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# mako/parsetree.py
# Copyright 2006-2022 the Mako authors and contributors <see AUTHORS file>
#
# 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."""
import re
from mako import ast
from mako import exceptions
from mako import filters
from mako import util
class Node:
"""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
@property
def exception_kwargs(self):
return {
"source": self.source,
"lineno": self.lineno,
"pos": self.pos,
"filename": self.filename,
}
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().__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
"""
has_loop_context = False
def __init__(self, keyword, isend, text, **kwargs):
super().__init__(**kwargs)
self.text = text
self.keyword = keyword
self.isend = isend
self.is_primary = keyword in ["for", "if", "while", "try", "with"]
self.nodes = []
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 get_children(self):
return self.nodes
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"""
cases = {
"if": {"else", "elif"},
"try": {"except", "finally"},
"for": {"else"},
}
return keyword in cases.get(self.keyword, set())
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().__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().__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().__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().__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(
filters.DEFAULT_ESCAPES
)
).difference(self.code.declared_identifiers)
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 getattr(cls, "__keyword__", None) is not None:
cls._classmap[cls.__keyword__] = cls
super().__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, metaclass=_TagMeta):
"""abstract base class for tags.
e.g.::
<%sometag/>
<%someothertag>
stuff
</%someothertag>
"""
__keyword__ = None
def __init__(
self,
keyword,
attributes,
expressions,
nonexpressions,
required,
**kwargs,
):
r"""construct a new Tag instance.
this constructor not called directly, and is only called
by subclasses.
:param keyword: the tag keyword
:param attributes: raw dictionary of attribute key/value pairs
:param expressions: a set of identifiers that are legal attributes,
which can also contain embedded expressions
:param nonexpressions: a set of identifiers that are legal
attributes, which cannot contain embedded expressions
:param \**kwargs:
other arguments passed to the Node superclass (lineno, pos)
"""
super().__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.compile(r"(\${.+?})", re.S).split(
self.attributes[key]
):
m = re.compile(r"^\${(.+?)}$", re.S).match(x)
if m:
code = ast.PythonCode(
m.group(1).rstrip(), **self.exception_kwargs
)
# we aren't discarding "declared_identifiers" here,
# which we do so that list comprehension-declared
# variables aren't counted. As yet can't find a
# condition that requires it here.
undeclared_identifiers = undeclared_identifiers.union(
code.undeclared_identifiers
)
expr.append("(%s)" % m.group(1))
elif 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(
"Attribute '%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().__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(
{"__DUMMY"}
).difference(self.page_args.declared_identifiers)
return identifiers.union(super().undeclared_identifiers())
class NamespaceTag(Tag):
__keyword__ = "namespace"
def __init__(self, keyword, attributes, **kwargs):
super().__init__(
keyword,
attributes,
("file",),
("name", "inheritable", "import", "module"),
(),
**kwargs,
)
self.name = attributes.get("name", "__anon_%s" % hex(abs(id(self))))
if "name" not in attributes and "import" not in attributes:
raise exceptions.CompileException(
"'name' and/or 'import' attributes are required "
"for <%namespace>",
**self.exception_kwargs,
)
if "file" in attributes and "module" in attributes:
raise exceptions.CompileException(
"<%namespace> may only have one of 'file' or 'module'",
**self.exception_kwargs,
)
def declared_identifiers(self):
return []
class TextTag(Tag):
__keyword__ = "text"
def __init__(self, keyword, attributes, **kwargs):
super().__init__(keyword, attributes, (), ("filter"), (), **kwargs)
self.filter_args = ast.ArgumentList(
attributes.get("filter", ""), **self.exception_kwargs
)
def undeclared_identifiers(self):
return self.filter_args.undeclared_identifiers.difference(
filters.DEFAULT_ESCAPES.keys()
).union(self.expression_undeclared_identifiers)
class DefTag(Tag):
__keyword__ = "def"
def __init__(self, keyword, attributes, **kwargs):
expressions = ["buffered", "cached"] + [
c for c in attributes if c.startswith("cache_")
]
super().__init__(
keyword,
attributes,
expressions,
("name", "filter", "decorator"),
("name",),
**kwargs,
)
name = attributes["name"]
if re.match(r"^[\w_]+$", name):
raise exceptions.CompileException(
"Missing parenthesis in %def", **self.exception_kwargs
)
self.function_decl = ast.FunctionDecl(
"def " + name + ":pass", **self.exception_kwargs
)
self.name = self.function_decl.funcname
self.decorator = attributes.get("decorator", "")
self.filter_args = ast.ArgumentList(
attributes.get("filter", ""), **self.exception_kwargs
)
is_anonymous = False
is_block = False
@property
def funcname(self):
return self.function_decl.funcname
def get_argument_expressions(self, **kw):
return self.function_decl.get_argument_expressions(**kw)
def declared_identifiers(self):
return self.function_decl.allargnames
def undeclared_identifiers(self):
res = []
for c in self.function_decl.defaults:
res += list(
ast.PythonCode(
c, **self.exception_kwargs
).undeclared_identifiers
)
return (
set(res)
.union(
self.filter_args.undeclared_identifiers.difference(
filters.DEFAULT_ESCAPES.keys()
)
)
.union(self.expression_undeclared_identifiers)
.difference(self.function_decl.allargnames)
)
class BlockTag(Tag):
__keyword__ = "block"
def __init__(self, keyword, attributes, **kwargs):
expressions = ["buffered", "cached", "args"] + [
c for c in attributes if c.startswith("cache_")
]
super().__init__(
keyword,
attributes,
expressions,
("name", "filter", "decorator"),
(),
**kwargs,
)
name = attributes.get("name")
if name and not re.match(r"^[\w_]+$", name):
raise exceptions.CompileException(
"%block may not specify an argument signature",
**self.exception_kwargs,
)
if not name and attributes.get("args", None):
raise exceptions.CompileException(
"Only named %blocks may specify args", **self.exception_kwargs
)
self.body_decl = ast.FunctionArgs(
attributes.get("args", ""), **self.exception_kwargs
)
self.name = name
self.decorator = attributes.get("decorator", "")
self.filter_args = ast.ArgumentList(
attributes.get("filter", ""), **self.exception_kwargs
)
is_block = True
@property
def is_anonymous(self):
return self.name is None
@property
def funcname(self):
return self.name or "__M_anon_%d" % (self.lineno,)
def get_argument_expressions(self, **kw):
return self.body_decl.get_argument_expressions(**kw)
def declared_identifiers(self):
return self.body_decl.allargnames
def undeclared_identifiers(self):
return (
self.filter_args.undeclared_identifiers.difference(
filters.DEFAULT_ESCAPES.keys()
)
).union(self.expression_undeclared_identifiers)
class CallTag(Tag):
__keyword__ = "call"
def __init__(self, keyword, attributes, **kwargs):
super().__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.allargnames)
def undeclared_identifiers(self):
return self.code.undeclared_identifiers.difference(
self.code.declared_identifiers
)
class CallNamespaceTag(Tag):
def __init__(self, namespace, defname, attributes, **kwargs):
super().__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.items()
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.allargnames)
def undeclared_identifiers(self):
return self.code.undeclared_identifiers.difference(
self.code.declared_identifiers
)
class InheritTag(Tag):
__keyword__ = "inherit"
def __init__(self, keyword, attributes, **kwargs):
super().__init__(
keyword, attributes, ("file",), (), ("file",), **kwargs
)
class PageTag(Tag):
__keyword__ = "page"
def __init__(self, keyword, attributes, **kwargs):
expressions = [
"cached",
"args",
"expression_filter",
"enable_loop",
] + [c for c in attributes if c.startswith("cache_")]
super().__init__(keyword, attributes, expressions, (), (), **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.allargnames
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