JezK
Edit File: parsetree.py
# 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