Enhancement: jinja template support for workflow title assignment (#10700)

---------

Co-authored-by: Trenton Holmes <797416+stumpylog@users.noreply.github.com>
Co-authored-by: shamoon <4887959+shamoon@users.noreply.github.com>

src/documents/templating/filepath.py

@@ -2,22 +2,16 @@ import logging
 import os
 import re
 from collections.abc import Iterable
-from datetime import date
-from datetime import datetime
 from pathlib import PurePath
 
 import pathvalidate
-from babel import Locale
-from babel import dates
 from django.utils import timezone
-from django.utils.dateparse import parse_date
 from django.utils.text import slugify as django_slugify
 from jinja2 import StrictUndefined
 from jinja2 import Template
 from jinja2 import TemplateSyntaxError
 from jinja2 import UndefinedError
 from jinja2 import make_logging_undefined
-from jinja2.sandbox import SandboxedEnvironment
 from jinja2.sandbox import SecurityError
 
 from documents.models import Correspondent
@@ -27,39 +21,16 @@ from documents.models import Document
 from documents.models import DocumentType
 from documents.models import StoragePath
 from documents.models import Tag
+from documents.templating.environment import _template_environment
+from documents.templating.filters import format_datetime
+from documents.templating.filters import get_cf_value
+from documents.templating.filters import localize_date
 
 logger = logging.getLogger("paperless.templating")
 
 _LogStrictUndefined = make_logging_undefined(logger, StrictUndefined)
 
 
-class FilePathEnvironment(SandboxedEnvironment):
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-        self.undefined_tracker = None
-
-    def is_safe_callable(self, obj):
-        # Block access to .save() and .delete() methods
-        if callable(obj) and getattr(obj, "__name__", None) in (
-            "save",
-            "delete",
-            "update",
-        ):
-            return False
-        # Call the parent method for other cases
-        return super().is_safe_callable(obj)
-
-
-_template_environment = FilePathEnvironment(
-    trim_blocks=True,
-    lstrip_blocks=True,
-    keep_trailing_newline=False,
-    autoescape=False,
-    extensions=["jinja2.ext.loopcontrols"],
-    undefined=_LogStrictUndefined,
-)
-
-
 class FilePathTemplate(Template):
     def render(self, *args, **kwargs) -> str:
         def clean_filepath(value: str) -> str:
@@ -81,54 +52,7 @@ class FilePathTemplate(Template):
         return clean_filepath(original_render)
 
 
-def get_cf_value(
-    custom_field_data: dict[str, dict[str, str]],
-    name: str,
-    default: str | None = None,
-) -> str | None:
-    if name in custom_field_data and custom_field_data[name]["value"] is not None:
-        return custom_field_data[name]["value"]
-    elif default is not None:
-        return default
-    return None
-
-
-def format_datetime(value: str | datetime, format: str) -> str:
-    if isinstance(value, str):
-        value = parse_date(value)
-    return value.strftime(format=format)
-
-
-def localize_date(value: date | datetime, format: str, locale: str) -> str:
-    """
-    Format a date or datetime object into a localized string using Babel.
-
-    Args:
-        value (date | datetime): The date or datetime to format. If a datetime
-            is provided, it should be timezone-aware (e.g., UTC from a Django DB object).
-        format (str): The format to use. Can be one of Babel's preset formats
-            ('short', 'medium', 'long', 'full') or a custom pattern string.
-        locale (str): The locale code (e.g., 'en_US', 'fr_FR') to use for
-            localization.
-
-    Returns:
-        str: The localized, formatted date string.
-
-    Raises:
-        TypeError: If `value` is not a date or datetime instance.
-    """
-    try:
-        Locale.parse(locale)
-    except Exception as e:
-        raise ValueError(f"Invalid locale identifier: {locale}") from e
-
-    if isinstance(value, datetime):
-        return dates.format_datetime(value, format=format, locale=locale)
-    elif isinstance(value, date):
-        return dates.format_date(value, format=format, locale=locale)
-    else:
-        raise TypeError(f"Unsupported type {type(value)} for localize_date")
-
+_template_environment.undefined = _LogStrictUndefined
 
 _template_environment.filters["get_cf_value"] = get_cf_value