feat: lazy global translated strings

frappe/__init__.py

@@ -118,6 +118,12 @@ def _(msg: str, lang: str | None = None, context: str | None = None) -> str:
 	return translated_string or non_translated_string
 
 
+def _lt(msg: str, lang: str | None = None, context: str | None = None):
+	from frappe.translate import LazyTranslate
+
+	return LazyTranslate(msg, lang, context)
+
+
 def as_unicode(text, encoding: str = "utf-8") -> str:
 	"""Convert to unicode if required."""
 	if isinstance(text, str):

frappe/model/__init__.py

@@ -3,7 +3,7 @@
 
 # model __init__.py
 import frappe
-from frappe import _
+from frappe import _, _lt
 
 data_fieldtypes = (
 	"Currency",
@@ -134,22 +134,22 @@ log_types = (
 )
 
 std_fields = [
-	{"fieldname": "name", "fieldtype": "Link", "label": _("ID")},
-	{"fieldname": "owner", "fieldtype": "Link", "label": _("Created By"), "options": "User"},
-	{"fieldname": "idx", "fieldtype": "Int", "label": _("Index")},
-	{"fieldname": "creation", "fieldtype": "Datetime", "label": _("Created On")},
-	{"fieldname": "modified", "fieldtype": "Datetime", "label": _("Last Updated On")},
+	{"fieldname": "name", "fieldtype": "Link", "label": _lt("ID")},
+	{"fieldname": "owner", "fieldtype": "Link", "label": _lt("Created By"), "options": "User"},
+	{"fieldname": "idx", "fieldtype": "Int", "label": _lt("Index")},
+	{"fieldname": "creation", "fieldtype": "Datetime", "label": _lt("Created On")},
+	{"fieldname": "modified", "fieldtype": "Datetime", "label": _lt("Last Updated On")},
 	{
 		"fieldname": "modified_by",
 		"fieldtype": "Link",
-		"label": _("Last Updated By"),
+		"label": _lt("Last Updated By"),
 		"options": "User",
 	},
-	{"fieldname": "_user_tags", "fieldtype": "Data", "label": _("Tags")},
-	{"fieldname": "_liked_by", "fieldtype": "Data", "label": _("Liked By")},
-	{"fieldname": "_comments", "fieldtype": "Text", "label": _("Comments")},
-	{"fieldname": "_assign", "fieldtype": "Text", "label": _("Assigned To")},
-	{"fieldname": "docstatus", "fieldtype": "Int", "label": _("Document Status")},
+	{"fieldname": "_user_tags", "fieldtype": "Data", "label": _lt("Tags")},
+	{"fieldname": "_liked_by", "fieldtype": "Data", "label": _lt("Liked By")},
+	{"fieldname": "_comments", "fieldtype": "Text", "label": _lt("Comments")},
+	{"fieldname": "_assign", "fieldtype": "Text", "label": _lt("Assigned To")},
+	{"fieldname": "docstatus", "fieldtype": "Int", "label": _lt("Document Status")},
 ]
 
 

frappe/model/meta.py

@@ -22,7 +22,7 @@ from datetime import datetime
 import click
 
 import frappe
-from frappe import _
+from frappe import _, _lt
 from frappe.model import (
 	child_table_fields,
 	data_fieldtypes,
@@ -42,17 +42,17 @@ from frappe.modules import load_doctype_module
 from frappe.utils import cast, cint, cstr
 
 DEFAULT_FIELD_LABELS = {
-	"name": lambda: _("ID"),
-	"creation": lambda: _("Created On"),
-	"docstatus": lambda: _("Document Status"),
-	"idx": lambda: _("Index"),
-	"modified": lambda: _("Last Updated On"),
-	"modified_by": lambda: _("Last Updated By"),
-	"owner": lambda: _("Created By"),
-	"_user_tags": lambda: _("Tags"),
-	"_liked_by": lambda: _("Liked By"),
-	"_comments": lambda: _("Comments"),
-	"_assign": lambda: _("Assigned To"),
+	"name": _lt("ID"),
+	"creation": _lt("Created On"),
+	"docstatus": _lt("Document Status"),
+	"idx": _lt("Index"),
+	"modified": _lt("Last Updated On"),
+	"modified_by": _lt("Last Updated By"),
+	"owner": _lt("Created By"),
+	"_user_tags": _lt("Tags"),
+	"_liked_by": _lt("Liked By"),
+	"_comments": _lt("Comments"),
+	"_assign": _lt("Assigned To"),
 }
 
 
@@ -249,7 +249,7 @@ class Meta(Document):
 			return df.get("label")
 
 		if fieldname in DEFAULT_FIELD_LABELS:
-			return DEFAULT_FIELD_LABELS[fieldname]()
+			return str(DEFAULT_FIELD_LABELS[fieldname])
 
 		return "No Label"
 

frappe/tests/test_translate.py

@@ -7,7 +7,7 @@ from unittest.mock import patch
 
 import frappe
 import frappe.translate
-from frappe import _
+from frappe import _, _lt
 from frappe.gettext.extractors.javascript import extract_javascript
 from frappe.tests.utils import FrappeTestCase
 from frappe.translate import (
@@ -32,6 +32,9 @@ first_lang, second_lang, third_lang, fourth_lang, fifth_lang = choices(
 )
 
 
+_lazy_translations = _lt("Communication")
+
+
 class TestTranslate(FrappeTestCase):
 	guest_sessions_required = [
 		"test_guest_request_language_resolution_with_cookie",
@@ -46,6 +49,7 @@ class TestTranslate(FrappeTestCase):
 		frappe.form_dict.pop("_lang", None)
 		if self._testMethodName in self.guest_sessions_required:
 			frappe.set_user("Administrator")
+		frappe.local.lang = "en"
 
 	def test_clear_cache(self):
 		_("Trigger caching")
@@ -79,7 +83,6 @@ class TestTranslate(FrappeTestCase):
 			self.assertEqual(ext_line, exp_line)
 
 	def test_read_language_variant(self):
-		frappe.local.lang = "en"
 		self.assertEqual(_("Mobile No"), "Mobile No")
 		try:
 			frappe.local.lang = "pt-BR"
@@ -91,12 +94,24 @@ class TestTranslate(FrappeTestCase):
 			self.assertEqual(_("Mobile No"), "Mobile No")
 
 	def test_translation_with_context(self):
-		try:
-			frappe.local.lang = "fr"
-			self.assertEqual(_("Change"), "Changement")
-			self.assertEqual(_("Change", context="Coins"), "la monnaie")
-		finally:
-			frappe.local.lang = "en"
+		frappe.local.lang = "fr"
+		self.assertEqual(_("Change"), "Changement")
+		self.assertEqual(_("Change", context="Coins"), "la monnaie")
+
+	def test_lazy_translations(self):
+		frappe.local.lang = "de"
+		eager_translation = _("Communication")
+		self.assertEqual(str(_lazy_translations), eager_translation)
+		self.assertRaises(NotImplementedError, lambda: _lazy_translations == "blah")
+
+		# auto casts when added or radded
+		self.assertEqual(_lazy_translations + "A", eager_translation + "A")
+		x = _lazy_translations
+		x += "A"
+		self.assertEqual(x, eager_translation + "A")
+
+		# f string usually auto-casts
+		self.assertEqual(f"{_lazy_translations}", eager_translation)
 
 	def test_request_language_resolution_with_form_dict(self):
 		"""Test for frappe.translate.get_language

frappe/translate.py

@@ -1105,6 +1105,44 @@ def print_language(language: str):
 	frappe.local.jenv = _jenv
 
 
+@functools.total_ordering
+class LazyTranslate:
+	__slots__ = ("msg", "lang", "context")
+
+	def __init__(self, msg: str, lang: str | None = None, context: str | None = None) -> None:
+		self.msg = msg
+		self.lang = lang
+		self.context = context
+
+	@property
+	def value(self) -> str:
+		return frappe._(str(self.msg), self.lang, self.context)
+
+	def __str__(self):
+		return self.value
+
+	def __add__(self, other):
+		if isinstance(other, (str, LazyTranslate)):
+			return self.value + str(other)
+		raise NotImplementedError
+
+	def __radd__(self, other):
+		if isinstance(other, (str, LazyTranslate)):
+			return str(other) + self.value
+		return NotImplementedError
+
+	def __repr__(self) -> str:
+		return f"'{self.value}'"
+
+	# NOTE: it's required to override these methods and raise error as default behaviour will
+	# return `False` in all cases.
+	def __eq__(self, other):
+		raise NotImplementedError
+
+	def __lt__(self, other):
+		raise NotImplementedError
+
+
 # Backward compatibility
 get_full_dict = get_all_translations
 load_lang = get_translations_from_apps

frappe/utils/password_strength.py

@@ -7,7 +7,7 @@ from zxcvbn import zxcvbn
 from zxcvbn.scoring import ALL_UPPER, START_UPPER
 
 import frappe
-from frappe import _
+from frappe import _, _lt
 
 if TYPE_CHECKING:
 	from collections.abc import Iterable
@@ -41,8 +41,8 @@ def test_password_strength(password: str, user_inputs: "Iterable[object]" = None
 default_feedback: "PasswordStrengthFeedback" = {
 	"warning": "",
 	"suggestions": [
-		_("Use a few words, avoid common phrases."),
-		_("No need for symbols, digits, or uppercase letters."),
+		_lt("Use a few words, avoid common phrases."),
+		_lt("No need for symbols, digits, or uppercase letters."),
 	],
 }