Fix: include replace none logic in storage path preview, improve jinja conditionals for empty metadata (#11315)

src/documents/templating/filepath.py

@@ -52,6 +52,33 @@ class FilePathTemplate(Template):
         return clean_filepath(original_render)
 
 
+class PlaceholderString(str):
+    """
+    String subclass used as a sentinel for empty metadata values inside templates.
+
+    - Renders as \"-none-\" to preserve existing filename cleaning logic.
+    - Compares equal to either \"-none-\" or \"none\" so templates can check for either.
+    - Evaluates to False so {% if correspondent %} behaves intuitively.
+    """
+
+    def __new__(cls, value: str = "-none-"):
+        return super().__new__(cls, value)
+
+    def __bool__(self) -> bool:
+        return False
+
+    def __eq__(self, other) -> bool:
+        if isinstance(other, str) and other == "none":
+            other = "-none-"
+        return super().__eq__(other)
+
+    def __ne__(self, other) -> bool:
+        return not self.__eq__(other)
+
+
+NO_VALUE_PLACEHOLDER = PlaceholderString("-none-")
+
+
 _template_environment.undefined = _LogStrictUndefined
 
 _template_environment.filters["get_cf_value"] = get_cf_value
@@ -128,7 +155,7 @@ def get_added_date_context(document: Document) -> dict[str, str]:
 def get_basic_metadata_context(
     document: Document,
     *,
-    no_value_default: str,
+    no_value_default: str = NO_VALUE_PLACEHOLDER,
 ) -> dict[str, str]:
     """
     Given a Document, constructs some basic information about it.  If certain values are not set,
@@ -266,7 +293,7 @@ def validate_filepath_template_and_render(
     # Build the context dictionary
     context = (
         {"document": document}
-        | get_basic_metadata_context(document, no_value_default="-none-")
+        | get_basic_metadata_context(document, no_value_default=NO_VALUE_PLACEHOLDER)
         | get_creation_date_context(document)
         | get_added_date_context(document)
         | get_tags_context(tags_list)