# parsetree.py
# Copyright (C) 2006, 2007, 2008, 2009, 2010 Michael Bayer mike_mp@zzzcomputing.com
#
# This module is part of Mako and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
"""defines the parse tree components for Mako templates."""
from mako import exceptions,ast,util,filters
import re
class Node(object):
"""base class for a Node in the parse tree."""
def __init__(self, source, lineno, pos, filename):
self.source = source
self.lineno = lineno
self.pos = pos
self.filename = filename
def exception_kwargs(self):
return {'source':self.source, 'lineno':self.lineno, 'pos':self.pos, 'filename':self.filename}
exception_kwargs = property(exception_kwargs)
def get_children(self):
return []
def accept_visitor(self, visitor):
def traverse(node):
for n in node.get_children():
n.accept_visitor(visitor)
method = getattr(visitor, "visit" + self.__class__.__name__, traverse)
method(self)
class TemplateNode(Node):
"""a 'container' node that stores the overall collection of nodes."""
def __init__(self, filename):
super(TemplateNode, self).__init__('', 0, 0, filename)
self.nodes = []
self.page_attributes = {}
def get_children(self):
return self.nodes
def __repr__(self):
return "TemplateNode(%s, %r)" % (util.sorted_dict_repr(self.page_attributes), self.nodes)
class ControlLine(Node):
"""defines a control line, a line-oriented python line or end tag.
e.g.::
% if foo:
(markup)
% endif
"""
def __init__(self, keyword, isend, text, **kwargs):
super(ControlLine, self).__init__(**kwargs)
self.text = text
self.keyword = keyword
self.isend = isend
self.is_primary = keyword in ['for','if', 'while', 'try']
if self.isend:
self._declared_identifiers = []
self._undeclared_identifiers = []
else:
code = ast.PythonFragment(text, **self.exception_kwargs)
self._declared_identifiers = code.declared_identifiers
self._undeclared_identifiers = code.undeclared_identifiers
def declared_identifiers(self):
return self._declared_identifiers
def undeclared_identifiers(self):
return self._undeclared_identifiers
def is_ternary(self, keyword):
"""return true if the given keyword is a ternary keyword for this ControlLine"""
return keyword in {
'if':set(['else', 'elif']),
'try':set(['except', 'finally']),
'for':set(['else'])
}.get(self.keyword, [])
def __repr__(self):
return "ControlLine(%r, %r, %r, %r)" % (
self.keyword,
self.text,
self.isend,
(self.lineno, self.pos)
)
class Text(Node):
"""defines plain text in the template."""
def __init__(self, content, **kwargs):
super(Text, self).__init__(**kwargs)
self.content = content
def __repr__(self):
return "Text(%r, %r)" % (self.content, (self.lineno, self.pos))
class Code(Node):
"""defines a Python code block, either inline or module level.
e.g.::
inline:
<%
x = 12
%>
module level:
<%!
import logger
%>
"""
def __init__(self, text, ismodule, **kwargs):
super(Code, self).__init__(**kwargs)
self.text = text
self.ismodule = ismodule
self.code = ast.PythonCode(text, **self.exception_kwargs)
def declared_identifiers(self):
return self.code.declared_identifiers
def undeclared_identifiers(self):
return self.code.undeclared_identifiers
def __repr__(self):
return "Code(%r, %r, %r)" % (
self.text,
self.ismodule,
(self.lineno, self.pos)
)
class Comment(Node):
"""defines a comment line.
# this is a comment
"""
def __init__(self, text, **kwargs):
super(Comment, self).__init__(**kwargs)
self.text = text
def __repr__(self):
return "Comment(%r, %r)" % (self.text, (self.lineno, self.pos))
class Expression(Node):
"""defines an inline expression.
${x+y}
"""
def __init__(self, text, escapes, **kwargs):
super(Expression, self).__init__(**kwargs)
self.text = text
self.escapes = escapes
self.escapes_code = ast.ArgumentList(escapes, **self.exception_kwargs)
self.code = ast.PythonCode(text, **self.exception_kwargs)
def declared_identifiers(self):
return []
def undeclared_identifiers(self):
# TODO: make the "filter" shortcut list configurable at parse/gen time
return self.code.undeclared_identifiers.union(
self.escapes_code.undeclared_identifiers.difference(
set(filters.DEFAULT_ESCAPES.keys())
)
)
def __repr__(self):
return "Expression(%r, %r, %r)" % (
self.text,
self.escapes_code.args,
(self.lineno, self.pos)
)
class _TagMeta(type):
"""metaclass to allow Tag to produce a subclass according to its keyword"""
_classmap = {}
def __init__(cls, clsname, bases, dict):
if cls.__keyword__ is not None:
cls._classmap[cls.__keyword__] = cls
super(_TagMeta, cls).__init__(clsname, bases, dict)
def __call__(cls, keyword, attributes, **kwargs):
if ":" in keyword:
ns, defname = keyword.split(':')
return type.__call__(CallNamespaceTag, ns, defname, attributes, **kwargs)
try:
cls = _TagMeta._classmap[keyword]
except KeyError:
raise exceptions.CompileException(
"No such tag: '%s'" % keyword,
source=kwargs['source'],
lineno=kwargs['lineno'],
pos=kwargs['pos'],
filename=kwargs['filename']
)
return type.__call__(cls, keyword, attributes, **kwargs)
class Tag(Node):
"""abstract base class for tags.
<%sometag/>
<%someothertag>
stuff
</%someothertag>
"""
__metaclass__ = _TagMeta
__keyword__ = None
def __init__(self, keyword, attributes, expressions, nonexpressions, required, **kwargs):
"""construct a new Tag instance.
this constructor not called directly, and is only called by subclasses.
keyword - the tag keyword
attributes - raw dictionary of attribute key/value pairs
expressions - a set of identifiers that are legal attributes,
which can also contain embedded expressions
nonexpressions - a set of identifiers that are legal attributes,
which cannot contain embedded expressions
\**kwargs - other arguments passed to the Node superclass (lineno, pos)
"""
super(Tag, self).__init__(**kwargs)
self.keyword = keyword
self.attributes = attributes
self._parse_attributes(expressions, nonexpressions)
missing = [r for r in required if r not in self.parsed_attributes]
if len(missing):
raise exceptions.CompileException(
"Missing attribute(s): %s" % ",".join([repr(m) for m in missing]),
**self.exception_kwargs)
self.parent = None
self.nodes = []
def is_root(self):
return self.parent is None
def get_children(self):
return self.nodes
def _parse_attributes(self, expressions, nonexpressions):
undeclared_identifiers = set()
self.parsed_attributes = {}
for key in self.attributes:
if key in expressions:
expr = []
for x in re.split(r'(\${.+?})', self.attributes[key]):
m = re.match(r'^\${(.+?)}$', x)
if m:
code = ast.PythonCode(m.group(1), **self.exception_kwargs)
undeclared_identifiers = undeclared_identifiers.union(
code.undeclared_identifiers
)
expr.append("(%s)" % m.group(1))
else:
if x:
expr.append(repr(x))
self.parsed_attributes[key] = " + ".join(expr) or repr('')
elif key in nonexpressions:
if re.search(r'${.+?}', self.attributes[key]):
raise exceptions.CompileException(
"Attibute '%s' in tag '%s' does not allow embedded "
"expressions" % (key, self.keyword),
**self.exception_kwargs)
self.parsed_attributes[key] = repr(self.attributes[key])
else:
raise exceptions.CompileException(
"Invalid attribute for tag '%s': '%s'" %
(self.keyword, key),
**self.exception_kwargs)
self.expression_undeclared_identifiers = undeclared_identifiers
def declared_identifiers(self):
return []
def undeclared_identifiers(self):
return self.expression_undeclared_identifiers
def __repr__(self):
return "%s(%r, %s, %r, %r)" % (self.__class__.__name__,
self.keyword,
util.sorted_dict_repr(self.attributes),
(self.lineno, self.pos),
self.nodes
)
class IncludeTag(Tag):
__keyword__ = 'include'
def __init__(self, keyword, attributes, **kwargs):
super(IncludeTag, self).__init__(
keyword,
attributes,
('file', 'import', 'args'),
(), ('file',), **kwargs)
self.page_args = ast.PythonCode(
"__DUMMY(%s)" % attributes.get('args', ''),
**self.exception_kwargs)
def declared_identifiers(self):
return []
def undeclared_identifiers(self):
identifiers = self.page_args.undeclared_identifiers.difference(set(["__DUMMY"]))
return identifiers.union(super(IncludeTag, self).undeclared_identifiers())
class NamespaceTag(Tag):
__keyword__ = 'namespace'
def __init__(self, keyword, attributes, **kwargs):
super(NamespaceTag, self).__init__(
keyword, attributes,
(),
('name','inheritable',
'file','import','module'),
(), **kwargs)
self.name = attributes.get('name', '__anon_%s' % hex(abs(id(self))))
if not 'name' in attributes and not 'import' in attributes:
raise exceptions.CompileException(
"'name' and/or 'import' attributes are required "
"for <%namespace>",
**self.exception_kwargs)
def declared_identifiers(self):
return []
class TextTag(Tag):
__keyword__ = 'text'
def __init__(self, keyword, attributes, **kwargs):
super(TextTag, self).__init__(
keyword,
attributes, (),
('filter'), (), **kwargs)
self.filter_args = ast.ArgumentList(
attributes.get('filter', ''),
**self.exception_kwargs)
class DefTag(Tag):
__keyword__ = 'def'
def __init__(self, keyword, attributes, **kwargs):
super(DefTag, self).__init__(
keyword,
attributes,
('buffered', 'cached', 'cache_key', 'cache_timeout',
'cache_type', 'cache_dir', 'cache_url'),
('name','filter', 'decorator'),
('name',),
**kwargs)
name = attributes['name']
if re.match(r'^[\w_]+$',name):
raise exceptions.CompileException(
"Missing parenthesis in %def",
**self.exception_kwargs)
self.function_decl = ast.FunctionDecl("def " + name + ":pass", **self.exception_kwargs)
self.name = self.function_decl.funcname
self.decorator = attributes.get('decorator', '')
self.filter_args = ast.ArgumentList(
attributes.get('filter', ''),
**self.exception_kwargs)
def declared_identifiers(self):
return self.function_decl.argnames
def undeclared_identifiers(self):
res = []
for c in self.function_decl.defaults:
res += list(ast.PythonCode(c, **self.exception_kwargs).undeclared_identifiers)
return res + list(self.filter_args.\
undeclared_identifiers.\
difference(filters.DEFAULT_ESCAPES.keys())
)
class CallTag(Tag):
__keyword__ = 'call'
def __init__(self, keyword, attributes, **kwargs):
super(CallTag, self).__init__(keyword, attributes,
('args'), ('expr',), ('expr',), **kwargs)
self.expression = attributes['expr']
self.code = ast.PythonCode(self.expression, **self.exception_kwargs)
self.body_decl = ast.FunctionArgs(attributes.get('args', ''), **self.exception_kwargs)
def declared_identifiers(self):
return self.code.declared_identifiers.union(self.body_decl.argnames)
def undeclared_identifiers(self):
return self.code.undeclared_identifiers
class CallNamespaceTag(Tag):
def __init__(self, namespace, defname, attributes, **kwargs):
super(CallNamespaceTag, self).__init__(
namespace + ":" + defname,
attributes,
tuple(attributes.keys()) + ('args', ),
(),
(),
**kwargs)
self.expression = "%s.%s(%s)" % (
namespace,
defname,
",".join(["%s=%s" % (k, v) for k, v in
self.parsed_attributes.iteritems()
if k != 'args'])
)
self.code = ast.PythonCode(self.expression, **self.exception_kwargs)
self.body_decl = ast.FunctionArgs(
attributes.get('args', ''),
**self.exception_kwargs)
def declared_identifiers(self):
return self.code.declared_identifiers.union(self.body_decl.argnames)
def undeclared_identifiers(self):
return self.code.undeclared_identifiers
class InheritTag(Tag):
__keyword__ = 'inherit'
def __init__(self, keyword, attributes, **kwargs):
super(InheritTag, self).__init__(
keyword, attributes,
('file',), (), ('file',), **kwargs)
class PageTag(Tag):
__keyword__ = 'page'
def __init__(self, keyword, attributes, **kwargs):
super(PageTag, self).__init__(
keyword,
attributes,
('cached', 'cache_key', 'cache_timeout',
'cache_type', 'cache_dir', 'cache_url',
'args', 'expression_filter'),
(),
(),
**kwargs)
self.body_decl = ast.FunctionArgs(attributes.get('args', ''), **self.exception_kwargs)
self.filter_args = ast.ArgumentList(
attributes.get('expression_filter', ''),
**self.exception_kwargs)
def declared_identifiers(self):
return self.body_decl.argnames
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