Fixed #35899 -- Allowed multiline template tags.

django/template/backends/django.py

@@ -22,6 +22,7 @@ class DjangoTemplates(BaseEngine):
         options.setdefault("autoescape", True)
         options.setdefault("debug", settings.DEBUG)
         options.setdefault("file_charset", "utf-8")
+        options.setdefault("multiline", False)
         libraries = options.get("libraries", {})
         options["libraries"] = self.get_templatetag_libraries(libraries)
         super().__init__(params)

django/template/base.py

@@ -86,7 +86,8 @@ UNKNOWN_SOURCE = "<unknown source>"
 # Match BLOCK_TAG_*, VARIABLE_TAG_*, and COMMENT_TAG_* tags and capture the
 # entire tag, including start/end delimiters. Using re.compile() is faster
 # than instantiating SimpleLazyObject with _lazy_re_compile().
-tag_re = re.compile(r"({%.*?%}|{{.*?}}|{#.*?#})")
+tag_re = re.compile(r"({%.*?%}|{{.*?}}|{#.*?#})", re.DOTALL)
+tag_re_legacy = re.compile(r"({%.*?%}|{{.*?}}|{#.*?#})")
 
 logger = logging.getLogger("django.template")
 
@@ -180,9 +181,9 @@ class Template:
         template source.
         """
         if self.engine.debug:
-            lexer = DebugLexer(self.source)
+            lexer = DebugLexer(self.source, multiline=self.engine.multiline)
         else:
-            lexer = Lexer(self.source)
+            lexer = Lexer(self.source, multiline=self.engine.multiline)
 
         tokens = lexer.tokenize()
         parser = Parser(
@@ -338,9 +339,11 @@ class Token:
 
 
 class Lexer:
-    def __init__(self, template_string):
+    def __init__(self, template_string, multiline=False):
         self.template_string = template_string
         self.verbatim = False
+        self.multiline = multiline
+        self.tag_re = tag_re if multiline else tag_re_legacy
 
     def __repr__(self):
         return '<%s template_string="%s...", verbatim=%s>' % (
@@ -356,7 +359,7 @@ class Lexer:
         in_tag = False
         lineno = 1
         result = []
-        for token_string in tag_re.split(self.template_string):
+        for token_string in self.tag_re.split(self.template_string):
             if token_string:
                 result.append(self.create_token(token_string, None, lineno, in_tag))
                 lineno += token_string.count("\n")
@@ -401,7 +404,7 @@ class Lexer:
 class DebugLexer(Lexer):
     def _tag_re_split_positions(self):
         last = 0
-        for match in tag_re.finditer(self.template_string):
+        for match in self.tag_re.finditer(self.template_string):
             start, end = match.span()
             yield last, start
             yield start, end

django/template/engine.py

@@ -1,9 +1,11 @@
 import functools
+import warnings
 
 from django.core.exceptions import ImproperlyConfigured
 from django.utils.functional import cached_property
 from django.utils.module_loading import import_string
 
+from ..utils.deprecation import RemovedInDjango60Warning
 from .base import Template
 from .context import Context, _builtin_context_processors
 from .exceptions import TemplateDoesNotExist
@@ -29,7 +31,13 @@ class Engine:
         libraries=None,
         builtins=None,
         autoescape=True,
+        multiline=False,
     ):
+        if not multiline:
+            warnings.warn(
+                "Multiline tags in templates will become the default in Django 6.0",
+                RemovedInDjango60Warning,
+            )
         if dirs is None:
             dirs = []
         if context_processors is None:
@@ -61,6 +69,7 @@ class Engine:
         self.template_libraries = self.get_template_libraries(libraries)
         self.builtins = self.default_builtins + builtins
         self.template_builtins = self.get_template_builtins(self.builtins)
+        self.multiline = multiline
 
     def __repr__(self):
         return (

tests/runtests.py

@@ -46,6 +46,12 @@ else:
 # Make deprecation warnings errors to ensure no usage of deprecated features.
 warnings.simplefilter("error", RemovedInDjango60Warning)
 warnings.simplefilter("error", RemovedInDjango61Warning)
+# Ignore this message as the test suite uses the default
+warnings.filterwarnings(
+    "ignore",
+    message="Multiline tags in templates will become the default in Django 6.0",
+    category=RemovedInDjango60Warning,
+)
 # Make resource and runtime warning errors to ensure no usage of error prone
 # patterns.
 warnings.simplefilter("error", ResourceWarning)

tests/template_tests/syntax_tests/test_basic.py

@@ -210,11 +210,21 @@ class BasicSyntaxTests(SimpleTestCase):
     @setup({"basic-syntax24": "{{ moo\n }}"})
     def test_basic_syntax24(self):
         """
-        Embedded newlines make it not-a-tag.
+        Embedded newlines make it not-a-tag if not in multiline mode.
         """
         output = self.engine.render_to_string("basic-syntax24")
         self.assertEqual(output, "{{ moo\n }}")
 
+    @setup({"basic-syntax24-multiline": "{{ \nfoo\n }}"})
+    def test_basic_syntax24_multiline(self):
+        """
+        Embedded newlines are ok in multiline mode.
+        """
+        output = self.multiline_engine.render_to_string(
+            "basic-syntax24-multiline", {"foo": "bar"}
+        )
+        self.assertEqual(output, "bar")
+
     # Literal strings are permitted inside variables, mostly for i18n
     # purposes.
     @setup({"basic-syntax25": '{{ "fred" }}'})
@@ -325,6 +335,39 @@ class BasicSyntaxTests(SimpleTestCase):
         )
         self.assertEqual(output, "foo bar")
 
+    @setup(
+        {
+            "basic-syntax39-multiline": """
+                {% if
+                    foo
+                %}
+                    a
+                {%
+                    else
+                %}
+                    b
+                {%
+                    endif
+                %}
+                {#
+                    comment
+                #}
+                """
+        }
+    )
+    def test_basic_syntax39_multiline(self):
+        """
+        Embedded newlines are ok in multiline mode.
+        """
+        output = self.multiline_engine.render_to_string(
+            "basic-syntax39-multiline", {"foo": True}
+        ).strip()
+        self.assertEqual(output, "a")
+        output = self.multiline_engine.render_to_string(
+            "basic-syntax39-multiline", {"foo": False}
+        ).strip()
+        self.assertEqual(output, "b")
+
     @setup({"template": "{% block content %}"})
     def test_unclosed_block(self):
         msg = "Unclosed tag on line 1: 'block'. Looking for one of: endblock."

tests/template_tests/test_parser.py

@@ -45,6 +45,13 @@ class ParserTests(SimpleTestCase):
             '<Lexer template_string="{% for i in 1 %}{{ a...", verbatim=False>',
         )
 
+    def test_repr_multiline(self):
+        lexer = Lexer("{% \nfor i in 1\n %}{{ a }}\n{% \nendfor \n%}", multiline=True)
+        self.assertEqual(
+            repr(lexer),
+            '<Lexer template_string="{% for i in 1 %}{{...", verbatim=False>',
+        )
+
     def test_filter_parsing(self):
         c = {"article": {"section": "News"}}
         p = Parser("", builtins=[filter_library])

tests/template_tests/utils.py

@@ -55,6 +55,11 @@ def setup(templates, *args, test_once=False):
                 libraries=libraries,
                 loaders=loaders,
             )
+            self.multiline_engine = Engine(
+                libraries=libraries,
+                loaders=loaders,
+                multiline=True,
+            )
             func(self)
             if test_once:
                 return
@@ -65,6 +70,12 @@ def setup(templates, *args, test_once=False):
                 loaders=loaders,
                 string_if_invalid="INVALID",
             )
+            self.multiline_engine = Engine(
+                libraries=libraries,
+                loaders=loaders,
+                string_if_invalid="INVALID",
+                multiline=True,
+            )
             func(self)
             func(self)
 
@@ -73,6 +84,12 @@ def setup(templates, *args, test_once=False):
                 libraries=libraries,
                 loaders=loaders,
             )
+            self.multiline_engine = Engine(
+                debug=True,
+                libraries=libraries,
+                loaders=loaders,
+                multiline=True,
+            )
             func(self)
             func(self)