def parse_primary(self, with_postfix=True):
token = self.stream.current
if token.type == 'name':
if token.value in ('true', 'false', 'True', 'False'):
node = nodes.Const(token.value in ('true', 'True'),
lineno=token.lineno)
elif token.value in ('none', 'None'):
node = nodes.Const(None, lineno=token.lineno)
else:
node = nodes.Name(token.value, 'load', lineno=token.lineno)
next(self.stream)
elif token.type == 'string':
next(self.stream)
buf = [token.value]
lineno = token.lineno
while self.stream.current.type == 'string':
buf.append(self.stream.current.value)
next(self.stream)
node = nodes.Const(''.join(buf), lineno=lineno)
elif token.type in ('integer', 'float'):
next(self.stream)
node = nodes.Const(token.value, lineno=token.lineno)
elif token.type == 'lparen':
next(self.stream)
node = self.parse_tuple()
self.stream.expect('rparen')
elif token.type == 'lbracket':
node = self.parse_list()
elif token.type == 'lbrace':
node = self.parse_dict()
else:
self.fail("unexpected token '%s'" % (token, ), token.lineno)
if with_postfix:
node = self.parse_postfix(node)
return node
def parse_assign_target(self,
with_tuple=True,
name_only=False,
extra_end_rules=None):
"""Parse an assignment target. As Jinja2 allows assignments to
tuples, this function can parse all allowed assignment targets. Per
default assignments to tuples are parsed, that can be disable however
by setting `with_tuple` to `False`. If only assignments to names are
wanted `name_only` can be set to `True`. The `extra_end_rules`
parameter is forwarded to the tuple parsing function.
"""
if name_only:
token = self.stream.expect('name')
target = nodes.Name(token.value, 'store', lineno=token.lineno)
else:
if with_tuple:
target = self.parse_tuple(simplified=True,
extra_end_rules=extra_end_rules)
else:
target = self.parse_primary(with_postfix=False)
target.set_ctx('store')
if not target.can_assign():
self.fail(
'can\'t assign to %r' % target.__class__.__name__.lower(),
target.lineno)
return target
def _make_node(self, singular, plural, variables, plural_expr):
"""Generates a useful node from the data provided."""
# singular only:
if plural_expr is None:
gettext = nodes.Name('gettext', 'load')
node = nodes.Call(gettext, [nodes.Const(singular)], [], None, None)
# singular and plural
else:
ngettext = nodes.Name('ngettext', 'load')
node = nodes.Call(
ngettext,
[nodes.Const(singular),
nodes.Const(plural), plural_expr], [], None, None)
# mark the return value as safe if we are in an
# environment with autoescaping turned on
if self.environment.autoescape:
node = nodes.MarkSafe(node)
if variables:
node = nodes.Mod(node, variables)
return nodes.Output([node])
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
**new in Jinja 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)
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 parse(self, parser):
"""Parse a translatable tag."""
lineno = next(parser.stream).lineno
# find all the variables referenced. Additionally a variable can be
# defined in the body of the trans block too, but this is checked at
# a later state.
plural_expr = None
variables = {}
while parser.stream.current.type != 'block_end':
if variables:
parser.stream.expect('comma')
# skip colon for python compatibility
if parser.stream.skip_if('colon'):
break
name = parser.stream.expect('name')
if name.value in variables:
parser.fail('translatable variable %r defined twice.' %
name.value,
name.lineno,
exc=TemplateAssertionError)
# expressions
if parser.stream.current.type == 'assign':
next(parser.stream)
variables[name.value] = var = parser.parse_expression()
else:
variables[name.value] = var = nodes.Name(name.value, 'load')
if plural_expr is None:
plural_expr = var
parser.stream.expect('block_end')
plural = plural_names = None
have_plural = False
referenced = set()
# now parse until endtrans or pluralize
singular_names, singular = self._parse_block(parser, True)
if singular_names:
referenced.update(singular_names)
if plural_expr is None:
plural_expr = nodes.Name(singular_names[0], 'load')
# if we have a pluralize block, we parse that too
if parser.stream.current.test('name:pluralize'):
have_plural = True
next(parser.stream)
if parser.stream.current.type != 'block_end':
name = parser.stream.expect('name')
if name.value not in variables:
parser.fail('unknown variable %r for pluralization' %
name.value,
name.lineno,
exc=TemplateAssertionError)
plural_expr = variables[name.value]
parser.stream.expect('block_end')
plural_names, plural = self._parse_block(parser, False)
next(parser.stream)
referenced.update(plural_names)
else:
next(parser.stream)
# register free names as simple name expressions
for var in referenced:
if var not in variables:
variables[var] = nodes.Name(var, 'load')
# no variables referenced? no need to escape
if not referenced:
singular = singular.replace('%%', '%')
if plural:
plural = plural.replace('%%', '%')
if not have_plural:
plural_expr = None
elif plural_expr is None:
parser.fail('pluralize without variables', lineno)
if variables:
variables = nodes.Dict([
nodes.Pair(nodes.Const(x, lineno=lineno), y)
for x, y in variables.items()
])
else:
variables = None
node = self._make_node(singular, plural, variables, plural_expr)
node.set_lineno(lineno)
return node