/python/lib/Lib/site-packages/django/template/base.py
Python | 1019 lines | 973 code | 29 blank | 17 comment | 27 complexity | 5366b7941915f04b72078dc3354d5de5 MD5 | raw file
Possible License(s): BSD-3-Clause, Apache-2.0, MPL-2.0-no-copyleft-exception, MIT, EPL-1.0, AGPL-1.0
- import imp
- import re
- from inspect import getargspec
- from django.conf import settings
- from django.template.context import Context, RequestContext, ContextPopException
- from django.utils.importlib import import_module
- from django.utils.itercompat import is_iterable
- from django.utils.functional import curry, Promise
- from django.utils.text import smart_split, unescape_string_literal, get_text_list
- from django.utils.encoding import smart_unicode, force_unicode, smart_str
- from django.utils.translation import ugettext as _
- from django.utils.safestring import SafeData, EscapeData, mark_safe, mark_for_escaping
- from django.utils.formats import localize
- from django.utils.html import escape
- from django.utils.module_loading import module_has_submodule
- TOKEN_TEXT = 0
- TOKEN_VAR = 1
- TOKEN_BLOCK = 2
- TOKEN_COMMENT = 3
- # template syntax constants
- FILTER_SEPARATOR = '|'
- FILTER_ARGUMENT_SEPARATOR = ':'
- VARIABLE_ATTRIBUTE_SEPARATOR = '.'
- BLOCK_TAG_START = '{%'
- BLOCK_TAG_END = '%}'
- VARIABLE_TAG_START = '{{'
- VARIABLE_TAG_END = '}}'
- COMMENT_TAG_START = '{#'
- COMMENT_TAG_END = '#}'
- TRANSLATOR_COMMENT_MARK = 'Translators'
- SINGLE_BRACE_START = '{'
- SINGLE_BRACE_END = '}'
- ALLOWED_VARIABLE_CHARS = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_.'
- # what to report as the origin for templates that come from non-loader sources
- # (e.g. strings)
- UNKNOWN_SOURCE = '<unknown source>'
- # match a variable or block tag and capture the entire tag, including start/end delimiters
- tag_re = re.compile('(%s.*?%s|%s.*?%s|%s.*?%s)' % (re.escape(BLOCK_TAG_START), re.escape(BLOCK_TAG_END),
- re.escape(VARIABLE_TAG_START), re.escape(VARIABLE_TAG_END),
- re.escape(COMMENT_TAG_START), re.escape(COMMENT_TAG_END)))
- # global dictionary of libraries that have been loaded using get_library
- libraries = {}
- # global list of libraries to load by default for a new parser
- builtins = []
- # True if TEMPLATE_STRING_IF_INVALID contains a format string (%s). None means
- # uninitialised.
- invalid_var_format_string = None
- class TemplateSyntaxError(Exception):
- pass
- class TemplateDoesNotExist(Exception):
- pass
- class TemplateEncodingError(Exception):
- pass
- class VariableDoesNotExist(Exception):
- def __init__(self, msg, params=()):
- self.msg = msg
- self.params = params
- def __str__(self):
- return unicode(self).encode('utf-8')
- def __unicode__(self):
- return self.msg % tuple([force_unicode(p, errors='replace') for p in self.params])
- class InvalidTemplateLibrary(Exception):
- pass
- class Origin(object):
- def __init__(self, name):
- self.name = name
- def reload(self):
- raise NotImplementedError
- def __str__(self):
- return self.name
- class StringOrigin(Origin):
- def __init__(self, source):
- super(StringOrigin, self).__init__(UNKNOWN_SOURCE)
- self.source = source
- def reload(self):
- return self.source
- class Template(object):
- def __init__(self, template_string, origin=None, name='<Unknown Template>'):
- try:
- template_string = smart_unicode(template_string)
- except UnicodeDecodeError:
- raise TemplateEncodingError("Templates can only be constructed from unicode or UTF-8 strings.")
- if settings.TEMPLATE_DEBUG and origin is None:
- origin = StringOrigin(template_string)
- self.nodelist = compile_string(template_string, origin)
- self.name = name
- def __iter__(self):
- for node in self.nodelist:
- for subnode in node:
- yield subnode
- def _render(self, context):
- return self.nodelist.render(context)
- def render(self, context):
- "Display stage -- can be called many times"
- context.render_context.push()
- try:
- return self._render(context)
- finally:
- context.render_context.pop()
- def compile_string(template_string, origin):
- "Compiles template_string into NodeList ready for rendering"
- if settings.TEMPLATE_DEBUG:
- from debug import DebugLexer, DebugParser
- lexer_class, parser_class = DebugLexer, DebugParser
- else:
- lexer_class, parser_class = Lexer, Parser
- lexer = lexer_class(template_string, origin)
- parser = parser_class(lexer.tokenize())
- return parser.parse()
- class Token(object):
- def __init__(self, token_type, contents):
- # token_type must be TOKEN_TEXT, TOKEN_VAR, TOKEN_BLOCK or TOKEN_COMMENT.
- self.token_type, self.contents = token_type, contents
- self.lineno = None
- def __str__(self):
- return '<%s token: "%s...">' % \
- ({TOKEN_TEXT: 'Text', TOKEN_VAR: 'Var', TOKEN_BLOCK: 'Block', TOKEN_COMMENT: 'Comment'}[self.token_type],
- self.contents[:20].replace('\n', ''))
- def split_contents(self):
- split = []
- bits = iter(smart_split(self.contents))
- for bit in bits:
- # Handle translation-marked template pieces
- if bit.startswith('_("') or bit.startswith("_('"):
- sentinal = bit[2] + ')'
- trans_bit = [bit]
- while not bit.endswith(sentinal):
- bit = bits.next()
- trans_bit.append(bit)
- bit = ' '.join(trans_bit)
- split.append(bit)
- return split
- class Lexer(object):
- def __init__(self, template_string, origin):
- self.template_string = template_string
- self.origin = origin
- self.lineno = 1
- def tokenize(self):
- "Return a list of tokens from a given template_string."
- in_tag = False
- result = []
- for bit in tag_re.split(self.template_string):
- if bit:
- result.append(self.create_token(bit, in_tag))
- in_tag = not in_tag
- return result
- def create_token(self, token_string, in_tag):
- """
- Convert the given token string into a new Token object and return it.
- If in_tag is True, we are processing something that matched a tag,
- otherwise it should be treated as a literal string.
- """
- if in_tag:
- if token_string.startswith(VARIABLE_TAG_START):
- token = Token(TOKEN_VAR, token_string[len(VARIABLE_TAG_START):-len(VARIABLE_TAG_END)].strip())
- elif token_string.startswith(BLOCK_TAG_START):
- token = Token(TOKEN_BLOCK, token_string[len(BLOCK_TAG_START):-len(BLOCK_TAG_END)].strip())
- elif token_string.startswith(COMMENT_TAG_START):
- content = ''
- if token_string.find(TRANSLATOR_COMMENT_MARK):
- content = token_string[len(COMMENT_TAG_START):-len(COMMENT_TAG_END)].strip()
- token = Token(TOKEN_COMMENT, content)
- else:
- token = Token(TOKEN_TEXT, token_string)
- token.lineno = self.lineno
- self.lineno += token_string.count('\n')
- return token
- class Parser(object):
- def __init__(self, tokens):
- self.tokens = tokens
- self.tags = {}
- self.filters = {}
- for lib in builtins:
- self.add_library(lib)
- def parse(self, parse_until=None):
- if parse_until is None: parse_until = []
- nodelist = self.create_nodelist()
- while self.tokens:
- token = self.next_token()
- if token.token_type == TOKEN_TEXT:
- self.extend_nodelist(nodelist, TextNode(token.contents), token)
- elif token.token_type == TOKEN_VAR:
- if not token.contents:
- self.empty_variable(token)
- filter_expression = self.compile_filter(token.contents)
- var_node = self.create_variable_node(filter_expression)
- self.extend_nodelist(nodelist, var_node,token)
- elif token.token_type == TOKEN_BLOCK:
- if token.contents in parse_until:
- # put token back on token list so calling code knows why it terminated
- self.prepend_token(token)
- return nodelist
- try:
- command = token.contents.split()[0]
- except IndexError:
- self.empty_block_tag(token)
- # execute callback function for this tag and append resulting node
- self.enter_command(command, token)
- try:
- compile_func = self.tags[command]
- except KeyError:
- self.invalid_block_tag(token, command, parse_until)
- try:
- compiled_result = compile_func(self, token)
- except TemplateSyntaxError, e:
- if not self.compile_function_error(token, e):
- raise
- self.extend_nodelist(nodelist, compiled_result, token)
- self.exit_command()
- if parse_until:
- self.unclosed_block_tag(parse_until)
- return nodelist
- def skip_past(self, endtag):
- while self.tokens:
- token = self.next_token()
- if token.token_type == TOKEN_BLOCK and token.contents == endtag:
- return
- self.unclosed_block_tag([endtag])
- def create_variable_node(self, filter_expression):
- return VariableNode(filter_expression)
- def create_nodelist(self):
- return NodeList()
- def extend_nodelist(self, nodelist, node, token):
- if node.must_be_first and nodelist:
- try:
- if nodelist.contains_nontext:
- raise AttributeError
- except AttributeError:
- raise TemplateSyntaxError("%r must be the first tag in the template." % node)
- if isinstance(nodelist, NodeList) and not isinstance(node, TextNode):
- nodelist.contains_nontext = True
- nodelist.append(node)
- def enter_command(self, command, token):
- pass
- def exit_command(self):
- pass
- def error(self, token, msg):
- return TemplateSyntaxError(msg)
- def empty_variable(self, token):
- raise self.error(token, "Empty variable tag")
- def empty_block_tag(self, token):
- raise self.error(token, "Empty block tag")
- def invalid_block_tag(self, token, command, parse_until=None):
- if parse_until:
- raise self.error(token, "Invalid block tag: '%s', expected %s" % (command, get_text_list(["'%s'" % p for p in parse_until])))
- raise self.error(token, "Invalid block tag: '%s'" % command)
- def unclosed_block_tag(self, parse_until):
- raise self.error(None, "Unclosed tags: %s " % ', '.join(parse_until))
- def compile_function_error(self, token, e):
- pass
- def next_token(self):
- return self.tokens.pop(0)
- def prepend_token(self, token):
- self.tokens.insert(0, token)
- def delete_first_token(self):
- del self.tokens[0]
- def add_library(self, lib):
- self.tags.update(lib.tags)
- self.filters.update(lib.filters)
- def compile_filter(self, token):
- "Convenient wrapper for FilterExpression"
- return FilterExpression(token, self)
- def find_filter(self, filter_name):
- if filter_name in self.filters:
- return self.filters[filter_name]
- else:
- raise TemplateSyntaxError("Invalid filter: '%s'" % filter_name)
- class TokenParser(object):
- """
- Subclass this and implement the top() method to parse a template line. When
- instantiating the parser, pass in the line from the Django template parser.
- The parser's "tagname" instance-variable stores the name of the tag that
- the filter was called with.
- """
- def __init__(self, subject):
- self.subject = subject
- self.pointer = 0
- self.backout = []
- self.tagname = self.tag()
- def top(self):
- "Overload this method to do the actual parsing and return the result."
- raise NotImplementedError()
- def more(self):
- "Returns True if there is more stuff in the tag."
- return self.pointer < len(self.subject)
- def back(self):
- "Undoes the last microparser. Use this for lookahead and backtracking."
- if not len(self.backout):
- raise TemplateSyntaxError("back called without some previous parsing")
- self.pointer = self.backout.pop()
- def tag(self):
- "A microparser that just returns the next tag from the line."
- subject = self.subject
- i = self.pointer
- if i >= len(subject):
- raise TemplateSyntaxError("expected another tag, found end of string: %s" % subject)
- p = i
- while i < len(subject) and subject[i] not in (' ', '\t'):
- i += 1
- s = subject[p:i]
- while i < len(subject) and subject[i] in (' ', '\t'):
- i += 1
- self.backout.append(self.pointer)
- self.pointer = i
- return s
- def value(self):
- "A microparser that parses for a value: some string constant or variable name."
- subject = self.subject
- i = self.pointer
- def next_space_index(subject, i):
- "Increment pointer until a real space (i.e. a space not within quotes) is encountered"
- while i < len(subject) and subject[i] not in (' ', '\t'):
- if subject[i] in ('"', "'"):
- c = subject[i]
- i += 1
- while i < len(subject) and subject[i] != c:
- i += 1
- if i >= len(subject):
- raise TemplateSyntaxError("Searching for value. Unexpected end of string in column %d: %s" % (i, subject))
- i += 1
- return i
- if i >= len(subject):
- raise TemplateSyntaxError("Searching for value. Expected another value but found end of string: %s" % subject)
- if subject[i] in ('"', "'"):
- p = i
- i += 1
- while i < len(subject) and subject[i] != subject[p]:
- i += 1
- if i >= len(subject):
- raise TemplateSyntaxError("Searching for value. Unexpected end of string in column %d: %s" % (i, subject))
- i += 1
- # Continue parsing until next "real" space, so that filters are also included
- i = next_space_index(subject, i)
- res = subject[p:i]
- while i < len(subject) and subject[i] in (' ', '\t'):
- i += 1
- self.backout.append(self.pointer)
- self.pointer = i
- return res
- else:
- p = i
- i = next_space_index(subject, i)
- s = subject[p:i]
- while i < len(subject) and subject[i] in (' ', '\t'):
- i += 1
- self.backout.append(self.pointer)
- self.pointer = i
- return s
- # This only matches constant *strings* (things in quotes or marked for
- # translation). Numbers are treated as variables for implementation reasons
- # (so that they retain their type when passed to filters).
- constant_string = r"""
- (?:%(i18n_open)s%(strdq)s%(i18n_close)s|
- %(i18n_open)s%(strsq)s%(i18n_close)s|
- %(strdq)s|
- %(strsq)s)
- """ % {
- 'strdq': r'"[^"\\]*(?:\\.[^"\\]*)*"', # double-quoted string
- 'strsq': r"'[^'\\]*(?:\\.[^'\\]*)*'", # single-quoted string
- 'i18n_open' : re.escape("_("),
- 'i18n_close' : re.escape(")"),
- }
- constant_string = constant_string.replace("\n", "")
- filter_raw_string = r"""
- ^(?P<constant>%(constant)s)|
- ^(?P<var>[%(var_chars)s]+|%(num)s)|
- (?:%(filter_sep)s
- (?P<filter_name>\w+)
- (?:%(arg_sep)s
- (?:
- (?P<constant_arg>%(constant)s)|
- (?P<var_arg>[%(var_chars)s]+|%(num)s)
- )
- )?
- )""" % {
- 'constant': constant_string,
- 'num': r'[-+\.]?\d[\d\.e]*',
- 'var_chars': "\w\." ,
- 'filter_sep': re.escape(FILTER_SEPARATOR),
- 'arg_sep': re.escape(FILTER_ARGUMENT_SEPARATOR),
- }
- filter_re = re.compile(filter_raw_string, re.UNICODE|re.VERBOSE)
- class FilterExpression(object):
- r"""
- Parses a variable token and its optional filters (all as a single string),
- and return a list of tuples of the filter name and arguments.
- Sample:
- >>> token = 'variable|default:"Default value"|date:"Y-m-d"'
- >>> p = Parser('')
- >>> fe = FilterExpression(token, p)
- >>> len(fe.filters)
- 2
- >>> fe.var
- <Variable: 'variable'>
- This class should never be instantiated outside of the
- get_filters_from_token helper function.
- """
- def __init__(self, token, parser):
- self.token = token
- matches = filter_re.finditer(token)
- var_obj = None
- filters = []
- upto = 0
- for match in matches:
- start = match.start()
- if upto != start:
- raise TemplateSyntaxError("Could not parse some characters: %s|%s|%s" % \
- (token[:upto], token[upto:start], token[start:]))
- if var_obj is None:
- var, constant = match.group("var", "constant")
- if constant:
- try:
- var_obj = Variable(constant).resolve({})
- except VariableDoesNotExist:
- var_obj = None
- elif var is None:
- raise TemplateSyntaxError("Could not find variable at start of %s." % token)
- else:
- var_obj = Variable(var)
- else:
- filter_name = match.group("filter_name")
- args = []
- constant_arg, var_arg = match.group("constant_arg", "var_arg")
- if constant_arg:
- args.append((False, Variable(constant_arg).resolve({})))
- elif var_arg:
- args.append((True, Variable(var_arg)))
- filter_func = parser.find_filter(filter_name)
- self.args_check(filter_name, filter_func, args)
- filters.append((filter_func, args))
- upto = match.end()
- if upto != len(token):
- raise TemplateSyntaxError("Could not parse the remainder: '%s' from '%s'" % (token[upto:], token))
- self.filters = filters
- self.var = var_obj
- def resolve(self, context, ignore_failures=False):
- if isinstance(self.var, Variable):
- try:
- obj = self.var.resolve(context)
- except VariableDoesNotExist:
- if ignore_failures:
- obj = None
- else:
- if settings.TEMPLATE_STRING_IF_INVALID:
- global invalid_var_format_string
- if invalid_var_format_string is None:
- invalid_var_format_string = '%s' in settings.TEMPLATE_STRING_IF_INVALID
- if invalid_var_format_string:
- return settings.TEMPLATE_STRING_IF_INVALID % self.var
- return settings.TEMPLATE_STRING_IF_INVALID
- else:
- obj = settings.TEMPLATE_STRING_IF_INVALID
- else:
- obj = self.var
- for func, args in self.filters:
- arg_vals = []
- for lookup, arg in args:
- if not lookup:
- arg_vals.append(mark_safe(arg))
- else:
- arg_vals.append(arg.resolve(context))
- if getattr(func, 'needs_autoescape', False):
- new_obj = func(obj, autoescape=context.autoescape, *arg_vals)
- else:
- new_obj = func(obj, *arg_vals)
- if getattr(func, 'is_safe', False) and isinstance(obj, SafeData):
- obj = mark_safe(new_obj)
- elif isinstance(obj, EscapeData):
- obj = mark_for_escaping(new_obj)
- else:
- obj = new_obj
- return obj
- def args_check(name, func, provided):
- provided = list(provided)
- plen = len(provided)
- # Check to see if a decorator is providing the real function.
- func = getattr(func, '_decorated_function', func)
- args, varargs, varkw, defaults = getargspec(func)
- # First argument is filter input.
- args.pop(0)
- if defaults:
- nondefs = args[:-len(defaults)]
- else:
- nondefs = args
- # Args without defaults must be provided.
- try:
- for arg in nondefs:
- provided.pop(0)
- except IndexError:
- # Not enough
- raise TemplateSyntaxError("%s requires %d arguments, %d provided" % (name, len(nondefs), plen))
- # Defaults can be overridden.
- defaults = defaults and list(defaults) or []
- try:
- for parg in provided:
- defaults.pop(0)
- except IndexError:
- # Too many.
- raise TemplateSyntaxError("%s requires %d arguments, %d provided" % (name, len(nondefs), plen))
- return True
- args_check = staticmethod(args_check)
- def __str__(self):
- return self.token
- def resolve_variable(path, context):
- """
- Returns the resolved variable, which may contain attribute syntax, within
- the given context.
- Deprecated; use the Variable class instead.
- """
- return Variable(path).resolve(context)
- class Variable(object):
- r"""
- A template variable, resolvable against a given context. The variable may be
- a hard-coded string (if it begins and ends with single or double quote
- marks)::
- >>> c = {'article': {'section':u'News'}}
- >>> Variable('article.section').resolve(c)
- u'News'
- >>> Variable('article').resolve(c)
- {'section': u'News'}
- >>> class AClass: pass
- >>> c = AClass()
- >>> c.article = AClass()
- >>> c.article.section = u'News'
- (The example assumes VARIABLE_ATTRIBUTE_SEPARATOR is '.')
- """
- def __init__(self, var):
- self.var = var
- self.literal = None
- self.lookups = None
- self.translate = False
- try:
- # First try to treat this variable as a number.
- #
- # Note that this could cause an OverflowError here that we're not
- # catching. Since this should only happen at compile time, that's
- # probably OK.
- self.literal = float(var)
- # So it's a float... is it an int? If the original value contained a
- # dot or an "e" then it was a float, not an int.
- if '.' not in var and 'e' not in var.lower():
- self.literal = int(self.literal)
- # "2." is invalid
- if var.endswith('.'):
- raise ValueError
- except ValueError:
- # A ValueError means that the variable isn't a number.
- if var.startswith('_(') and var.endswith(')'):
- # The result of the lookup should be translated at rendering
- # time.
- self.translate = True
- var = var[2:-1]
- # If it's wrapped with quotes (single or double), then
- # we're also dealing with a literal.
- try:
- self.literal = mark_safe(unescape_string_literal(var))
- except ValueError:
- # Otherwise we'll set self.lookups so that resolve() knows we're
- # dealing with a bonafide variable
- if var.find(VARIABLE_ATTRIBUTE_SEPARATOR + '_') > -1 or var[0] == '_':
- raise TemplateSyntaxError("Variables and attributes may not begin with underscores: '%s'" % var)
- self.lookups = tuple(var.split(VARIABLE_ATTRIBUTE_SEPARATOR))
- def resolve(self, context):
- """Resolve this variable against a given context."""
- if self.lookups is not None:
- # We're dealing with a variable that needs to be resolved
- value = self._resolve_lookup(context)
- else:
- # We're dealing with a literal, so it's already been "resolved"
- value = self.literal
- if self.translate:
- return _(value)
- return value
- def __repr__(self):
- return "<%s: %r>" % (self.__class__.__name__, self.var)
- def __str__(self):
- return self.var
- def _resolve_lookup(self, context):
- """
- Performs resolution of a real variable (i.e. not a literal) against the
- given context.
- As indicated by the method's name, this method is an implementation
- detail and shouldn't be called by external code. Use Variable.resolve()
- instead.
- """
- current = context
- try: # catch-all for silent variable failures
- for bit in self.lookups:
- try: # dictionary lookup
- current = current[bit]
- except (TypeError, AttributeError, KeyError):
- try: # attribute lookup
- current = getattr(current, bit)
- except (TypeError, AttributeError):
- try: # list-index lookup
- current = current[int(bit)]
- except (IndexError, # list index out of range
- ValueError, # invalid literal for int()
- KeyError, # current is a dict without `int(bit)` key
- TypeError, # unsubscriptable object
- ):
- raise VariableDoesNotExist("Failed lookup for key [%s] in %r", (bit, current)) # missing attribute
- if callable(current):
- if getattr(current, 'alters_data', False):
- current = settings.TEMPLATE_STRING_IF_INVALID
- else:
- try: # method call (assuming no args required)
- current = current()
- except TypeError: # arguments *were* required
- # GOTCHA: This will also catch any TypeError
- # raised in the function itself.
- current = settings.TEMPLATE_STRING_IF_INVALID # invalid method call
- except Exception, e:
- if getattr(e, 'silent_variable_failure', False):
- current = settings.TEMPLATE_STRING_IF_INVALID
- else:
- raise
- return current
- class Node(object):
- # Set this to True for nodes that must be first in the template (although
- # they can be preceded by text nodes.
- must_be_first = False
- child_nodelists = ('nodelist',)
- def render(self, context):
- "Return the node rendered as a string"
- pass
- def __iter__(self):
- yield self
- def get_nodes_by_type(self, nodetype):
- "Return a list of all nodes (within this node and its nodelist) of the given type"
- nodes = []
- if isinstance(self, nodetype):
- nodes.append(self)
- for attr in self.child_nodelists:
- nodelist = getattr(self, attr, None)
- if nodelist:
- nodes.extend(nodelist.get_nodes_by_type(nodetype))
- return nodes
- class NodeList(list):
- # Set to True the first time a non-TextNode is inserted by
- # extend_nodelist().
- contains_nontext = False
- def render(self, context):
- bits = []
- for node in self:
- if isinstance(node, Node):
- bits.append(self.render_node(node, context))
- else:
- bits.append(node)
- return mark_safe(''.join([force_unicode(b) for b in bits]))
- def get_nodes_by_type(self, nodetype):
- "Return a list of all nodes of the given type"
- nodes = []
- for node in self:
- nodes.extend(node.get_nodes_by_type(nodetype))
- return nodes
- def render_node(self, node, context):
- return node.render(context)
- class TextNode(Node):
- def __init__(self, s):
- self.s = s
- def __repr__(self):
- return "<Text Node: '%s'>" % smart_str(self.s[:25], 'ascii',
- errors='replace')
- def render(self, context):
- return self.s
- def _render_value_in_context(value, context):
- """
- Converts any value to a string to become part of a rendered template. This
- means escaping, if required, and conversion to a unicode object. If value
- is a string, it is expected to have already been translated.
- """
- value = localize(value, use_l10n=context.use_l10n)
- value = force_unicode(value)
- if (context.autoescape and not isinstance(value, SafeData)) or isinstance(value, EscapeData):
- return escape(value)
- else:
- return value
- class VariableNode(Node):
- def __init__(self, filter_expression):
- self.filter_expression = filter_expression
- def __repr__(self):
- return "<Variable Node: %s>" % self.filter_expression
- def render(self, context):
- try:
- output = self.filter_expression.resolve(context)
- except UnicodeDecodeError:
- # Unicode conversion can fail sometimes for reasons out of our
- # control (e.g. exception rendering). In that case, we fail quietly.
- return ''
- return _render_value_in_context(output, context)
- def generic_tag_compiler(params, defaults, name, node_class, parser, token):
- "Returns a template.Node subclass."
- bits = token.split_contents()[1:]
- bmax = len(params)
- def_len = defaults and len(defaults) or 0
- bmin = bmax - def_len
- if(len(bits) < bmin or len(bits) > bmax):
- if bmin == bmax:
- message = "%s takes %s arguments" % (name, bmin)
- else:
- message = "%s takes between %s and %s arguments" % (name, bmin, bmax)
- raise TemplateSyntaxError(message)
- return node_class(bits)
- class Library(object):
- def __init__(self):
- self.filters = {}
- self.tags = {}
- def tag(self, name=None, compile_function=None):
- if name == None and compile_function == None:
- # @register.tag()
- return self.tag_function
- elif name != None and compile_function == None:
- if(callable(name)):
- # @register.tag
- return self.tag_function(name)
- else:
- # @register.tag('somename') or @register.tag(name='somename')
- def dec(func):
- return self.tag(name, func)
- return dec
- elif name != None and compile_function != None:
- # register.tag('somename', somefunc)
- self.tags[name] = compile_function
- return compile_function
- else:
- raise InvalidTemplateLibrary("Unsupported arguments to Library.tag: (%r, %r)", (name, compile_function))
- def tag_function(self,func):
- self.tags[getattr(func, "_decorated_function", func).__name__] = func
- return func
- def filter(self, name=None, filter_func=None):
- if name == None and filter_func == None:
- # @register.filter()
- return self.filter_function
- elif filter_func == None:
- if(callable(name)):
- # @register.filter
- return self.filter_function(name)
- else:
- # @register.filter('somename') or @register.filter(name='somename')
- def dec(func):
- return self.filter(name, func)
- return dec
- elif name != None and filter_func != None:
- # register.filter('somename', somefunc)
- self.filters[name] = filter_func
- return filter_func
- else:
- raise InvalidTemplateLibrary("Unsupported arguments to Library.filter: (%r, %r)", (name, filter_func))
- def filter_function(self, func):
- self.filters[getattr(func, "_decorated_function", func).__name__] = func
- return func
- def simple_tag(self, func=None, takes_context=None):
- def dec(func):
- params, xx, xxx, defaults = getargspec(func)
- if takes_context:
- if params[0] == 'context':
- params = params[1:]
- else:
- raise TemplateSyntaxError("Any tag function decorated with takes_context=True must have a first argument of 'context'")
- class SimpleNode(Node):
- def __init__(self, vars_to_resolve):
- self.vars_to_resolve = map(Variable, vars_to_resolve)
- def render(self, context):
- resolved_vars = [var.resolve(context) for var in self.vars_to_resolve]
- if takes_context:
- func_args = [context] + resolved_vars
- else:
- func_args = resolved_vars
- return func(*func_args)
- compile_func = curry(generic_tag_compiler, params, defaults, getattr(func, "_decorated_function", func).__name__, SimpleNode)
- compile_func.__doc__ = func.__doc__
- self.tag(getattr(func, "_decorated_function", func).__name__, compile_func)
- return func
- if func is None:
- # @register.simple_tag(...)
- return dec
- elif callable(func):
- # @register.simple_tag
- return dec(func)
- else:
- raise TemplateSyntaxError("Invalid arguments provided to simple_tag")
- def inclusion_tag(self, file_name, context_class=Context, takes_context=False):
- def dec(func):
- params, xx, xxx, defaults = getargspec(func)
- if takes_context:
- if params[0] == 'context':
- params = params[1:]
- else:
- raise TemplateSyntaxError("Any tag function decorated with takes_context=True must have a first argument of 'context'")
- class InclusionNode(Node):
- def __init__(self, vars_to_resolve):
- self.vars_to_resolve = map(Variable, vars_to_resolve)
- def render(self, context):
- resolved_vars = [var.resolve(context) for var in self.vars_to_resolve]
- if takes_context:
- args = [context] + resolved_vars
- else:
- args = resolved_vars
- dict = func(*args)
- if not getattr(self, 'nodelist', False):
- from django.template.loader import get_template, select_template
- if not isinstance(file_name, basestring) and is_iterable(file_name):
- t = select_template(file_name)
- else:
- t = get_template(file_name)
- self.nodelist = t.nodelist
- new_context = context_class(dict, autoescape=context.autoescape)
- # Copy across the CSRF token, if present, because inclusion
- # tags are often used for forms, and we need instructions
- # for using CSRF protection to be as simple as possible.
- csrf_token = context.get('csrf_token', None)
- if csrf_token is not None:
- new_context['csrf_token'] = csrf_token
- return self.nodelist.render(new_context)
- compile_func = curry(generic_tag_compiler, params, defaults, getattr(func, "_decorated_function", func).__name__, InclusionNode)
- compile_func.__doc__ = func.__doc__
- self.tag(getattr(func, "_decorated_function", func).__name__, compile_func)
- return func
- return dec
- def import_library(taglib_module):
- """Load a template tag library module.
- Verifies that the library contains a 'register' attribute, and
- returns that attribute as the representation of the library
- """
- app_path, taglib = taglib_module.rsplit('.',1)
- app_module = import_module(app_path)
- try:
- mod = import_module(taglib_module)
- except ImportError, e:
- # If the ImportError is because the taglib submodule does not exist, that's not
- # an error that should be raised. If the submodule exists and raised an ImportError
- # on the attempt to load it, that we want to raise.
- if not module_has_submodule(app_module, taglib):
- return None
- else:
- raise InvalidTemplateLibrary("ImportError raised loading %s: %s" % (taglib_module, e))
- try:
- return mod.register
- except AttributeError:
- raise InvalidTemplateLibrary("Template library %s does not have a variable named 'register'" % taglib_module)
- templatetags_modules = []
- def get_templatetags_modules():
- """Return the list of all available template tag modules.
- Caches the result for faster access.
- """
- global templatetags_modules
- if not templatetags_modules:
- _templatetags_modules = []
- # Populate list once per thread.
- for app_module in ['django'] + list(settings.INSTALLED_APPS):
- try:
- templatetag_module = '%s.templatetags' % app_module
- import_module(templatetag_module)
- _templatetags_modules.append(templatetag_module)
- except ImportError:
- continue
- templatetags_modules = _templatetags_modules
- return templatetags_modules
- def get_library(library_name):
- """
- Load the template library module with the given name.
- If library is not already loaded loop over all templatetags modules to locate it.
- {% load somelib %} and {% load someotherlib %} loops twice.
- Subsequent loads eg. {% load somelib %} in the same process will grab the cached
- module from libraries.
- """
- lib = libraries.get(library_name, None)
- if not lib:
- templatetags_modules = get_templatetags_modules()
- tried_modules = []
- for module in templatetags_modules:
- taglib_module = '%s.%s' % (module, library_name)
- tried_modules.append(taglib_module)
- lib = import_library(taglib_module)
- if lib:
- libraries[library_name] = lib
- break
- if not lib:
- raise InvalidTemplateLibrary("Template library %s not found, tried %s" % (library_name, ','.join(tried_modules)))
- return lib
- def add_to_builtins(module):
- builtins.append(import_library(module))
- add_to_builtins('django.template.defaulttags')
- add_to_builtins('django.template.defaultfilters')