Refs #34521 -- Added __slots__ to template Node classes.

django/contrib/admin/templatetags/base.py

@@ -9,6 +9,8 @@ class InclusionAdminNode(InclusionNode):
     or globally.
     """
 
+    __slots__ = ("template_name",)
+
     def __init__(self, parser, token, func, template_name, takes_context=True):
         self.template_name = template_name
         params, varargs, varkw, defaults, kwonly, kwonly_defaults, _ = getfullargspec(

django/contrib/admin/templatetags/log.py

@@ -4,7 +4,10 @@ register = template.Library()
 
 
 class AdminLogNode(template.Node):
+    __slots__ = ("limit", "varname", "user")
+
     def __init__(self, limit, varname, user):
+        super().__init__()
         self.limit = limit
         self.varname = varname
         self.user = user

django/contrib/flatpages/templatetags/flatpages.py

@@ -7,7 +7,10 @@ register = template.Library()
 
 
 class FlatpageNode(template.Node):
+    __slots__ = ("context_name", "starts_with", "user")
+
     def __init__(self, context_name, starts_with=None, user=None):
+        super().__init__()
         self.context_name = context_name
         if starts_with:
             self.starts_with = template.Variable(starts_with)

django/template/base.py

@@ -290,6 +290,8 @@ def linebreak_iter(template_source):
 
 
 class Token:
+    __slots__ = ("token_type", "contents", "position", "lineno")
+
     def __init__(self, token_type, contents, position=None, lineno=None):
         """
         A token representing a string from the template.
@@ -338,6 +340,8 @@ class Token:
 
 
 class Lexer:
+    __slots__ = ("template_string", "verbatim")
+
     def __init__(self, template_string):
         self.template_string = template_string
         self.verbatim = False
@@ -399,6 +403,8 @@ class Lexer:
 
 
 class DebugLexer(Lexer):
+    __slots__ = ()
+
     def _tag_re_split_positions(self):
         last = 0
         for match in tag_re.finditer(self.template_string):
@@ -950,11 +956,16 @@ class Variable:
 
 
 class Node:
+    __slots__ = ("token", "origin")
+
     # Set this to True for nodes that must be first in the template (although
     # they can be preceded by text nodes.
     must_be_first = False
     child_nodelists = ("nodelist",)
-    token = None
+
+    def __init__(self):
+        self.token = None
+        self.origin = None
 
     def render(self, context):
         """
@@ -1004,9 +1015,13 @@ class Node:
 
 
 class NodeList(list):
-    # Set to True the first time a non-TextNode is inserted by
-    # extend_nodelist().
-    contains_nontext = False
+    __slots__ = ("contains_nontext",)
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        # Set to True the first time a non-TextNode is inserted by
+        # extend_nodelist().
+        self.contains_nontext = False
 
     def render(self, context):
         return SafeString("".join([node.render_annotated(context) for node in self]))
@@ -1020,9 +1035,12 @@ class NodeList(list):
 
 
 class TextNode(Node):
+    __slots__ = ("s",)
+
     child_nodelists = ()
 
     def __init__(self, s):
+        super().__init__()
         self.s = s
 
     def __repr__(self):
@@ -1058,9 +1076,11 @@ def render_value_in_context(value, context):
 
 
 class VariableNode(Node):
+    __slots__ = ("filter_expression",)
     child_nodelists = ()
 
     def __init__(self, filter_expression):
+        super().__init__()
         self.filter_expression = filter_expression
 
     def __repr__(self):

django/template/defaulttags.py

@@ -45,7 +45,10 @@ register = Library()
 class AutoEscapeControlNode(Node):
     """Implement the actions of the autoescape tag."""
 
+    __slots__ = ("setting", "nodelist")
+
     def __init__(self, setting, nodelist):
+        super().__init__()
         self.setting = setting
         self.nodelist = nodelist
 
@@ -61,6 +64,7 @@ class AutoEscapeControlNode(Node):
 
 
 class CommentNode(Node):
+    __slots__ = ()
     child_nodelists = ()
 
     def render(self, context):
@@ -68,6 +72,7 @@ class CommentNode(Node):
 
 
 class CsrfTokenNode(Node):
+    __slots__ = ()
     child_nodelists = ()
 
     def render(self, context):
@@ -93,7 +98,10 @@ class CsrfTokenNode(Node):
 
 
 class CycleNode(Node):
+    __slots__ = ("cyclevars", "variable_name", "silent")
+
     def __init__(self, cyclevars, variable_name=None, silent=False):
+        super().__init__()
         self.cyclevars = cyclevars
         self.variable_name = variable_name
         self.silent = silent
@@ -118,6 +126,8 @@ class CycleNode(Node):
 
 
 class DebugNode(Node):
+    __slots__ = ()
+
     def render(self, context):
         if not settings.DEBUG:
             return ""
@@ -131,7 +141,13 @@ class DebugNode(Node):
 
 
 class FilterNode(Node):
+    __slots__ = (
+        "filter_expr",
+        "nodelist",
+    )
+
     def __init__(self, filter_expr, nodelist):
+        super().__init__()
         self.filter_expr = filter_expr
         self.nodelist = nodelist
 
@@ -143,7 +159,10 @@ class FilterNode(Node):
 
 
 class FirstOfNode(Node):
+    __slots__ = ("vars", "asvar")
+
     def __init__(self, variables, asvar=None):
+        super().__init__()
         self.vars = variables
         self.asvar = asvar
 
@@ -161,11 +180,19 @@ class FirstOfNode(Node):
 
 
 class ForNode(Node):
+    __slots__ = (
+        "loopvars",
+        "sequence",
+        "is_reversed",
+        "nodelist_loop",
+        "nodelist_empty",
+    )
     child_nodelists = ("nodelist_loop", "nodelist_empty")
 
     def __init__(
         self, loopvars, sequence, is_reversed, nodelist_loop, nodelist_empty=None
     ):
+        super().__init__()
         self.loopvars = loopvars
         self.sequence = sequence
         self.is_reversed = is_reversed
@@ -251,9 +278,11 @@ class ForNode(Node):
 
 
 class IfChangedNode(Node):
+    __slots__ = ("nodelist_true", "nodelist_false", "_varlist")
     child_nodelists = ("nodelist_true", "nodelist_false")
 
     def __init__(self, nodelist_true, nodelist_false, *varlist):
+        super().__init__()
         self.nodelist_true = nodelist_true
         self.nodelist_false = nodelist_false
         self._varlist = varlist
@@ -299,7 +328,10 @@ class IfChangedNode(Node):
 
 
 class IfNode(Node):
+    __slots__ = ("conditions_nodelists",)
+
     def __init__(self, conditions_nodelists):
+        super().__init__()
         self.conditions_nodelists = conditions_nodelists
 
     def __repr__(self):
@@ -330,7 +362,10 @@ class IfNode(Node):
 
 
 class LoremNode(Node):
+    __slots__ = ("count", "method", "common")
+
     def __init__(self, count, method, common):
+        super().__init__()
         self.count = count
         self.method = method
         self.common = common
@@ -353,7 +388,10 @@ GroupedResult = namedtuple("GroupedResult", ["grouper", "list"])
 
 
 class RegroupNode(Node):
+    __slots__ = ("target", "expression", "var_name")
+
     def __init__(self, target, expression, var_name):
+        super().__init__()
         self.target = target
         self.expression = expression
         self.var_name = var_name
@@ -382,6 +420,8 @@ class RegroupNode(Node):
 
 
 class LoadNode(Node):
+    __slots__ = ()
+
     child_nodelists = ()
 
     def render(self, context):
@@ -389,7 +429,10 @@ class LoadNode(Node):
 
 
 class NowNode(Node):
+    __slots__ = ("format_string", "asvar")
+
     def __init__(self, format_string, asvar=None):
+        super().__init__()
         self.format_string = format_string
         self.asvar = asvar
 
@@ -405,7 +448,10 @@ class NowNode(Node):
 
 
 class ResetCycleNode(Node):
+    __slots__ = ("node",)
+
     def __init__(self, node):
+        super().__init__()
         self.node = node
 
     def render(self, context):
@@ -414,7 +460,10 @@ class ResetCycleNode(Node):
 
 
 class SpacelessNode(Node):
+    __slots__ = ("nodelist",)
+
     def __init__(self, nodelist):
+        super().__init__()
         self.nodelist = nodelist
 
     def render(self, context):
@@ -424,6 +473,8 @@ class SpacelessNode(Node):
 
 
 class TemplateTagNode(Node):
+    __slots__ = ("tagtype",)
+
     mapping = {
         "openblock": BLOCK_TAG_START,
         "closeblock": BLOCK_TAG_END,
@@ -436,6 +487,7 @@ class TemplateTagNode(Node):
     }
 
     def __init__(self, tagtype):
+        super().__init__()
         self.tagtype = tagtype
 
     def render(self, context):
@@ -443,9 +495,12 @@ class TemplateTagNode(Node):
 
 
 class URLNode(Node):
+    __slots__ = ("view_name", "args", "kwargs", "asvar")
+
     child_nodelists = ()
 
     def __init__(self, view_name, args, kwargs, asvar):
+        super().__init__()
         self.view_name = view_name
         self.args = args
         self.kwargs = kwargs
@@ -492,7 +547,10 @@ class URLNode(Node):
 
 
 class VerbatimNode(Node):
+    __slots__ = ("content",)
+
     def __init__(self, content):
+        super().__init__()
         self.content = content
 
     def render(self, context):
@@ -500,7 +558,15 @@ class VerbatimNode(Node):
 
 
 class WidthRatioNode(Node):
+    __slots__ = (
+        "val_expr",
+        "max_expr",
+        "max_width",
+        "asvar",
+    )
+
     def __init__(self, val_expr, max_expr, max_width, asvar=None):
+        super().__init__()
         self.val_expr = val_expr
         self.max_expr = max_expr
         self.max_width = max_width
@@ -533,7 +599,10 @@ class WidthRatioNode(Node):
 
 
 class WithNode(Node):
+    __slots__ = ("nodelist", "extra_context")
+
     def __init__(self, var, name, nodelist, extra_context=None):
+        super().__init__()
         self.nodelist = nodelist
         # var and name are legacy attributes, being left in case they are used
         # by third-party subclasses of this Node.

django/template/library.py

@@ -211,7 +211,10 @@ class TagHelperNode(Node):
     function.
     """
 
+    __slots__ = ("func", "takes_context", "args", "kwargs")
+
     def __init__(self, func, takes_context, args, kwargs):
+        super().__init__()
         self.func = func
         self.takes_context = takes_context
         self.args = args
@@ -226,6 +229,7 @@ class TagHelperNode(Node):
 
 
 class SimpleNode(TagHelperNode):
+    __slots__ = ("target_var",)
     child_nodelists = ()
 
     def __init__(self, func, takes_context, args, kwargs, target_var):
@@ -244,6 +248,8 @@ class SimpleNode(TagHelperNode):
 
 
 class InclusionNode(TagHelperNode):
+    __slots__ = ("filename",)
+
     def __init__(self, func, takes_context, args, kwargs, filename):
         super().__init__(func, takes_context, args, kwargs)
         self.filename = filename

django/template/loader_tags.py

@@ -40,10 +40,14 @@ class BlockContext:
 
 
 class BlockNode(Node):
+    __slots__ = ("name", "nodelist", "parent", "context")
+
     def __init__(self, name, nodelist, parent=None):
+        super().__init__()
         self.name = name
         self.nodelist = nodelist
         self.parent = parent
+        self.context = None
 
     def __repr__(self):
         return "<Block Node: %s. Contents: %r>" % (self.name, self.nodelist)
@@ -68,9 +72,9 @@ class BlockNode(Node):
         return result
 
     def super(self):
-        if not hasattr(self, "context"):
+        if self.context is None:
             raise TemplateSyntaxError(
-                "'%s' object has no attribute 'context'. Did you use "
+                "'%s' object has no context. Did you use "
                 "{{ block.super }} in a base template?" % self.__class__.__name__
             )
         render_context = self.context.render_context
@@ -83,10 +87,13 @@ class BlockNode(Node):
 
 
 class ExtendsNode(Node):
+    __slots__ = ("nodelist", "parent_name", "template_dirs", "blocks")
+
     must_be_first = True
     context_key = "extends_context"
 
     def __init__(self, nodelist, parent_name, template_dirs=None):
+        super().__init__()
         self.nodelist = nodelist
         self.parent_name = parent_name
         self.template_dirs = template_dirs
@@ -160,6 +167,8 @@ class ExtendsNode(Node):
 
 
 class IncludeNode(Node):
+    __slots__ = ("template", "extra_context", "isolated_context")
+
     context_key = "__include_context"
 
     def __init__(

django/templatetags/cache.py

@@ -6,7 +6,16 @@ register = Library()
 
 
 class CacheNode(Node):
+    __slots__ = (
+        "nodelist",
+        "expire_time_var",
+        "fragment_name",
+        "vary_on",
+        "cache_name",
+    )
+
     def __init__(self, nodelist, expire_time_var, fragment_name, vary_on, cache_name):
+        super().__init__()
         self.nodelist = nodelist
         self.expire_time_var = expire_time_var
         self.fragment_name = fragment_name

django/templatetags/i18n.py

@@ -11,7 +11,10 @@ register = Library()
 
 
 class GetAvailableLanguagesNode(Node):
+    __slots__ = ("variable",)
+
     def __init__(self, variable):
+        super().__init__()
         self.variable = variable
 
     def render(self, context):
@@ -22,7 +25,10 @@ class GetAvailableLanguagesNode(Node):
 
 
 class GetLanguageInfoNode(Node):
+    __slots__ = ("lang_code", "variable")
+
     def __init__(self, lang_code, variable):
+        super().__init__()
         self.lang_code = lang_code
         self.variable = variable
 
@@ -33,7 +39,10 @@ class GetLanguageInfoNode(Node):
 
 
 class GetLanguageInfoListNode(Node):
+    __slots__ = ("languages", "variable")
+
     def __init__(self, languages, variable):
+        super().__init__()
         self.languages = languages
         self.variable = variable
 
@@ -52,7 +61,10 @@ class GetLanguageInfoListNode(Node):
 
 
 class GetCurrentLanguageNode(Node):
+    __slots__ = ("variable",)
+
     def __init__(self, variable):
+        super().__init__()
         self.variable = variable
 
     def render(self, context):
@@ -61,7 +73,10 @@ class GetCurrentLanguageNode(Node):
 
 
 class GetCurrentLanguageBidiNode(Node):
+    __slots__ = ("variable",)
+
     def __init__(self, variable):
+        super().__init__()
         self.variable = variable
 
     def render(self, context):
@@ -70,9 +85,12 @@ class GetCurrentLanguageBidiNode(Node):
 
 
 class TranslateNode(Node):
+    __slots__ = ("noop", "asvar", "message_context", "filter_expression")
+
     child_nodelists = ()
 
     def __init__(self, filter_expression, noop, asvar=None, message_context=None):
+        super().__init__()
         self.noop = noop
         self.asvar = asvar
         self.message_context = message_context
@@ -102,6 +120,18 @@ class TranslateNode(Node):
 
 
 class BlockTranslateNode(Node):
+    __slots__ = (
+        "extra_context",
+        "singular",
+        "plural",
+        "countervar",
+        "counter",
+        "message_context",
+        "trimmed",
+        "asvar",
+        "tag_name",
+    )
+
     def __init__(
         self,
         extra_context,
@@ -114,6 +144,7 @@ class BlockTranslateNode(Node):
         asvar=None,
         tag_name="blocktranslate",
     ):
+        super().__init__()
         self.extra_context = extra_context
         self.singular = singular
         self.plural = plural
@@ -205,7 +236,10 @@ class BlockTranslateNode(Node):
 
 
 class LanguageNode(Node):
+    __slots__ = ("nodelist", "language")
+
     def __init__(self, nodelist, language):
+        super().__init__()
         self.nodelist = nodelist
         self.language = language
 

django/templatetags/l10n.py

@@ -21,7 +21,10 @@ def unlocalize(value):
 
 
 class LocalizeNode(Node):
+    __slots__ = ("nodelist", "use_l10n")
+
     def __init__(self, nodelist, use_l10n):
+        super().__init__()
         self.nodelist = nodelist
         self.use_l10n = use_l10n
 

django/templatetags/static.py

@@ -9,10 +9,13 @@ register = template.Library()
 
 
 class PrefixNode(template.Node):
+    __slots__ = ("varname", "name")
+
     def __repr__(self):
         return "<PrefixNode for %r>" % self.name
 
     def __init__(self, varname=None, name=None):
+        super().__init__()
         if name is None:
             raise template.TemplateSyntaxError(
                 "Prefix nodes must be given a name to return."
@@ -93,9 +96,12 @@ def get_media_prefix(parser, token):
 
 
 class StaticNode(template.Node):
+    __slots__ = ("varname", "path")
+
     child_nodelists = ()
 
     def __init__(self, varname=None, path=None):
+        super().__init__()
         if path is None:
             raise template.TemplateSyntaxError(
                 "Static template nodes must be given a path to return."

django/templatetags/tz.py

@@ -94,7 +94,10 @@ class LocalTimeNode(Node):
     Template node class used by ``localtime_tag``.
     """
 
+    __slots__ = ("nodelist", "use_tz")
+
     def __init__(self, nodelist, use_tz):
+        super().__init__()
         self.nodelist = nodelist
         self.use_tz = use_tz
 
@@ -111,7 +114,10 @@ class TimezoneNode(Node):
     Template node class used by ``timezone_tag``.
     """
 
+    __slots__ = ("nodelist", "tz")
+
     def __init__(self, nodelist, tz):
+        super().__init__()
         self.nodelist = nodelist
         self.tz = tz
 
@@ -126,7 +132,10 @@ class GetCurrentTimezoneNode(Node):
     Template node class used by ``get_current_timezone_tag``.
     """
 
+    __slots__ = ("variable",)
+
     def __init__(self, variable):
+        super().__init__()
         self.variable = variable
 
     def render(self, context):

tests/template_tests/templatetags/custom.py

@@ -211,6 +211,7 @@ def counter(parser, token):
 
 class CounterNode(template.Node):
     def __init__(self):
+        super().__init__()
         self.count = 0
 
     def render(self, context):

tests/template_tests/templatetags/testtags.py

@@ -5,6 +5,7 @@ register = Library()
 
 class EchoNode(Node):
     def __init__(self, contents):
+        super().__init__()
         self.contents = contents
 
     def render(self, context):