refactor: allow multiple payment requests through customer portal

[ruthra-kumar]

Issue

Customer is unable to pay for an Invoice through customer portal if he accidentally refreshes or navigates back on the Payment screen

Screenshots

erpnext/erpnext/accounts/doctype/payment_request/payment_request.py

Lines 562 to 570 in 07f8899

	# fetches existing payment request `grand_total` amount
	existing_payment_request_amount = get_existing_payment_request_amount(ref_doc.doctype, ref_doc.name)
	if existing_payment_request_amount:
	grand_total -= existing_payment_request_amount
	if not grand_total:
	frappe.throw(_("Payment Request is already created"))

Solution

1. Cancel old Payment Requests; Isolated to Customer Portal.
2. Set status of Integration Requests of above cancelled PR's as 'Cancelled'
3. Checkout page will disallow Cancelled tokens refactor: Disallow cancelled 'Integration Requests' on checkout page payments#115

[ruthra-kumar]

@vorasmit Would like your thoughts on this.

[vorasmit]

Just saw this:

This issue will mainly arise for webshop or customer portal, integrated with payment gateway.
A setting for this may not be necessary.

Suggestion:

In my opinion,

• introduce a status to payment request for invalidating the payment link if already generated (say Invalid). This may involve invalidating payment gateway order too, so that customers cannot pay using old links.
• when this is created from portal, invalidate old requests and create a new one.
• ensure payment entries cannot be created from invalidated payment requests.