the actual source tokenized. """ return reduce( lambda s, e: e.preprocess(s, name, filename), self.iter_extensions(), str(source), ) def _tokenize( self, source: str, name: t.Optional[str], filename: t.Optional[str] = None, state: t.Optional[str] = None, ) -> TokenStream: """Called by the parser to do the preprocessing and filtering for all the extensions. Returns a :class:`~jinja2.lexer.TokenStream`. """ source = self.preprocess(source, name, filename) stream = self.lexer.tokenize(source, name, filename, state) for ext in self.iter_extensions(): stream = ext.filter_stream(stream) # type: ignore if not isinstance(stream, TokenStream): stream = TokenStream(stream, name, filename) # type: ignore return stream def _generate( self, source: nodes.Template, name: t.Optional[str], filename: t.Optional[str], defer_init: bool = False, ) -> str: """Internal hook that can be overridden to hook a different generate method in. .. versionadded:: 2.5 """ return generate( # type: ignore source, self, name, filename, defer_init=defer_init, optimized=self.optimized, ) def _compile(self, source: str, filename: str) -> CodeType: """Internal hook that can be overridden to hook a different compile method in. .. versionadded:: 2.5 """ return compile(source, filename, "exec") # type: ignore @typing.overload def compile( # type: ignore self, source: t.Union[str, nodes.Template], name: t.Optional[str] = None, filename: t.Optional[str] = None, raw: "te.Literal[False]" = False, defer_init: bool = False, ) -> CodeType: ... @typing.overload def compile( self, source: t.Union[str, nodes.Template], name: t.Optional[str] = None, filename: t.Optional[str] = None, raw: "te.Literal[True]" = ..., defer_init: bool = False, ) -> str: ... @internalcode def compile( self, source: t.Union[str, nodes.Template], name: t.Optional[str] = None, filename: t.Optional[str] = None, raw: bool = False, defer_init: bool = False, ) -> t.Union[str, CodeType]: """Compile a node or template source code. The `name` parameter is the load name of the template after it was joined using :meth:`join_path` if necessary, not the filename on the file system. the `filename` parameter is the estimated filename of the template on the file system. If the template came from a database or memory this can be omitted. The return value of this method is a python code object. If the `raw` parameter is `True` the return value will be a string with python code equivalent to the bytecode returned otherwise. This method is mainly used internally. `defer_init` is use internally to aid the module code generator. This causes the generated code to be able to import without the global environment variable to be set. .. versionadded:: 2.4 `defer_init` parameter added. """ source_hint = None try: if isinstance(source, str): source_hint = source source = self._parse(source, name, filename) source = self._generate(source, name, filename, defer_init=defer_init) if raw: return source if filename is None: filename = "<template>" return self._compile(source, filename) except TemplateSyntaxError: self.handle_exception(source=source_hint) def compile_expression( self, source: str, undefined_to_none: bool = True ) -> "TemplateExpression": """A handy helper method that returns a callable that accepts keyword arguments that appear as variables in the expression. If called it returns the result of the expression. This is useful if applications want to use the same rules as Jinja in template "configuration files" or similar situations. Example usage: >>> env = Environment() >>> expr = env.compile_expression('foo == 42') >>> expr(foo=23) False >>> expr(foo=42) True Per default the return value is converted to `None` if the expression returns an undefined value. This can be changed by setting `undefined_to_none` to `False`. >>> env.compile_expression('var')() is None True >>> env.compile_expression('var', undefined_to_none=False)() Undefined .. versionadded:: 2.1 """ parser = Parser(self, source, state="variable") try: expr = parser.parse_expression() if not parser.stream.eos: raise TemplateSyntaxError( "chunk after expression", parser.stream.current.lineno, None, None ) expr.set_environment(self) except TemplateSyntaxError: self.handle_exception(source=source) body = [nodes.Assign(nodes.Name("result", "store"), expr, lineno=1)] template = self.from_string(nodes.Template(body, lineno=1)) return TemplateExpression(template, undefined_to_none) def compile_templates( self, target: t.Union[str, os.PathLike], extensions: t.Optional[t.Collection[str]] = None, filter_func: t.Optional[t.Callable[[str], bool]] = None, zip: t.Optional[str] = "deflated", log_function: t.Optional[t.Callable[[str], None]] = None, ignore_errors: bool = True, ) -> None: """Finds all the templates the loader can find, compiles them and stores them in `target`. If `zip` is `None`, instead of in a zipfile, the templates will be stored in a directory. By default a deflate zip algorithm is used. To switch to the stored algorithm, `zip` can be set to ``'stored'``. `extensions` and `filter_func` are passed to :meth:`list_templates`. Each template returned will be compiled to the target folder or zipfile. By default template compilation errors are ignored. In case a log function is provided, errors are logged. If you want template syntax errors to abort the compilation you can set `ignore_errors` to `False` and you will get an exception on syntax errors. .. versionadded:: 2.4 """ from .loaders import ModuleLoader if log_function is None: def log_function(x: str) -> None: pass assert log_function is not None assert self.loader is not None, "No loader configured." def write_file(filename: str, data: str) -> None: if zip: info = ZipInfo(filename) info.external_attr = 0o755 << 16 zip_file.writestr(info, data) else: with open(os.path.join(target, filename), "wb") as f: f.write(data.encode("utf8")) if zip is not None: from zipfile import ZipFile, ZipInfo, ZIP_DEFLATED, ZIP_STORED zip_file = ZipFile( target, "w", dict(deflated=ZIP_DEFLATED, stored=ZIP_STORED)[zip] ) log_function(f"Compiling into Zip archive {target!r}") else: if not os.path.isdir(target): os.makedirs(target) log_function(f"Compiling into folder {target!r}") try: for name in self.list_templates(extensions, filter_func): source, filename, _ = self.loader.get_source(self, name) try: code = self.compile(source, name, filename, True, True) except TemplateSyntaxError as e: if not ignore_errors: raise log_function(f'Could not compile "{name}": {e}') continue filename = ModuleLoader.get_module_filename(name) write_file(filename, code) log_function(f'Compiled "{name}" as {filename}') finally: if zip: zip_file.close() log_function("Finished compiling templates") def list_templates( self, extensions: t.Optional[t.Collection[str]] = None, filter_func: t.Optional[t.Callable[[str], bool]] = None, ) -> t.List[str]: """Returns a list of templates for this environment. This requires that the loader supports the loader's :meth:`~BaseLoader.list_templates` method. If there are other files in the template folder besides the actual templates, the returned list can be filtered. There are two ways: either `extensions` is set to a list of file extensions for templates, or a `filter_func` can be provided which is a callable that is passed a template name and should return `True` if it should end up in the result list. If the loader does not support that, a :exc:`TypeError` is raised. .. versionadded:: 2.4 """ assert self.loader is not None, "No loader configured." names = self.loader.list_templates() if extensions is not None: if filter_func is not None: raise TypeError( "either extensions or filter_func can be passed, but not both" ) def filter_func(x: str) -> bool: return "." in x and x.rsplit(".", 1)[1] in extensions # type: ignore if filter_func is not None: names = [name for name in names if filter_func(name)] return names def handle_exception(self, source: t.Optional[str] = None) -> "te.NoReturn": """Exception handling helper. This is used internally to either raise rewritten exceptions or return a rendered traceback for the template. """ from .debug import rewrite_traceback_stack raise rewrite_traceback_stack(source=source) def join_path(self, template: str, parent: str) -> str: """Join a template with the parent. By default all the lookups are relative to the loader root so this method returns the `template` parameter unchanged, but if the paths should be relative to the parent template, this function can be used to calculate the real template name. Subclasses may override this method and implement template path joining here. """ return template @internalcode def _load_template( self, name: str, globals: t.Optional[t.MutableMapping[str, t.Any]] ) -> "Template": if self.loader is None: raise TypeError("no loader for this environment specified") cache_key = (weakref.ref(self.loader), name) if self.cache is not None: template = self.cache.get(cache_key) if template is not None and ( not self.auto_reload or template.is_up_to_date ): # template.globals is a ChainMap, modifying it will only # affect the template, not the environment globals. if globals: template.globals.update(globals) return template template = self.loader.load(self, name, self.make_globals(globals)) if self.cache is not None: self.cache[cache_key] = template return template @internalcode def get_template( self, name: t.Union[str, "Template"], parent: t.Optional[str] = None, globals: t.Optional[t.MutableMapping[str, t.Any]] = None, ) -> "Template": """Load a template by name with :attr:`loader` and return a :class:`Template`. If the template does not exist a :exc:`TemplateNotFound` exception is raised. :param name: Name of the template to load. When loading templates from the filesystem, "/" is used as the path separator, even on Windows. :param parent: The name of the parent template importing this template. :meth:`join_path` can be used to implement name transformations with this. :param globals: Extend the environment :attr:`globals` with these extra variables available for all renders of this template. If the template has already been loaded and cached, its globals are updated with any new items. .. versionchanged:: 3.0 If a template is loaded from cache, ``globals`` will update the template's globals instead of ignoring the new values. .. versionchanged:: 2.4 If ``name`` is a :class:`Template` object it is returned unchanged. """ if isinstance(name, Template): return name if parent is not None: name = self.join_path(name, parent) return self._load_template(name, globals) @internalcode def select_template( self, names: t.Iterable[t.Union[str, "Template"]], parent: t.Optional[str] = None, globals: t.Optional[t.MutableMapping[str, t.Any]] = None, ) -> "Template": """Like :meth:`get_template`, but tries loading multiple names. If none of the names can be loaded a :exc:`TemplatesNotFound` exception is raised. :param names: List of template names to try loading in order. :param parent: The name of the parent template importing this template. :meth:`join_path` can be used to implement name transformations with this. :param globals: Extend the environment :attr:`globals` with these extra variables available for all renders of this template. If the template has already been loaded and cached, its globals are updated with any new items. .. versionchanged:: 3.0 If a template is loaded from cache, ``globals`` will update the template's globals instead of ignoring the new values. .. versionchanged:: 2.11 If ``names`` is :class:`Undefined`, an :exc:`UndefinedError` is raised instead. If no templates were found and ``names`` contains :class:`Undefined`, the message is more helpful. .. versionchanged:: 2.4 If ``names`` contains a :class:`Template` object it is returned unchanged. .. versionadded:: 2.3 """ if isinstance(names, Undefined): names._fail_with_undefined_error() if not names: raise TemplatesNotFound( message="Tried to select from an empty list of templates." ) for name in names: if isinstance(name, Template): return name if parent is not None: name = self.join_path(name, parent) try: return self._load_template(name, globals) except (TemplateNotFound, UndefinedError): pass raise TemplatesNotFound(names) # type: ignore @internalcode def get_or_select_template( self, template_name_or_list: t.Union[ str, "Template", t.List[t.Union[str, "Template"]] ], parent: t.Optional[str] = None, globals: t.Optional[t.MutableMapping[str, t.Any]] = None, ) -> "Template": """Use :meth:`select_template` if an iterable of template names is given, or :meth:`get_template` if one name is given. .. versionadded:: 2.3 """ if isinstance(template_name_or_list, (str, Undefined)): return self.get_template(template_name_or_list, parent, globals) elif isinstance(template_name_or_list, Template): return template_name_or_list return self.select_template(template_name_or_list, parent, globals) def from_string( self, source: t.Union[str, nodes.Template], globals: t.Optional[t.MutableMapping[str, t.Any]] = None, template_class: t.Optional[t.Type["Template"]] = None, ) -> "Template": """Load a template from a source string without using :attr:`loader`. :param source: Jinja source to compile into a template. :param globals: Extend the environment :attr:`globals` with these extra variables available for all renders of this template. If the template has already been loaded and cached, its globals are updated with any new items. :param template_class: Return an instance of this :class:`Template` class. """ gs = self.make_globals(globals) cls = template_class or self.template_class return cls.from_code(self, self.compile(source), gs, None) def make_globals( self, d: t.Optional[t.MutableMapping[str, t.Any]] ) -> t.MutableMapping[str, t.Any]: """Make the globals map for a template. Any given template globals overlay the environment :attr:`globals`. Returns a :class:`collections.ChainMap`. This allows any changes to a template's globals to only affect that template, while changes to the environment's globals are still reflected. However, avoid modifying any globals after a template is loaded. :param d: Dict of template-specific globals. .. versionchanged:: 3.0 Use :class:`collections.ChainMap` to always prevent mutating environment globals. """ if d is None: d = {} return ChainMap(d, self.globals) class Template: """A compiled template that can be rendered. Use the methods on :class:`Environment` to create or load templates. The environment is used to configure how templates are compiled and behave. It is also possible to create a template object directly. This is not usually recommended. The constructor takes most of the same arguments as :class:`Environment`. All templates created with the same environment arguments share the same ephemeral ``Environment`` instance behind the scenes. A template object should be considered immutable. Modifications on the object are not supported. """ #: Type of environment to create when creating a template directly #: rather than through an existing environment. environment_class: t.Type[Environment] = Environment environment: Environment globals: t.MutableMapping[str, t.Any] name: t.Optional[str] filename: t.Optional[str] blocks: t.Dict[str, t.Callable[[Context], t.Iterator[str]]] root_render_func: t.Callable[[Context], t.Iterator[str]] _module: t.Optional["TemplateModule"] _debug_info: str _uptodate: t.Optional[t.Callable[[], bool]] def __new__( cls, source: t.Union[str, nodes.Template], block_start_string: str = BLOCK_START_STRING, block_end_string: str = BLOCK_END_STRING, variable_start_string: str = VARIABLE_START_STRING, variable_end_string: str = VARIABLE_END_STRING, comment_start_string: str = COMMENT_START_STRING, comment_end_string: str = COMMENT_END_STRING, line_statement_prefix: t.Optional[str] = LINE_STATEMENT_PREFIX, line_comment_prefix: t.Optional[str] = LINE_COMMENT_PREFIX, trim_blocks: bool = TRIM_BLOCKS, lstrip_blocks: bool = LSTRIP_BLOCKS, newline_sequence: "te.Literal['\\n', '\\r\\n', '\\r']" = NEWLINE_SEQUENCE, keep_trailing_newline: bool = KEEP_TRAILING_NEWLINE, extensions: t.Sequence[t.Union[str, t.Type["Extension"]]] = (), optimized: bool = True, undefined: t.Type[Undefined] = Undefined, finalize: t.Optional[t.Callable[..., t.Any]] = None, autoescape: t.Union[bool, t.Callable[[t.Optional[str]], bool]] = False, enable_async: bool = False, ) -> t.Any: # it returns a `Template`, but this breaks the sphinx build... env = get_spontaneous_environment( cls.environment_class, # type: ignore block_start_string, block_end_string, variable_start_string, variable_end_string, comment_start_string, comment_end_string, line_statement_prefix, line_comment_prefix, trim_blocks, lstrip_blocks, newline_sequence, keep_trailing_newline, frozenset(extensions), optimized, undefined, # type: ignore finalize, autoescape, None, 0, False, None, enable_async, ) return env.from_string(source, template_class=cls) @classmethod def from_code( cls, environment: Environment, code: CodeType, globals: t.MutableMapping[str, t.Any], uptodate: t.Optional[t.Callable[[], bool]] = None, ) -> "Template": """Creates a template object from compiled code and the globals. This is used by the loaders and environment to create a template object. """ namespace = {"environment": environment, "__file__": code.co_filename} exec(code, namespace) rv = cls._from_namespace(environment, namespace, globals) rv._uptodate = uptodate return rv @classmethod def from_module_dict( cls, environment: Environment, module_dict: t.MutableMapping[str, t.Any], globals: t.MutableMapping[str, t.Any], ) -> "Template": """Creates a template object from a module. This is used by the module loader to create a template object. .. versionadded:: 2.4 """ return cls._from_namespace(environment, module_dict, globals) @classmethod def _from_namespace( cls, environment: Environment, namespace: t.MutableMapping[str, t.Any], globals: t.MutableMapping[str, t.Any], ) -> "Template": t: "Template" = object.__new__(cls) t.environment = environment t.globals = globals t.name = namespace["name"] t.filename = namespace["__file__"] t.blocks = namespace["blocks"] # render function and module t.root_render_func = namespace["root"] # type: ignore t._module = None # debug and loader helpers t._debug_info = namespace["debug_info"] t._uptodate = None # store the reference namespace["environment"] = environment namespace["__jinja_template__"] = t return t def render(self, *args: t.Any, **kwargs: t.Any) -> str: """This method accepts the same arguments as the `dict` constructor: A dict, a dict subclass or some keyword arguments. If no arguments are given the context will be empty. These two calls do the same:: template.render(knights='that say nih') template.render({'knights': 'that say nih'}) This will return the rendered template as a string. """ if self.environment.is_async: import asyncio close = False try: loop = asyncio.get_running_loop() except RuntimeError: loop = asyncio.new_event_loop() close = True try: return loop.run_until_complete(self.render_async(*args, **kwargs)) finally: if close: loop.close() ctx = self.new_context(dict(*args, **kwargs)) try: return self.environment.concat(self.root_render_func(ctx)) # type: ignore except Exception: self.environment.handle_exception() async def render_async(self, *args: t.Any, **kwargs: t.Any) -> str: """This works similar to :meth:`render` but returns a coroutine that when awaited returns the entire rendered template string. This requires the async feature to be enabled. Example usage:: await template.render_async(knights='that say nih; asynchronously') """ if not self.environment.is_async: raise RuntimeError( "The environment was not created with async mode enabled." ) ctx = self.new_context(dict(*args, **kwargs)) try: return self.environment.concat( # type: ignore [n async for n in self.root_render_func(ctx)] # type: ignore ) except Exception: return self.environment.handle_exception() def stream(self, *args: t.Any, **kwargs: t.Any) -> "TemplateStream": """Works exactly like :meth:`generate` but returns a :class:`TemplateStream`. """ return TemplateStream(self.generate(*args, **kwargs)) def generate(self, *args: t.Any, **kwargs: t.Any) -> t.Iterator[str]: """For very large templates it can be useful to not render the whole template at once but evaluate each statement after another and yield piece for piece. This method basically does exactly that and returns a generator that yields one item after another as strings. It accepts the same arguments as :meth:`render`. """ if self.environment.is_async: import asyncio async def to_list() -> t.List[str]: return [x async for x in self.generate_async(*args, **kwargs)] yield from asyncio.run(to_list()) return ctx = self.new_context(dict(*args, **kwargs)) try: yield from self.root_render_func(ctx) # type: ignore except Exception: yield self.environment.handle_exception() async def generate_async( self, *args: t.Any, **kwargs: t.Any ) -> t.AsyncIterator[str]: """An async version of :meth:`generate`. Works very similarly but returns an async iterator instead. """ if not self.environment.is_async: raise RuntimeError( "The environment was not created with async mode enabled." ) ctx = self.new_context(dict(*args, **kwargs)) try: async for event in self.root_render_func(ctx): # type: ignore yield event except Exception: yield self.environment.handle_exception() def new_context( self, vars: t.Optional[t.Dict[str, t.Any]] = None, shared: bool = False, locals: t.Optional[t.Mapping[str, t.Any]] = None, ) -> Context: """Create a new :class:`Context` for this template. The vars provided will be passed to the template. Per default the globals are added to the context. If shared is set to `True` the data is passed as is to the context without adding the globals. `locals` can be a dict of local variables for internal usage. """ return new_context( self.environment, self.name, self.blocks, vars, shared, self.globals, locals ) def make_module( self, vars: t.Optional[t.Dict[str, t.Any]] = None, shared: bool = False, locals: t.Optional[t.Mapping[str, t.Any]] = None, ) -> "TemplateModule": """This method works like the :attr:`module` attribute when called without arguments but it will evaluate the template on every call rather than caching it. It's also possible to provide a dict which is then used as context. The arguments are the same as for the :meth:`new_context` method. """ ctx = self.new_context(vars, shared, locals) return TemplateModule(self, ctx) async def make_module_async( self, vars: t.Optional[t.Dict[str, t.Any]] = None, shared: bool = False, locals: t.Optional[t.Mapping[str, t.Any]] = None, ) -> "TemplateModule": """As template module creation can invoke template code for asynchronous executions this method must be used instead of the normal :meth:`make_module` one. Likewise the module attribute becomes unavailable in async mode. """ ctx = self.new_context(vars, shared, locals) return TemplateModule( self, ctx, [x async for x in self.root_render_func(ctx)] # type: ignore ) @internalcode def _get_default_module(self, ctx: t.Optional[Context] = None) -> "TemplateModule": """If a context is passed in, this means that the template was imported. Imported templates have access to the current template's globals by default, but they can only be accessed via the context during runtime. If there are new globals, we need to create a new module because the cached module is already rendered and will not have access to globals from the current context. This new module is not cached because the template can be imported elsewhere, and it should have access to only the current template's globals. """ if self.environment.is_async: raise RuntimeError("Module is not available in async mode.") if ctx is not None: keys = ctx.globals_keys - self.globals.keys() if keys: return self.make_module({k: ctx.parent[k] for k in keys}) if self._module is None: self._module = self.make_module() return self._module async def _get_default_module_async( self, ctx: t.Optional[Context] = None ) -> "TemplateModule": if ctx is not None: keys = ctx.globals_keys - self.globals.keys() if keys: return await self.make_module_async({k: ctx.parent[k] for k in keys}) if self._module is None: self._module = await self.make_module_async() return self._module @property def module(self) -> "TemplateModule": """The template as module. This is used for imports in the template runtime but is also useful if one wants to access exported template variables from the Python layer: >>> t = Template('{% macro foo() %}42{% endmacro %}23') >>> str(t.module) '23' >>> t.module.foo() == u'42' True This attribute is not available if async mode is enabled. """ return self._get_default_module() def get_corresponding_lineno(self, lineno: int) -> int: """Return the source line number of a line number in the generated bytecode as they are not in sync. """ for template_line, code_line in reversed(self.debug_info): if code_line <= lineno: return template_line return 1 @property def is_up_to_date(self) -> bool: """If this variable is `False` there is a newer version available.""" if self._uptodate is None: return True return self._uptodate() @property def debug_info(self) -> t.List[t.Tuple[int, int]]: """The debug info mapping.""" if self._debug_info: return [ tuple(map(int, x.split("="))) # type: ignore for x in self._debug_info.split("&") ] return [] def __repr__(self) -> str: if self.name is None: name = f"memory:{id(self):x}" else: name = repr(self.name) return f"<{type(self).__name__} {name}>" class TemplateModule: """Represents an imported template. All the exported names of the template are available as attributes on this object. Additionally converting it into a string renders the contents. """ def __init__( self, template: Template, context: Context, body_stream: t.Optional[t.Iterable[str]] = None, ) -> None: if body_stream is None: if context.environment.is_async: raise RuntimeError( "Async mode requires a body stream to be passed to" " a template module. Use the async methods of the" " API you are using." ) body_stream = list(template.root_render_func(context)) # type: ignore self._body_stream = body_stream self.__dict__.update(context.get_exported()) self.__name__ = template.name def __html__(self) -> Markup: return Markup(concat(self._body_stream)) def __str__(self) -> str: return concat(self._body_stream) def __repr__(self) -> str: if self.__name__ is None: name = f"memory:{id(self):x}" else: name = repr(self.__name__) return f"<{type(self).__name__} {name}>" class TemplateExpression: """The :meth:`jinja2.Environment.compile_expression` method returns an instance of this object. It encapsulates the expression-like access to the template with an expression it wraps. """ def __init__(self, template: Template, undefined_to_none: bool) -> None: self._template = template self._undefined_to_none = undefined_to_none def __call__(self, *args: t.Any, **kwargs: t.Any) -> t.Optional[t.Any]: context = self._template.new_context(dict(*args, **kwargs)) consume(self._template.root_render_func(context)) # type: ignore rv = context.vars["result"] if self._undefined_to_none and isinstance(rv, Undefined): rv = None return rv class TemplateStream: """A template stream works pretty much like an ordinary python generator but it can buffer multiple items to reduce the number of total iterations. Per default the output is unbuffered which means that for every unbuffered instruction in the template one string is yielded. If buffering is enabled with a buffer size of 5, five items are combined into a new string. This is mainly useful if you are streaming big templates to a client via WSGI which flushes after each iteration. """ def __init__(self, gen: t.Iterator[str]) -> None: self._gen = gen self.disable_buffering() def dump( self, fp: t.Union[str, t.IO], encoding: t.Optional[str] = None, errors: t.Optional[str] = "strict", ) -> None: """Dump the complete stream into a file or file-like object. Per default strings are written, if you want to encode before writing specify an `encoding`. Example usage:: Template('Hello {{ name }}!').stream(name='foo').dump('hello.html') """ close = False if isinstance(fp, str): if encoding is None: encoding = "utf-8" fp = open(fp, "wb") close = True try: if encoding is not None: iterable = (x.encode(encoding, errors) for x in self) # type: ignore else: iterable = self # type: ignore if hasattr(fp, "writelines"): fp.writelines(iterable) else: for item in iterable: fp.write(item) finally: if close: fp.close() def disable_buffering(self) -> None: """Disable the output buffering.""" self._next = partial(next, self._gen) self.buffered = False def _buffered_generator(self, size: int) -> t.Iterator[str]: buf: t.List[str] = [] c_size = 0 push = buf.append while True: try: while c_size < size: c = next(self._gen) push(c) if c: c_size += 1 except StopIteration: if not c_size: return yield concat(buf) del buf[:] c_size = 0 def enable_buffering(self, size: int = 5) -> None: """Enable buffering. Buffer `size` items before yielding them.""" if size <= 1: raise ValueError("buffer size too small") self.buffered = True self._next = partial(next, self._buffered_generator(size)) def __iter__(self) -> "TemplateStream": return self def __next__(self) -> str: return self._next() # type: ignore # hook in default template class. if anyone reads this comment: ignore that # it's possible to use custom templates ;-) Environment.template_class = Template