fix: Add rename_doc utils for external API usages

* The previously deleted code was being used in ERPNext's Customer
module.
* This will be moved into frappe.model.utils.rename_doc for the time
and completely removed in time.

frappe/model/rename_doc.py

@@ -2,6 +2,7 @@
 # MIT License. See license.txt
 
 from __future__ import unicode_literals, print_function
+from click.termui import secho
 import frappe
 from frappe import _, bold
 from frappe.utils import cint
@@ -488,3 +489,32 @@ def bulk_rename(doctype, rows=None, via_console = False):
 
 	if not via_console:
 		return rename_log
+
+def update_linked_doctypes(doctype, docname, linked_to, value, ignore_doctypes=None):
+	from frappe.model.utils.rename_doc import update_linked_doctypes
+	show_deprecation_warning("update_linked_doctypes")
+
+	return update_linked_doctypes(
+		doctype=doctype,
+		docname=docname,
+		linked_to=linked_to,
+		value=value,
+		ignore_doctypes=ignore_doctypes,
+	)
+
+
+def get_fetch_fields(doctype, linked_to, ignore_doctypes=None):
+	from frappe.model.utils.rename_doc import get_fetch_fields
+	show_deprecation_warning("get_fetch_fields")
+
+	return get_fetch_fields(
+		doctype=doctype, linked_to=linked_to, ignore_doctypes=ignore_doctypes
+	)
+
+def show_deprecation_warning(funct):
+	from click import secho
+	message = (
+		f"Function frappe.model.rename_doc.{funct} has been deprecated and "
+		"moved to the frappe.model.utils.rename_doc"
+	)
+	secho(message, fg="yellow")

frappe/model/utils/rename_doc.py

@@ -0,0 +1,58 @@
+from itertools import product
+
+import frappe
+from frappe.model.rename_doc import get_link_fields
+
+
+def update_linked_doctypes(doctype, docname, linked_to, value, ignore_doctypes=None):
+	"""
+	linked_doctype_info_list = list formed by get_fetch_fields() function
+	docname = Master DocType's name in which modification are made
+	value = Value for the field thats set in other DocType's by fetching from Master DocType
+	"""
+	linked_doctype_info_list = get_fetch_fields(doctype, linked_to, ignore_doctypes)
+
+	for d in linked_doctype_info_list:
+		frappe.db.set_value(
+			d.doctype,
+			{
+				d.master_fieldname : docname,
+				d.linked_to_fieldname : ("!=", value),
+			},
+			d.linked_to_fieldname,
+			value,
+		)
+
+
+def get_fetch_fields(doctype, linked_to, ignore_doctypes=None):
+	"""
+	doctype = Master DocType in which the changes are being made
+	linked_to = DocType name of the field thats being updated in Master
+	This function fetches list of all DocType where both doctype and linked_to is found
+	as link fields.
+	Forms a list of dict in the form -
+		[{doctype: , master_fieldname: , linked_to_fieldname: ]
+	where
+		doctype = DocType where changes need to be made
+		master_fieldname = Fieldname where options = doctype
+		linked_to_fieldname = Fieldname where options = linked_to
+	"""
+
+	out = []
+	master_list = get_link_fields(doctype)
+	linked_to_list = get_link_fields(linked_to)
+	product_list = product(master_list, linked_to_list)
+
+	for d in product_list:
+		linked_doctype_info = frappe._dict()
+		if (
+			d[0]["parent"] == d[1]["parent"]
+			and (not ignore_doctypes or d[0]["parent"] not in ignore_doctypes)
+			and not d[1]["issingle"]
+		):
+			linked_doctype_info.doctype = d[0]["parent"]
+			linked_doctype_info.master_fieldname = d[0]["fieldname"]
+			linked_doctype_info.linked_to_fieldname = d[1]["fieldname"]
+			out.append(linked_doctype_info)
+
+	return out