added a function to parse assign targes and documented it for the extension interface
--HG--
branch : trunk
diff --git a/jinja2/parser.py b/jinja2/parser.py
index 427cb05..dae1a6b 100644
--- a/jinja2/parser.py
+++ b/jinja2/parser.py
@@ -121,14 +121,9 @@
def parse_for(self):
"""Parse a for loop."""
lineno = self.stream.expect('name:for').lineno
- target = self.parse_tuple(simplified=True)
- if not target.can_assign():
- raise TemplateSyntaxError("can't assign to '%s'" %
- target.__class__.__name__.lower(),
- target.lineno, self.filename)
- target.set_ctx('store')
+ target = self.parse_assign_target()
self.stream.expect('name:in')
- iter = self.parse_tuple(no_condexpr=True)
+ iter = self.parse_tuple(with_condexpr=False)
test = None
if self.stream.current.test('name:if'):
self.stream.next()
@@ -144,7 +139,7 @@
"""Parse an if construct."""
node = result = nodes.If(lineno=self.stream.expect('name:if').lineno)
while 1:
- node.test = self.parse_tuple(no_condexpr=True)
+ node.test = self.parse_tuple(with_condexpr=False)
node.body = self.parse_statements(('name:elif', 'name:else',
'name:endif'))
token = self.stream.next()
@@ -190,11 +185,7 @@
node = nodes.Import(lineno=self.stream.next().lineno)
node.template = self.parse_expression()
self.stream.expect('name:as')
- node.target = self.stream.expect('name').value
- if not nodes.Name(node.target, 'store').can_assign():
- raise TemplateSyntaxError('can\'t assign imported template '
- 'to %r' % node.target, node.lineno,
- self.filename)
+ node.target = self.parse_assign_target(name_only=True).name
return self.parse_import_context(node, False)
def parse_from(self):
@@ -217,25 +208,16 @@
if self.stream.current.type is 'name':
if parse_context():
break
- target = nodes.Name(self.stream.current.value, 'store')
- if not target.can_assign():
- raise TemplateSyntaxError('can\'t import object named %r'
- % target.name, target.lineno,
- self.filename)
- elif target.name.startswith('__'):
+ target = self.parse_assign_target(name_only=True)
+ if target.name.startswith('__'):
raise TemplateAssertionError('names starting with two '
'underscores can not be '
'imported', target.lineno,
self.filename)
- self.stream.next()
if self.stream.current.test('name:as'):
self.stream.next()
- alias = self.stream.expect('name')
- if not nodes.Name(alias.value, 'store').can_assign():
- raise TemplateSyntaxError('can\'t name imported '
- 'object %r.' % alias.value,
- alias.lineno, self.filename)
- node.names.append((target.name, alias.value))
+ alias = self.parse_assign_target(name_only=True)
+ node.names.append((target.name, alias.name))
else:
node.names.append(target.name)
if parse_context() or self.stream.current.type is not 'comma':
@@ -255,12 +237,7 @@
while self.stream.current.type is not 'rparen':
if args:
self.stream.expect('comma')
- token = self.stream.expect('name')
- arg = nodes.Name(token.value, 'param', lineno=token.lineno)
- if not arg.can_assign():
- raise TemplateSyntaxError("can't assign to '%s'" %
- arg.name, arg.lineno,
- self.filename)
+ arg = self.parse_assign_target(name_only=True)
if self.stream.current.type is 'assign':
self.stream.next()
defaults.append(self.parse_expression())
@@ -291,12 +268,7 @@
def parse_macro(self):
node = nodes.Macro(lineno=self.stream.next().lineno)
- node.name = self.stream.expect('name').value
- # make sure that assignments to that name are allowed
- if not nodes.Name(node.name, 'store').can_assign():
- raise TemplateSyntaxError('can\'t assign macro to %r' %
- node.target, node.lineno,
- self.filename)
+ node.name = self.parse_assign_target(name_only=True).name
self.parse_signature(node)
node.body = self.parse_statements(('name:endmacro',),
drop_needle=True)
@@ -311,14 +283,36 @@
node.nodes.append(self.parse_expression())
return node
- def parse_expression(self, no_condexpr=False):
+ def parse_assign_target(self, with_tuple=True, name_only=False):
+ """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`.
+ """
+ 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)
+ else:
+ target = self.parse_primary(with_postfix=False)
+ target.set_ctx('store')
+ if not target.can_assign():
+ raise TemplateSyntaxError('can\'t assign to %r' %
+ target.__class__.__name__.lower(),
+ target.lineno, self.filename)
+ return target
+
+ def parse_expression(self, with_condexpr=True):
"""Parse an expression. Per default all expressions are parsed, if
- the optional `no_condexpr` parameter is set to `True` conditional
+ the optional `with_condexpr` parameter is set to `False` conditional
expressions are not parsed.
"""
- if no_condexpr:
- return self.parse_or()
- return self.parse_condexpr()
+ if with_condexpr:
+ return self.parse_condexpr()
+ return self.parse_or()
def parse_condexpr(self):
lineno = self.stream.current.lineno
@@ -472,7 +466,7 @@
return nodes.Pos(node, lineno=lineno)
return self.parse_primary()
- def parse_primary(self, parse_postfix=True):
+ def parse_primary(self, with_postfix=True):
token = self.stream.current
if token.type is 'name':
if token.value in ('true', 'false'):
@@ -497,11 +491,11 @@
raise TemplateSyntaxError("unexpected token '%s'" %
(token,), token.lineno,
self.filename)
- if parse_postfix:
+ if with_postfix:
node = self.parse_postfix(node)
return node
- def parse_tuple(self, simplified=False, no_condexpr=False):
+ def parse_tuple(self, simplified=False, with_condexpr=True):
"""Works like `parse_expression` but if multiple expressions are
delimited by a comma a :class:`~jinja2.nodes.Tuple` node is created.
This method could also return a regular expression instead of a tuple
@@ -513,11 +507,11 @@
"""
lineno = self.stream.current.lineno
if simplified:
- parse = self.parse_primary
- elif no_condexpr:
- parse = lambda: self.parse_expression(no_condexpr=True)
- else:
+ parse = lambda: self.parse_primary(with_postfix=False)
+ elif with_condexpr:
parse = self.parse_expression
+ else:
+ parse = lambda: self.parse_expression(with_condexpr=False)
args = []
is_tuple = False
while 1:
@@ -741,7 +735,7 @@
self.stream.next()
elif token.type is 'variable_begin':
self.stream.next()
- add_data(self.parse_tuple())
+ add_data(self.parse_tuple(with_condexpr=True))
self.stream.expect('variable_end')
elif token.type is 'block_begin':
flush_data()