fix: correctly update outstanding amount and add validation for stude…

education/hooks.py

@@ -186,13 +186,13 @@
 # ---------------
 # Hook on document methods and events
 
-# doc_events = {
-# 	"*": {
-# 		"on_update": "method",
-# 		"on_cancel": "method",
-# 		"on_trash": "method"
-# 	}
-# }
+doc_events = {
+	"Payment Entry": {
+		"validate": "education.overrides.payment_entry.get_valid_reference_doctypes",
+		"on_submit": "education.overrides.payment_entry.set_outstanding_amount",
+		"on_cancel": "education.overrides.payment_entry.set_outstanding_amount",
+	}
+}
 
 # Scheduled Tasks
 # ---------------

education/overrides/payment_entry.py

@@ -0,0 +1,100 @@
+import frappe
+from frappe import _, scrub
+from frappe.utils import comma_or, flt
+
+
+def get_valid_reference_doctypes(self, method):
+	valid_reference_doctypes = ()
+
+	if self.party_type == "Student":
+		valid_reference_doctypes = ("Fees", "Journal Entry")
+
+	if not valid_reference_doctypes:
+		return
+
+	for d in self.get("references"):
+		if not d.allocated_amount:
+			continue
+
+		if d.reference_doctype not in valid_reference_doctypes:
+			frappe.throw(
+				_("Reference Doctype must be one of {0}").format(
+					comma_or([_(d) for d in valid_reference_doctypes])
+				)
+			)
+
+		elif d.reference_name:
+			if not frappe.db.exists(d.reference_doctype, d.reference_name):
+				frappe.throw(
+					_("{0} {1} does not exist").format(d.reference_doctype, d.reference_name)
+				)
+
+			ref_doc = frappe.get_doc(d.reference_doctype, d.reference_name)
+
+			if d.reference_doctype != "Journal Entry":
+				if self.party != ref_doc.get(scrub(self.party_type)):
+					frappe.throw(
+						_("{0} {1} is not associated with {2} {3}").format(
+							_(d.reference_doctype), d.reference_name, _(self.party_type), self.party
+						)
+					)
+			else:
+				self.validate_journal_entry()
+
+			if d.reference_doctype in ("Fees"):
+				if self.party_type == "Student":
+					ref_party_account = ref_doc.receivable_account
+
+				if ref_party_account != self.party_account:
+					frappe.throw(
+						_("{0} {1} is associated with {2}, but Party Account is {3}").format(
+							_(d.reference_doctype), d.reference_name, ref_party_account, self.party_account
+						)
+					)
+
+			if ref_doc.docstatus != 1:
+				frappe.throw(
+					_("{0} {1} must be submitted").format(_(d.reference_doctype), d.reference_name)
+				)
+
+
+def set_outstanding_amount(self, method):
+	if self.party_type == "Student":
+		for d in self.get("references"):
+			if not d.allocated_amount:
+				continue
+
+			ref_details = get_reference_details(
+				d.reference_doctype,
+				d.reference_name,
+			)
+
+			for field, value in ref_details.items():
+				if d.exchange_gain_loss:
+					# for cases where gain/loss is booked into invoice
+					# exchange_gain_loss is calculated from invoice & populated
+					# and row.exchange_rate is already set to payment entry's exchange rate
+					# refer -> `update_reference_in_payment_entry()` in utils.py
+					continue
+
+				d.db_set(field, value)
+
+
+def get_reference_details(reference_doctype, reference_name):
+	total_amount = outstanding_amount = exchange_rate = bill_no = None
+	ref_doc = frappe.get_doc(reference_doctype, reference_name)
+
+	if reference_doctype == "Fees":
+		total_amount = ref_doc.get("grand_total")
+		exchange_rate = 1
+		outstanding_amount = ref_doc.get("outstanding_amount")
+
+	return frappe._dict(
+		{
+			"due_date": ref_doc.get("due_date"),
+			"total_amount": flt(total_amount),
+			"outstanding_amount": flt(outstanding_amount),
+			"exchange_rate": flt(exchange_rate),
+			"bill_no": bill_no,
+		}
+	)