Initial Commit

lib/mako/parsetree.py

@@ -0,0 +1,594 @@
+# mako/parsetree.py
+# Copyright (C) 2006-2015 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."""
+
+from mako import exceptions, ast, util, filters, compat
+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
+
+    @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(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
+
+    """
+
+    has_loop_context = False
+
+    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', '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"""
+
+        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())
+                )
+            ).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(_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(compat.with_metaclass(_TagMeta, Node)):
+    """abstract base class for tags.
+
+    <%sometag/>
+
+    <%someothertag>
+        stuff
+    </%someothertag>
+
+    """
+    __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.
+
+        :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(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.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))
+                    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"])).\
+                            difference(self.page_args.declared_identifiers)
+        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,
+                                        ('file',),
+                                        ('name','inheritable',
+                                        '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)
+        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(TextTag, self).__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(DefTag, self).__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(BlockTag, self).__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(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.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(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.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(InheritTag, self).__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(PageTag, self).__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
+
+