1 # -*- coding: utf-8 -*-
6 Provides a class that holds runtime and parsing time options.
8 :copyright: (c) 2010 by the Jinja Team.
9 :license: BSD, see LICENSE for more details.
13 from jinja2 import nodes
14 from jinja2.defaults import *
15 from jinja2.lexer import get_lexer, TokenStream
16 from jinja2.parser import Parser
17 from jinja2.optimizer import optimize
18 from jinja2.compiler import generate
19 from jinja2.runtime import Undefined, new_context
20 from jinja2.exceptions import TemplateSyntaxError, TemplateNotFound, \
22 from jinja2.utils import import_string, LRUCache, Markup, missing, \
23 concat, consume, internalcode, _encode_filename
26 # for direct template usage we have up to ten living environments
27 _spontaneous_environments = LRUCache(10)
29 # the function to create jinja traceback objects. This is dynamically
30 # imported on the first exception in the exception handler.
31 _make_traceback = None
34 def get_spontaneous_environment(*args):
35 """Return a new spontaneous environment. A spontaneous environment is an
36 unnamed and unaccessible (in theory) environment that is used for
37 templates generated from a string and not from the file system.
40 env = _spontaneous_environments.get(args)
42 return Environment(*args)
45 _spontaneous_environments[args] = env = Environment(*args)
50 def create_cache(size):
51 """Return the cache class for the given size."""
59 def copy_cache(cache):
60 """Create an empty copy of the given cache."""
63 elif type(cache) is dict:
65 return LRUCache(cache.capacity)
68 def load_extensions(environment, extensions):
69 """Load the extensions from the list and bind it to the environment.
70 Returns a dict of instanciated environments.
73 for extension in extensions:
74 if isinstance(extension, basestring):
75 extension = import_string(extension)
76 result[extension.identifier] = extension(environment)
80 def _environment_sanity_check(environment):
81 """Perform a sanity check on the environment."""
82 assert issubclass(environment.undefined, Undefined), 'undefined must ' \
83 'be a subclass of undefined because filters depend on it.'
84 assert environment.block_start_string != \
85 environment.variable_start_string != \
86 environment.comment_start_string, 'block, variable and comment ' \
87 'start strings must be different'
88 assert environment.newline_sequence in ('\r', '\r\n', '\n'), \
89 'newline_sequence set to unknown line ending string.'
93 class Environment(object):
94 r"""The core component of Jinja is the `Environment`. It contains
95 important shared variables like configuration, filters, tests,
96 globals and others. Instances of this class may be modified if
97 they are not shared and if no template was loaded so far.
98 Modifications on environments after the first template was loaded
99 will lead to surprising effects and undefined behavior.
101 Here the possible initialization parameters:
104 The string marking the begin of a block. Defaults to ``'{%'``.
107 The string marking the end of a block. Defaults to ``'%}'``.
109 `variable_start_string`
110 The string marking the begin of a print statement.
111 Defaults to ``'{{'``.
113 `variable_end_string`
114 The string marking the end of a print statement. Defaults to
117 `comment_start_string`
118 The string marking the begin of a comment. Defaults to ``'{#'``.
121 The string marking the end of a comment. Defaults to ``'#}'``.
123 `line_statement_prefix`
124 If given and a string, this will be used as prefix for line based
125 statements. See also :ref:`line-statements`.
127 `line_comment_prefix`
128 If given and a string, this will be used as prefix for line based
129 based comments. See also :ref:`line-statements`.
131 .. versionadded:: 2.2
134 If this is set to ``True`` the first newline after a block is
135 removed (block, not variable tag!). Defaults to `False`.
138 The sequence that starts a newline. Must be one of ``'\r'``,
139 ``'\n'`` or ``'\r\n'``. The default is ``'\n'`` which is a
140 useful default for Linux and OS X systems as well as web
144 List of Jinja extensions to use. This can either be import paths
145 as strings or extension classes. For more information have a
146 look at :ref:`the extensions documentation <jinja-extensions>`.
149 should the optimizer be enabled? Default is `True`.
152 :class:`Undefined` or a subclass of it that is used to represent
153 undefined values in the template.
156 A callable that can be used to process the result of a variable
157 expression before it is output. For example one can convert
158 `None` implicitly into an empty string here.
161 If set to true the XML/HTML autoescaping feature is enabled by
162 default. For more details about auto escaping see
163 :class:`~jinja2.utils.Markup`. As of Jinja 2.4 this can also
164 be a callable that is passed the template name and has to
165 return `True` or `False` depending on autoescape should be
168 .. versionchanged:: 2.4
169 `autoescape` can now be a function
172 The template loader for this environment.
175 The size of the cache. Per default this is ``50`` which means
176 that if more than 50 templates are loaded the loader will clean
177 out the least recently used template. If the cache size is set to
178 ``0`` templates are recompiled all the time, if the cache size is
179 ``-1`` the cache will not be cleaned.
182 Some loaders load templates from locations where the template
183 sources may change (ie: file system or database). If
184 `auto_reload` is set to `True` (default) every time a template is
185 requested the loader checks if the source changed and if yes, it
186 will reload the template. For higher performance it's possible to
190 If set to a bytecode cache object, this object will provide a
191 cache for the internal Jinja bytecode so that templates don't
192 have to be parsed if they were not changed.
194 See :ref:`bytecode-cache` for more information.
197 #: if this environment is sandboxed. Modifying this variable won't make
198 #: the environment sandboxed though. For a real sandboxed environment
199 #: have a look at jinja2.sandbox
202 #: True if the environment is just an overlay
205 #: the environment this environment is linked to if it is an overlay
208 #: shared environments have this set to `True`. A shared environment
209 #: must not be modified
212 #: these are currently EXPERIMENTAL undocumented features.
213 exception_handler = None
214 exception_formatter = None
217 block_start_string=BLOCK_START_STRING,
218 block_end_string=BLOCK_END_STRING,
219 variable_start_string=VARIABLE_START_STRING,
220 variable_end_string=VARIABLE_END_STRING,
221 comment_start_string=COMMENT_START_STRING,
222 comment_end_string=COMMENT_END_STRING,
223 line_statement_prefix=LINE_STATEMENT_PREFIX,
224 line_comment_prefix=LINE_COMMENT_PREFIX,
225 trim_blocks=TRIM_BLOCKS,
226 newline_sequence=NEWLINE_SEQUENCE,
235 bytecode_cache=None):
236 # !!Important notice!!
237 # The constructor accepts quite a few arguments that should be
238 # passed by keyword rather than position. However it's important to
239 # not change the order of arguments because it's used at least
240 # internally in those cases:
241 # - spontaneus environments (i18n extension and Template)
243 # If parameter changes are required only add parameters at the end
244 # and don't change the arguments (or the defaults!) of the arguments
247 # lexer / parser information
248 self.block_start_string = block_start_string
249 self.block_end_string = block_end_string
250 self.variable_start_string = variable_start_string
251 self.variable_end_string = variable_end_string
252 self.comment_start_string = comment_start_string
253 self.comment_end_string = comment_end_string
254 self.line_statement_prefix = line_statement_prefix
255 self.line_comment_prefix = line_comment_prefix
256 self.trim_blocks = trim_blocks
257 self.newline_sequence = newline_sequence
259 # runtime information
260 self.undefined = undefined
261 self.optimized = optimized
262 self.finalize = finalize
263 self.autoescape = autoescape
266 self.filters = DEFAULT_FILTERS.copy()
267 self.tests = DEFAULT_TESTS.copy()
268 self.globals = DEFAULT_NAMESPACE.copy()
270 # set the loader provided
272 self.bytecode_cache = None
273 self.cache = create_cache(cache_size)
274 self.bytecode_cache = bytecode_cache
275 self.auto_reload = auto_reload
278 self.extensions = load_extensions(self, extensions)
280 _environment_sanity_check(self)
282 def add_extension(self, extension):
283 """Adds an extension after the environment was created.
285 .. versionadded:: 2.5
287 self.extensions.update(load_extensions(self, [extension]))
289 def extend(self, **attributes):
290 """Add the items to the instance of the environment if they do not exist
291 yet. This is used by :ref:`extensions <writing-extensions>` to register
292 callbacks and configuration values without breaking inheritance.
294 for key, value in attributes.iteritems():
295 if not hasattr(self, key):
296 setattr(self, key, value)
298 def overlay(self, block_start_string=missing, block_end_string=missing,
299 variable_start_string=missing, variable_end_string=missing,
300 comment_start_string=missing, comment_end_string=missing,
301 line_statement_prefix=missing, line_comment_prefix=missing,
302 trim_blocks=missing, extensions=missing, optimized=missing,
303 undefined=missing, finalize=missing, autoescape=missing,
304 loader=missing, cache_size=missing, auto_reload=missing,
305 bytecode_cache=missing):
306 """Create a new overlay environment that shares all the data with the
307 current environment except of cache and the overridden attributes.
308 Extensions cannot be removed for an overlayed environment. An overlayed
309 environment automatically gets all the extensions of the environment it
310 is linked to plus optional extra extensions.
312 Creating overlays should happen after the initial environment was set
313 up completely. Not all attributes are truly linked, some are just
314 copied over so modifications on the original environment may not shine
317 args = dict(locals())
318 del args['self'], args['cache_size'], args['extensions']
320 rv = object.__new__(self.__class__)
321 rv.__dict__.update(self.__dict__)
325 for key, value in args.iteritems():
326 if value is not missing:
327 setattr(rv, key, value)
329 if cache_size is not missing:
330 rv.cache = create_cache(cache_size)
332 rv.cache = copy_cache(self.cache)
335 for key, value in self.extensions.iteritems():
336 rv.extensions[key] = value.bind(rv)
337 if extensions is not missing:
338 rv.extensions.update(load_extensions(extensions))
340 return _environment_sanity_check(rv)
342 lexer = property(get_lexer, doc="The lexer for this environment.")
344 def iter_extensions(self):
345 """Iterates over the extensions by priority."""
346 return iter(sorted(self.extensions.values(),
347 key=lambda x: x.priority))
349 def getitem(self, obj, argument):
350 """Get an item or attribute of an object but prefer the item."""
353 except (TypeError, LookupError):
354 if isinstance(argument, basestring):
361 return getattr(obj, attr)
362 except AttributeError:
364 return self.undefined(obj=obj, name=argument)
366 def getattr(self, obj, attribute):
367 """Get an item or attribute of an object but prefer the attribute.
368 Unlike :meth:`getitem` the attribute *must* be a bytestring.
371 return getattr(obj, attribute)
372 except AttributeError:
375 return obj[attribute]
376 except (TypeError, LookupError, AttributeError):
377 return self.undefined(obj=obj, name=attribute)
380 def parse(self, source, name=None, filename=None):
381 """Parse the sourcecode and return the abstract syntax tree. This
382 tree of nodes is used by the compiler to convert the template into
383 executable source- or bytecode. This is useful for debugging or to
384 extract information from templates.
386 If you are :ref:`developing Jinja2 extensions <writing-extensions>`
387 this gives you a good overview of the node tree generated.
390 return self._parse(source, name, filename)
391 except TemplateSyntaxError:
392 exc_info = sys.exc_info()
393 self.handle_exception(exc_info, source_hint=source)
395 def _parse(self, source, name, filename):
396 """Internal parsing function used by `parse` and `compile`."""
397 return Parser(self, source, name, _encode_filename(filename)).parse()
399 def lex(self, source, name=None, filename=None):
400 """Lex the given sourcecode and return a generator that yields
401 tokens as tuples in the form ``(lineno, token_type, value)``.
402 This can be useful for :ref:`extension development <writing-extensions>`
403 and debugging templates.
405 This does not perform preprocessing. If you want the preprocessing
406 of the extensions to be applied you have to filter source through
407 the :meth:`preprocess` method.
409 source = unicode(source)
411 return self.lexer.tokeniter(source, name, filename)
412 except TemplateSyntaxError:
413 exc_info = sys.exc_info()
414 self.handle_exception(exc_info, source_hint=source)
416 def preprocess(self, source, name=None, filename=None):
417 """Preprocesses the source with all extensions. This is automatically
418 called for all parsing and compiling methods but *not* for :meth:`lex`
419 because there you usually only want the actual source tokenized.
421 return reduce(lambda s, e: e.preprocess(s, name, filename),
422 self.iter_extensions(), unicode(source))
424 def _tokenize(self, source, name, filename=None, state=None):
425 """Called by the parser to do the preprocessing and filtering
426 for all the extensions. Returns a :class:`~jinja2.lexer.TokenStream`.
428 source = self.preprocess(source, name, filename)
429 stream = self.lexer.tokenize(source, name, filename, state)
430 for ext in self.iter_extensions():
431 stream = ext.filter_stream(stream)
432 if not isinstance(stream, TokenStream):
433 stream = TokenStream(stream, name, filename)
436 def _generate(self, source, name, filename, defer_init=False):
437 """Internal hook that can be overriden to hook a different generate
440 .. versionadded:: 2.5
442 return generate(source, self, name, filename, defer_init=defer_init)
444 def _compile(self, source, filename):
445 """Internal hook that can be overriden to hook a different compile
448 .. versionadded:: 2.5
450 return compile(source, filename, 'exec')
453 def compile(self, source, name=None, filename=None, raw=False,
455 """Compile a node or template source code. The `name` parameter is
456 the load name of the template after it was joined using
457 :meth:`join_path` if necessary, not the filename on the file system.
458 the `filename` parameter is the estimated filename of the template on
459 the file system. If the template came from a database or memory this
462 The return value of this method is a python code object. If the `raw`
463 parameter is `True` the return value will be a string with python
464 code equivalent to the bytecode returned otherwise. This method is
465 mainly used internally.
467 `defer_init` is use internally to aid the module code generator. This
468 causes the generated code to be able to import without the global
469 environment variable to be set.
471 .. versionadded:: 2.4
472 `defer_init` parameter added.
476 if isinstance(source, basestring):
478 source = self._parse(source, name, filename)
480 source = optimize(source, self)
481 source = self._generate(source, name, filename,
482 defer_init=defer_init)
486 filename = '<template>'
488 filename = _encode_filename(filename)
489 return self._compile(source, filename)
490 except TemplateSyntaxError:
491 exc_info = sys.exc_info()
492 self.handle_exception(exc_info, source_hint=source)
494 def compile_expression(self, source, undefined_to_none=True):
495 """A handy helper method that returns a callable that accepts keyword
496 arguments that appear as variables in the expression. If called it
497 returns the result of the expression.
499 This is useful if applications want to use the same rules as Jinja
500 in template "configuration files" or similar situations.
504 >>> env = Environment()
505 >>> expr = env.compile_expression('foo == 42')
511 Per default the return value is converted to `None` if the
512 expression returns an undefined value. This can be changed
513 by setting `undefined_to_none` to `False`.
515 >>> env.compile_expression('var')() is None
517 >>> env.compile_expression('var', undefined_to_none=False)()
520 .. versionadded:: 2.1
522 parser = Parser(self, source, state='variable')
525 expr = parser.parse_expression()
526 if not parser.stream.eos:
527 raise TemplateSyntaxError('chunk after expression',
528 parser.stream.current.lineno,
530 expr.set_environment(self)
531 except TemplateSyntaxError:
532 exc_info = sys.exc_info()
533 if exc_info is not None:
534 self.handle_exception(exc_info, source_hint=source)
535 body = [nodes.Assign(nodes.Name('result', 'store'), expr, lineno=1)]
536 template = self.from_string(nodes.Template(body, lineno=1))
537 return TemplateExpression(template, undefined_to_none)
539 def compile_templates(self, target, extensions=None, filter_func=None,
540 zip='deflated', log_function=None,
541 ignore_errors=True, py_compile=False):
542 """Compiles all the templates the loader can find, compiles them
543 and stores them in `target`. If `zip` is `None`, instead of in a
544 zipfile, the templates will be will be stored in a directory.
545 By default a deflate zip algorithm is used, to switch to
546 the stored algorithm, `zip` can be set to ``'stored'``.
548 `extensions` and `filter_func` are passed to :meth:`list_templates`.
549 Each template returned will be compiled to the target folder or
552 By default template compilation errors are ignored. In case a
553 log function is provided, errors are logged. If you want template
554 syntax errors to abort the compilation you can set `ignore_errors`
555 to `False` and you will get an exception on syntax errors.
557 If `py_compile` is set to `True` .pyc files will be written to the
558 target instead of standard .py files.
560 .. versionadded:: 2.4
562 from jinja2.loaders import ModuleLoader
564 if log_function is None:
565 log_function = lambda x: None
568 import imp, struct, marshal
569 py_header = imp.get_magic() + \
570 u'\xff\xff\xff\xff'.encode('iso-8859-15')
572 def write_file(filename, data, mode):
574 info = ZipInfo(filename)
575 info.external_attr = 0755 << 16L
576 zip_file.writestr(info, data)
578 f = open(os.path.join(target, filename), mode)
585 from zipfile import ZipFile, ZipInfo, ZIP_DEFLATED, ZIP_STORED
586 zip_file = ZipFile(target, 'w', dict(deflated=ZIP_DEFLATED,
587 stored=ZIP_STORED)[zip])
588 log_function('Compiling into Zip archive "%s"' % target)
590 if not os.path.isdir(target):
592 log_function('Compiling into folder "%s"' % target)
595 for name in self.list_templates(extensions, filter_func):
596 source, filename, _ = self.loader.get_source(self, name)
598 code = self.compile(source, name, filename, True, True)
599 except TemplateSyntaxError, e:
600 if not ignore_errors:
602 log_function('Could not compile "%s": %s' % (name, e))
605 filename = ModuleLoader.get_module_filename(name)
608 c = self._compile(code, _encode_filename(filename))
609 write_file(filename + 'c', py_header +
610 marshal.dumps(c), 'wb')
611 log_function('Byte-compiled "%s" as %s' %
612 (name, filename + 'c'))
614 write_file(filename, code, 'w')
615 log_function('Compiled "%s" as %s' % (name, filename))
620 log_function('Finished compiling templates')
622 def list_templates(self, extensions=None, filter_func=None):
623 """Returns a list of templates for this environment. This requires
624 that the loader supports the loader's
625 :meth:`~BaseLoader.list_templates` method.
627 If there are other files in the template folder besides the
628 actual templates, the returned list can be filtered. There are two
629 ways: either `extensions` is set to a list of file extensions for
630 templates, or a `filter_func` can be provided which is a callable that
631 is passed a template name and should return `True` if it should end up
634 If the loader does not support that, a :exc:`TypeError` is raised.
636 x = self.loader.list_templates()
637 if extensions is not None:
638 if filter_func is not None:
639 raise TypeError('either extensions or filter_func '
640 'can be passed, but not both')
641 filter_func = lambda x: '.' in x and \
642 x.rsplit('.', 1)[1] in extensions
643 if filter_func is not None:
644 x = filter(filter_func, x)
647 def handle_exception(self, exc_info=None, rendered=False, source_hint=None):
648 """Exception handling helper. This is used internally to either raise
649 rewritten exceptions or return a rendered traceback for the template.
651 global _make_traceback
653 exc_info = sys.exc_info()
655 # the debugging module is imported when it's used for the first time.
656 # we're doing a lot of stuff there and for applications that do not
657 # get any exceptions in template rendering there is no need to load
659 if _make_traceback is None:
660 from jinja2.debug import make_traceback as _make_traceback
661 traceback = _make_traceback(exc_info, source_hint)
662 if rendered and self.exception_formatter is not None:
663 return self.exception_formatter(traceback)
664 if self.exception_handler is not None:
665 self.exception_handler(traceback)
666 exc_type, exc_value, tb = traceback.standard_exc_info
667 raise exc_type, exc_value, tb
669 def join_path(self, template, parent):
670 """Join a template with the parent. By default all the lookups are
671 relative to the loader root so this method returns the `template`
672 parameter unchanged, but if the paths should be relative to the
673 parent template, this function can be used to calculate the real
676 Subclasses may override this method and implement template path
682 def _load_template(self, name, globals):
683 if self.loader is None:
684 raise TypeError('no loader for this environment specified')
685 if self.cache is not None:
686 template = self.cache.get(name)
687 if template is not None and (not self.auto_reload or \
688 template.is_up_to_date):
690 template = self.loader.load(self, name, globals)
691 if self.cache is not None:
692 self.cache[name] = template
696 def get_template(self, name, parent=None, globals=None):
697 """Load a template from the loader. If a loader is configured this
698 method ask the loader for the template and returns a :class:`Template`.
699 If the `parent` parameter is not `None`, :meth:`join_path` is called
700 to get the real template name before loading.
702 The `globals` parameter can be used to provide template wide globals.
703 These variables are available in the context at render time.
705 If the template does not exist a :exc:`TemplateNotFound` exception is
708 .. versionchanged:: 2.4
709 If `name` is a :class:`Template` object it is returned from the
712 if isinstance(name, Template):
714 if parent is not None:
715 name = self.join_path(name, parent)
716 return self._load_template(name, self.make_globals(globals))
719 def select_template(self, names, parent=None, globals=None):
720 """Works like :meth:`get_template` but tries a number of templates
721 before it fails. If it cannot find any of the templates, it will
722 raise a :exc:`TemplatesNotFound` exception.
724 .. versionadded:: 2.3
726 .. versionchanged:: 2.4
727 If `names` contains a :class:`Template` object it is returned
728 from the function unchanged.
731 raise TemplatesNotFound(message=u'Tried to select from an empty list '
733 globals = self.make_globals(globals)
735 if isinstance(name, Template):
737 if parent is not None:
738 name = self.join_path(name, parent)
740 return self._load_template(name, globals)
741 except TemplateNotFound:
743 raise TemplatesNotFound(names)
746 def get_or_select_template(self, template_name_or_list,
747 parent=None, globals=None):
748 """Does a typecheck and dispatches to :meth:`select_template`
749 if an iterable of template names is given, otherwise to
750 :meth:`get_template`.
752 .. versionadded:: 2.3
754 if isinstance(template_name_or_list, basestring):
755 return self.get_template(template_name_or_list, parent, globals)
756 elif isinstance(template_name_or_list, Template):
757 return template_name_or_list
758 return self.select_template(template_name_or_list, parent, globals)
760 def from_string(self, source, globals=None, template_class=None):
761 """Load a template from a string. This parses the source given and
762 returns a :class:`Template` object.
764 globals = self.make_globals(globals)
765 cls = template_class or self.template_class
766 return cls.from_code(self, self.compile(source), globals, None)
768 def make_globals(self, d):
769 """Return a dict for the globals."""
772 return dict(self.globals, **d)
775 class Template(object):
776 """The central template object. This class represents a compiled template
777 and is used to evaluate it.
779 Normally the template object is generated from an :class:`Environment` but
780 it also has a constructor that makes it possible to create a template
781 instance directly using the constructor. It takes the same arguments as
782 the environment constructor but it's not possible to specify a loader.
784 Every template object has a few methods and members that are guaranteed
785 to exist. However it's important that a template object should be
786 considered immutable. Modifications on the object are not supported.
788 Template objects created from the constructor rather than an environment
789 do have an `environment` attribute that points to a temporary environment
790 that is probably shared with other templates created with the constructor
791 and compatible settings.
793 >>> template = Template('Hello {{ name }}!')
794 >>> template.render(name='John Doe')
797 >>> stream = template.stream(name='John Doe')
801 Traceback (most recent call last):
806 def __new__(cls, source,
807 block_start_string=BLOCK_START_STRING,
808 block_end_string=BLOCK_END_STRING,
809 variable_start_string=VARIABLE_START_STRING,
810 variable_end_string=VARIABLE_END_STRING,
811 comment_start_string=COMMENT_START_STRING,
812 comment_end_string=COMMENT_END_STRING,
813 line_statement_prefix=LINE_STATEMENT_PREFIX,
814 line_comment_prefix=LINE_COMMENT_PREFIX,
815 trim_blocks=TRIM_BLOCKS,
816 newline_sequence=NEWLINE_SEQUENCE,
822 env = get_spontaneous_environment(
823 block_start_string, block_end_string, variable_start_string,
824 variable_end_string, comment_start_string, comment_end_string,
825 line_statement_prefix, line_comment_prefix, trim_blocks,
826 newline_sequence, frozenset(extensions), optimized, undefined,
827 finalize, autoescape, None, 0, False, None)
828 return env.from_string(source, template_class=cls)
831 def from_code(cls, environment, code, globals, uptodate=None):
832 """Creates a template object from compiled code and the globals. This
833 is used by the loaders and environment to create a template object.
836 'environment': environment,
837 '__file__': code.co_filename
839 exec code in namespace
840 rv = cls._from_namespace(environment, namespace, globals)
841 rv._uptodate = uptodate
845 def from_module_dict(cls, environment, module_dict, globals):
846 """Creates a template object from a module. This is used by the
847 module loader to create a template object.
849 .. versionadded:: 2.4
851 return cls._from_namespace(environment, module_dict, globals)
854 def _from_namespace(cls, environment, namespace, globals):
855 t = object.__new__(cls)
856 t.environment = environment
858 t.name = namespace['name']
859 t.filename = namespace['__file__']
860 t.blocks = namespace['blocks']
862 # render function and module
863 t.root_render_func = namespace['root']
866 # debug and loader helpers
867 t._debug_info = namespace['debug_info']
870 # store the reference
871 namespace['environment'] = environment
872 namespace['__jinja_template__'] = t
876 def render(self, *args, **kwargs):
877 """This method accepts the same arguments as the `dict` constructor:
878 A dict, a dict subclass or some keyword arguments. If no arguments
879 are given the context will be empty. These two calls do the same::
881 template.render(knights='that say nih')
882 template.render({'knights': 'that say nih'})
884 This will return the rendered template as unicode string.
886 vars = dict(*args, **kwargs)
888 return concat(self.root_render_func(self.new_context(vars)))
890 exc_info = sys.exc_info()
891 return self.environment.handle_exception(exc_info, True)
893 def stream(self, *args, **kwargs):
894 """Works exactly like :meth:`generate` but returns a
895 :class:`TemplateStream`.
897 return TemplateStream(self.generate(*args, **kwargs))
899 def generate(self, *args, **kwargs):
900 """For very large templates it can be useful to not render the whole
901 template at once but evaluate each statement after another and yield
902 piece for piece. This method basically does exactly that and returns
903 a generator that yields one item after another as unicode strings.
905 It accepts the same arguments as :meth:`render`.
907 vars = dict(*args, **kwargs)
909 for event in self.root_render_func(self.new_context(vars)):
912 exc_info = sys.exc_info()
915 yield self.environment.handle_exception(exc_info, True)
917 def new_context(self, vars=None, shared=False, locals=None):
918 """Create a new :class:`Context` for this template. The vars
919 provided will be passed to the template. Per default the globals
920 are added to the context. If shared is set to `True` the data
921 is passed as it to the context without adding the globals.
923 `locals` can be a dict of local variables for internal usage.
925 return new_context(self.environment, self.name, self.blocks,
926 vars, shared, self.globals, locals)
928 def make_module(self, vars=None, shared=False, locals=None):
929 """This method works like the :attr:`module` attribute when called
930 without arguments but it will evaluate the template on every call
931 rather than caching it. It's also possible to provide
932 a dict which is then used as context. The arguments are the same
933 as for the :meth:`new_context` method.
935 return TemplateModule(self, self.new_context(vars, shared, locals))
939 """The template as module. This is used for imports in the
940 template runtime but is also useful if one wants to access
941 exported template variables from the Python layer:
943 >>> t = Template('{% macro foo() %}42{% endmacro %}23')
944 >>> unicode(t.module)
949 if self._module is not None:
951 self._module = rv = self.make_module()
954 def get_corresponding_lineno(self, lineno):
955 """Return the source line number of a line number in the
956 generated bytecode as they are not in sync.
958 for template_line, code_line in reversed(self.debug_info):
959 if code_line <= lineno:
964 def is_up_to_date(self):
965 """If this variable is `False` there is a newer version available."""
966 if self._uptodate is None:
968 return self._uptodate()
971 def debug_info(self):
972 """The debug info mapping."""
973 return [tuple(map(int, x.split('='))) for x in
974 self._debug_info.split('&')]
977 if self.name is None:
978 name = 'memory:%x' % id(self)
980 name = repr(self.name)
981 return '<%s %s>' % (self.__class__.__name__, name)
984 class TemplateModule(object):
985 """Represents an imported template. All the exported names of the
986 template are available as attributes on this object. Additionally
987 converting it into an unicode- or bytestrings renders the contents.
990 def __init__(self, template, context):
991 self._body_stream = list(template.root_render_func(context))
992 self.__dict__.update(context.get_exported())
993 self.__name__ = template.name
996 return Markup(concat(self._body_stream))
999 return unicode(self).encode('utf-8')
1001 # unicode goes after __str__ because we configured 2to3 to rename
1002 # __unicode__ to __str__. because the 2to3 tree is not designed to
1003 # remove nodes from it, we leave the above __str__ around and let
1004 # it override at runtime.
1005 def __unicode__(self):
1006 return concat(self._body_stream)
1009 if self.__name__ is None:
1010 name = 'memory:%x' % id(self)
1012 name = repr(self.__name__)
1013 return '<%s %s>' % (self.__class__.__name__, name)
1016 class TemplateExpression(object):
1017 """The :meth:`jinja2.Environment.compile_expression` method returns an
1018 instance of this object. It encapsulates the expression-like access
1019 to the template with an expression it wraps.
1022 def __init__(self, template, undefined_to_none):
1023 self._template = template
1024 self._undefined_to_none = undefined_to_none
1026 def __call__(self, *args, **kwargs):
1027 context = self._template.new_context(dict(*args, **kwargs))
1028 consume(self._template.root_render_func(context))
1029 rv = context.vars['result']
1030 if self._undefined_to_none and isinstance(rv, Undefined):
1035 class TemplateStream(object):
1036 """A template stream works pretty much like an ordinary python generator
1037 but it can buffer multiple items to reduce the number of total iterations.
1038 Per default the output is unbuffered which means that for every unbuffered
1039 instruction in the template one unicode string is yielded.
1041 If buffering is enabled with a buffer size of 5, five items are combined
1042 into a new unicode string. This is mainly useful if you are streaming
1043 big templates to a client via WSGI which flushes after each iteration.
1046 def __init__(self, gen):
1048 self.disable_buffering()
1050 def dump(self, fp, encoding=None, errors='strict'):
1051 """Dump the complete stream into a file or file-like object.
1052 Per default unicode strings are written, if you want to encode
1053 before writing specifiy an `encoding`.
1057 Template('Hello {{ name }}!').stream(name='foo').dump('hello.html')
1060 if isinstance(fp, basestring):
1064 if encoding is not None:
1065 iterable = (x.encode(encoding, errors) for x in self)
1068 if hasattr(fp, 'writelines'):
1069 fp.writelines(iterable)
1071 for item in iterable:
1077 def disable_buffering(self):
1078 """Disable the output buffering."""
1079 self._next = self._gen.next
1080 self.buffered = False
1082 def enable_buffering(self, size=5):
1083 """Enable buffering. Buffer `size` items before yielding them."""
1085 raise ValueError('buffer size too small')
1087 def generator(next):
1094 while c_size < size:
1099 except StopIteration:
1106 self.buffered = True
1107 self._next = generator(self._gen.next).next
1116 # hook in default template class. if anyone reads this comment: ignore that
1117 # it's possible to use custom templates ;-)
1118 Environment.template_class = Template