1 files changed, 70 insertions, 0 deletions
diff --git a/mako/ext/autohandler.py b/mako/ext/autohandler.py
new file mode 100644
index 0000000..c33f080
--- /dev/null
+++ b/mako/ext/autohandler.py
@@ -0,0 +1,70 @@
+# ext/autohandler.py
+# Copyright 2006-2023 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
+
+"""adds autohandler functionality to Mako templates.
+
+requires that the TemplateLookup class is used with templates.
+
+usage::
+
+    <%!
+        from mako.ext.autohandler import autohandler
+    %>
+    <%inherit file="${autohandler(template, context)}"/>
+
+
+or with custom autohandler filename::
+
+    <%!
+        from mako.ext.autohandler import autohandler
+    %>
+    <%inherit file="${autohandler(template, context, name='somefilename')}"/>
+
+"""
+
+import os
+import posixpath
+import re
+
+
+def autohandler(template, context, name="autohandler"):
+    lookup = context.lookup
+    _template_uri = template.module._template_uri
+    if not lookup.filesystem_checks:
+        try:
+            return lookup._uri_cache[(autohandler, _template_uri, name)]
+        except KeyError:
+            pass
+
+    tokens = re.findall(r"([^/]+)", posixpath.dirname(_template_uri)) + [name]
+    while len(tokens):
+        path = "/" + "/".join(tokens)
+        if path != _template_uri and _file_exists(lookup, path):
+            if not lookup.filesystem_checks:
+                return lookup._uri_cache.setdefault(
+                    (autohandler, _template_uri, name), path
+                )
+            else:
+                return path
+        if len(tokens) == 1:
+            break
+        tokens[-2:] = [name]
+
+    if not lookup.filesystem_checks:
+        return lookup._uri_cache.setdefault(
+            (autohandler, _template_uri, name), None
+        )
+    else:
+        return None
+
+
+def _file_exists(lookup, path):
+    psub = re.sub(r"^/", "", path)
+    for d in lookup.directories:
+        if os.path.exists(d + "/" + psub):
+            return True
+    else:
+        return False