EVOLUTION-MANAGER

Edit File: environment.py

# -*- coding: utf-8 -*- """ jinja2.environment ~~~~~~~~~~~~~~~~~~ Provides a class that holds runtime and parsing time options. :copyright: (c) 2010 by the Jinja Team. :license: BSD, see LICENSE for more details. """ import os import sys from jinja2 import nodes from jinja2.defaults import 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, NEWLINE_SEQUENCE, \ DEFAULT_FILTERS, DEFAULT_TESTS, DEFAULT_NAMESPACE, \ KEEP_TRAILING_NEWLINE, LSTRIP_BLOCKS from jinja2.lexer import get_lexer, TokenStream from jinja2.parser import Parser from jinja2.nodes import EvalContext from jinja2.optimizer import optimize from jinja2.compiler import generate from jinja2.runtime import Undefined, new_context from jinja2.exceptions import TemplateSyntaxError, TemplateNotFound, \ TemplatesNotFound, TemplateRuntimeError from jinja2.utils import import_string, LRUCache, Markup, missing, \ concat, consume, internalcode from jinja2._compat import imap, ifilter, string_types, iteritems, \ text_type, reraise, implements_iterator, implements_to_string, \ get_next, encode_filename, PY2, PYPY from functools import reduce # for direct template usage we have up to ten living environments _spontaneous_environments = LRUCache(10) # the function to create jinja traceback objects. This is dynamically # imported on the first exception in the exception handler. _make_traceback = None def get_spontaneous_environment(*args): """Return a new spontaneous environment. A spontaneous environment is an unnamed and unaccessible (in theory) environment that is used for templates generated from a string and not from the file system. """ try: env = _spontaneous_environments.get(args) except TypeError: return Environment(*args) if env is not None: return env _spontaneous_environments[args] = env = Environment(*args) env.shared = True return env def create_cache(size): """Return the cache class for the given size.""" if size == 0: return None if size < 0: return {} return LRUCache(size) def copy_cache(cache): """Create an empty copy of the given cache.""" if cache is None: return None elif type(cache) is dict: return {} return LRUCache(cache.capacity) def load_extensions(environment, extensions): """Load the extensions from the list and bind it to the environment. Returns a dict of instantiated environments. """ result = {} for extension in extensions: if isinstance(extension, string_types): extension = import_string(extension) result[extension.identifier] = extension(environment) return result def _environment_sanity_check(environment): """Perform a sanity check on the environment.""" assert issubclass(environment.undefined, Undefined), 'undefined must ' \ 'be a subclass of undefined because filters depend on it.' 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 set to unknown line ending string.' return environment class Environment(object): 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 the possible initialization parameters: `block_start_string` The string marking the begin 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 begin 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 begin 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 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 auto escaping see :class:`~jinja2.utils.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 ``50`` which means that if more than 50 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. `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. """ #: 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 = None #: shared environments have this set to `True`. A shared environment #: must not be modified shared = False #: these are currently EXPERIMENTAL undocumented features. exception_handler = None exception_formatter = None def __init__(self, block_start_string=BLOCK_START_STRING, block_end_string=BLOCK_END_STRING, variable_start_string=VARIABLE_START_STRING, variable_end_string=VARIABLE_END_STRING, comment_start_string=COMMENT_START_STRING, comment_end_string=COMMENT_END_STRING, line_statement_prefix=LINE_STATEMENT_PREFIX, line_comment_prefix=LINE_COMMENT_PREFIX, trim_blocks=TRIM_BLOCKS, lstrip_blocks=LSTRIP_BLOCKS, newline_sequence=NEWLINE_SEQUENCE, keep_trailing_newline=KEEP_TRAILING_NEWLINE, extensions=(), optimized=True, undefined=Undefined, finalize=None, autoescape=False, loader=None, cache_size=50, auto_reload=True, bytecode_cache=None): # !!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 = 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 # load extensions self.extensions = load_extensions(self, extensions) _environment_sanity_check(self) def add_extension(self, extension): """Adds an extension after the environment was created. .. versionadded:: 2.5 """ self.extensions.update(load_extensions(self, [extension])) def extend(self, **attributes): """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 iteritems(attributes): if not hasattr(self, key): setattr(self, key, value) def overlay(self, block_start_string=missing, block_end_string=missing, variable_start_string=missing, variable_end_string=missing, comment_start_string=missing, comment_end_string=missing, line_statement_prefix=missing, line_comment_prefix=missing, trim_blocks=missing, lstrip_blocks=missing, extensions=missing, optimized=missing, undefined=missing, finalize=missing, autoescape=missing, loader=missing, cache_size=missing, auto_reload=missing, bytecode_cache=missing): """Create a new overlay environment that shares all the data with the current environment except of 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. """ args = dict(locals()) del args['self'], args['cache_size'], args['extensions'] rv = object.__new__(self.__class__) rv.__dict__.update(self.__dict__) rv.overlayed = True rv.linked_to = self for key, value in iteritems(args): 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 iteritems(self.extensions): rv.extensions[key] = value.bind(rv) if extensions is not missing: rv.extensions.update(load_extensions(rv, extensions)) return _environment_sanity_check(rv) lexer = property(get_lexer, doc="The lexer for this environment.") def iter_extensions(self): """Iterates over the extensions by priority.""" return iter(sorted(self.extensions.values(), key=lambda x: x.priority)) def getitem(self, obj, argument): """Get an item or attribute of an object but prefer the item.""" try: return obj[argument] except (TypeError, LookupError): if isinstance(argument, string_types): 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, attribute): """Get an item or attribute of an object but prefer the attribute. Unlike :meth:`getitem` the attribute *must* be a bytestring. """ try: return getattr(obj, attribute) except AttributeError: pass try: return obj[attribute] except (TypeError, LookupError, AttributeError): return self.undefined(obj=obj, name=attribute) def call_filter(self, name, value, args=None, kwargs=None, context=None, eval_ctx=None): """Invokes a filter on a value the same way the compiler does it. .. versionadded:: 2.7 """ func = self.filters.get(name) if func is None: raise TemplateRuntimeError('no filter named %r' % name) args = [value] + list(args or ()) if getattr(func, 'contextfilter', False): if context is None: raise TemplateRuntimeError('Attempted to invoke context ' 'filter without context') args.insert(0, context) elif getattr(func, 'evalcontextfilter', False): 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 getattr(func, 'environmentfilter', False): args.insert(0, self) return func(*args, **(kwargs or {})) def call_test(self, name, value, args=None, kwargs=None): """Invokes a test on a value the same way the compiler does it. .. versionadded:: 2.7 """ func = self.tests.get(name) if func is None: raise TemplateRuntimeError('no test named %r' % name) return func(value, *(args or ()), **(kwargs or {})) @internalcode def parse(self, source, name=None, filename=None): """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 Jinja2 extensions <writing-extensions>` this gives you a good overview of the node tree generated. """ try: return self._parse(source, name, filename) except TemplateSyntaxError: exc_info = sys.exc_info() self.handle_exception(exc_info, source_hint=source) def _parse(self, source, name, filename): """Internal parsing function used by `parse` and `compile`.""" return Parser(self, source, name, encode_filename(filename)).parse() def lex(self, source, name=None, filename=None): """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 = text_type(source) try: return self.lexer.tokeniter(source, name, filename) except TemplateSyntaxError: exc_info = sys.exc_info() self.handle_exception(exc_info, source_hint=source) def preprocess(self, source, name=None, filename=None): """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(), text_type(source)) def _tokenize(self, source, name, filename=None, state=None): """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) if not isinstance(stream, TokenStream): stream = TokenStream(stream, name, filename) return stream def _generate(self, source, name, filename, defer_init=False): """Internal hook that can be overridden to hook a different generate method in. .. versionadded:: 2.5 """ return generate(source, self, name, filename, defer_init=defer_init) def _compile(self, source, filename): """Internal hook that can be overridden to hook a different compile method in. .. versionadded:: 2.5 """ return compile(source, filename, 'exec') @internalcode def compile(self, source, name=None, filename=None, raw=False, defer_init=False): """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, string_types): source_hint = source source = self._parse(source, name, filename) if self.optimized: source = optimize(source, self) source = self._generate(source, name, filename, defer_init=defer_init) if raw: return source if filename is None: filename = '<template>' else: filename = encode_filename(filename) return self._compile(source, filename) except TemplateSyntaxError: exc_info = sys.exc_info() self.handle_exception(exc_info, source_hint=source) def compile_expression(self, source, undefined_to_none=True): """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') exc_info = None 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: exc_info = sys.exc_info() if exc_info is not None: self.handle_exception(exc_info, source_hint=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, extensions=None, filter_func=None, zip='deflated', log_function=None, ignore_errors=True, py_compile=False): """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 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. If `py_compile` is set to `True` .pyc files will be written to the target instead of standard .py files. This flag does not do anything on pypy and Python 3 where pyc files are not picked up by itself and don't give much benefit. .. versionadded:: 2.4 """ from jinja2.loaders import ModuleLoader if log_function is None: log_function = lambda x: None if py_compile: if not PY2 or PYPY: from warnings import warn warn(Warning('py_compile has no effect on pypy or Python 3')) py_compile = False else: import imp, marshal py_header = imp.get_magic() + \ u'\xff\xff\xff\xff'.encode('iso-8859-15') # Python 3.3 added a source filesize to the header if sys.version_info >= (3, 3): py_header += u'\x00\x00\x00\x00'.encode('iso-8859-15') def write_file(filename, data, mode): if zip: info = ZipInfo(filename) info.external_attr = 0o755 << 16 zip_file.writestr(info, data) else: f = open(os.path.join(target, filename), mode) try: f.write(data) finally: f.close() 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('Compiling into Zip archive "%s"' % target) else: if not os.path.isdir(target): os.makedirs(target) log_function('Compiling into folder "%s"' % target) 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('Could not compile "%s": %s' % (name, e)) continue filename = ModuleLoader.get_module_filename(name) if py_compile: c = self._compile(code, encode_filename(filename)) write_file(filename + 'c', py_header + marshal.dumps(c), 'wb') log_function('Byte-compiled "%s" as %s' % (name, filename + 'c')) else: write_file(filename, code, 'w') log_function('Compiled "%s" as %s' % (name, filename)) finally: if zip: zip_file.close() log_function('Finished compiling templates') def list_templates(self, extensions=None, filter_func=None): """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 """ x = 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') filter_func = lambda x: '.' in x and \ x.rsplit('.', 1)[1] in extensions if filter_func is not None: x = ifilter(filter_func, x) return x def handle_exception(self, exc_info=None, rendered=False, source_hint=None): """Exception handling helper. This is used internally to either raise rewritten exceptions or return a rendered traceback for the template. """ global _make_traceback if exc_info is None: exc_info = sys.exc_info() # the debugging module is imported when it's used for the first time. # we're doing a lot of stuff there and for applications that do not # get any exceptions in template rendering there is no need to load # all of that. if _make_traceback is None: from jinja2.debug import make_traceback as _make_traceback traceback = _make_traceback(exc_info, source_hint) if rendered and self.exception_formatter is not None: return self.exception_formatter(traceback) if self.exception_handler is not None: self.exception_handler(traceback) exc_type, exc_value, tb = traceback.standard_exc_info reraise(exc_type, exc_value, tb) def join_path(self, template, parent): """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, globals): if self.loader is None: raise TypeError('no loader for this environment specified') if self.cache is not None: template = self.cache.get(name) if template is not None and (not self.auto_reload or \ template.is_up_to_date): return template template = self.loader.load(self, name, globals) if self.cache is not None: self.cache[name] = template return template @internalcode def get_template(self, name, parent=None, globals=None): """Load a template from the loader. If a loader is configured this method ask the loader for the template and returns a :class:`Template`. If the `parent` parameter is not `None`, :meth:`join_path` is called to get the real template name before loading. The `globals` parameter can be used to provide template wide globals. These variables are available in the context at render time. If the template does not exist a :exc:`TemplateNotFound` exception is raised. .. versionchanged:: 2.4 If `name` is a :class:`Template` object it is returned from the function unchanged. """ if isinstance(name, Template): return name if parent is not None: name = self.join_path(name, parent) return self._load_template(name, self.make_globals(globals)) @internalcode def select_template(self, names, parent=None, globals=None): """Works like :meth:`get_template` but tries a number of templates before it fails. If it cannot find any of the templates, it will raise a :exc:`TemplatesNotFound` exception. .. versionadded:: 2.3 .. versionchanged:: 2.4 If `names` contains a :class:`Template` object it is returned from the function unchanged. """ if not names: raise TemplatesNotFound(message=u'Tried to select from an empty list ' u'of templates.') globals = self.make_globals(globals) 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: pass raise TemplatesNotFound(names) @internalcode def get_or_select_template(self, template_name_or_list, parent=None, globals=None): """Does a typecheck and dispatches to :meth:`select_template` if an iterable of template names is given, otherwise to :meth:`get_template`. .. versionadded:: 2.3 """ if isinstance(template_name_or_list, string_types): 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, globals=None, template_class=None): """Load a template from a string. This parses the source given and returns a :class:`Template` object. """ globals = self.make_globals(globals) cls = template_class or self.template_class return cls.from_code(self, self.compile(source), globals, None) def make_globals(self, d): """Return a dict for the globals.""" if not d: return self.globals return dict(self.globals, **d) class Template(object): """The central template object. This class represents a compiled template and is used to evaluate it. Normally the template object is generated from an :class:`Environment` but it also has a constructor that makes it possible to create a template instance directly using the constructor. It takes the same arguments as the environment constructor but it's not possible to specify a loader. Every template object has a few methods and members that are guaranteed to exist. However it's important that a template object should be considered immutable. Modifications on the object are not supported. Template objects created from the constructor rather than an environment do have an `environment` attribute that points to a temporary environment that is probably shared with other templates created with the constructor and compatible settings. >>> template = Template('Hello {{ name }}!') >>> template.render(name='John Doe') u'Hello John Doe!' >>> stream = template.stream(name='John Doe') >>> stream.next() u'Hello John Doe!' >>> stream.next() Traceback (most recent call last): ... StopIteration """ def __new__(cls, source, block_start_string=BLOCK_START_STRING, block_end_string=BLOCK_END_STRING, variable_start_string=VARIABLE_START_STRING, variable_end_string=VARIABLE_END_STRING, comment_start_string=COMMENT_START_STRING, comment_end_string=COMMENT_END_STRING, line_statement_prefix=LINE_STATEMENT_PREFIX, line_comment_prefix=LINE_COMMENT_PREFIX, trim_blocks=TRIM_BLOCKS, lstrip_blocks=LSTRIP_BLOCKS, newline_sequence=NEWLINE_SEQUENCE, keep_trailing_newline=KEEP_TRAILING_NEWLINE, extensions=(), optimized=True, undefined=Undefined, finalize=None, autoescape=False): env = get_spontaneous_environment( 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, finalize, autoescape, None, 0, False, None) return env.from_string(source, template_class=cls) @classmethod def from_code(cls, environment, code, globals, uptodate=None): """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, module_dict, globals): """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, namespace, globals): t = 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'] 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, **kwargs): """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 unicode string. """ vars = dict(*args, **kwargs) try: return concat(self.root_render_func(self.new_context(vars))) except Exception: exc_info = sys.exc_info() return self.environment.handle_exception(exc_info, True) def stream(self, *args, **kwargs): """Works exactly like :meth:`generate` but returns a :class:`TemplateStream`. """ return TemplateStream(self.generate(*args, **kwargs)) def generate(self, *args, **kwargs): """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 unicode strings. It accepts the same arguments as :meth:`render`. """ vars = dict(*args, **kwargs) try: for event in self.root_render_func(self.new_context(vars)): yield event except Exception: exc_info = sys.exc_info() else: return yield self.environment.handle_exception(exc_info, True) def new_context(self, vars=None, shared=False, locals=None): """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 it 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=None, shared=False, locals=None): """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. """ return TemplateModule(self, self.new_context(vars, shared, locals)) @property def module(self): """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') >>> unicode(t.module) u'23' >>> t.module.foo() u'42' """ if self._module is not None: return self._module self._module = rv = self.make_module() return rv def get_corresponding_lineno(self, lineno): """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): """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): """The debug info mapping.""" return [tuple(imap(int, x.split('='))) for x in self._debug_info.split('&')] def __repr__(self): if self.name is None: name = 'memory:%x' % id(self) else: name = repr(self.name) return '<%s %s>' % (self.__class__.__name__, name) @implements_to_string class TemplateModule(object): """Represents an imported template. All the exported names of the template are available as attributes on this object. Additionally converting it into an unicode- or bytestrings renders the contents. """ def __init__(self, template, context): self._body_stream = list(template.root_render_func(context)) self.__dict__.update(context.get_exported()) self.__name__ = template.name def __html__(self): return Markup(concat(self._body_stream)) def __str__(self): return concat(self._body_stream) def __repr__(self): if self.__name__ is None: name = 'memory:%x' % id(self) else: name = repr(self.__name__) return '<%s %s>' % (self.__class__.__name__, name) class TemplateExpression(object): """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, undefined_to_none): self._template = template self._undefined_to_none = undefined_to_none def __call__(self, *args, **kwargs): context = self._template.new_context(dict(*args, **kwargs)) consume(self._template.root_render_func(context)) rv = context.vars['result'] if self._undefined_to_none and isinstance(rv, Undefined): rv = None return rv @implements_iterator class TemplateStream(object): """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 unicode string is yielded. If buffering is enabled with a buffer size of 5, five items are combined into a new unicode 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): self._gen = gen self.disable_buffering() def dump(self, fp, encoding=None, errors='strict'): """Dump the complete stream into a file or file-like object. Per default unicode 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, string_types): fp = open(fp, encoding is None and 'w' or 'wb') close = True try: if encoding is not None: iterable = (x.encode(encoding, errors) for x in self) else: iterable = self if hasattr(fp, 'writelines'): fp.writelines(iterable) else: for item in iterable: fp.write(item) finally: if close: fp.close() def disable_buffering(self): """Disable the output buffering.""" self._next = get_next(self._gen) self.buffered = False def enable_buffering(self, size=5): """Enable buffering. Buffer `size` items before yielding them.""" if size <= 1: raise ValueError('buffer size too small') def generator(next): buf = [] c_size = 0 push = buf.append while 1: try: while c_size < size: c = next() push(c) if c: c_size += 1 except StopIteration: if not c_size: return yield concat(buf) del buf[:] c_size = 0 self.buffered = True self._next = get_next(generator(get_next(self._gen))) def __iter__(self): return self def __next__(self): return self._next() # hook in default template class. if anyone reads this comment: ignore that # it's possible to use custom templates ;-) Environment.template_class = Template