ERPNext Syntax: Document Controllers

Document Controllers are Python classes that implement the server-side logic of a DocType.

Quick Reference

Controller Basic Structure

import frappe
from frappe.model.document import Document

class SalesOrder(Document):
    def validate(self):
        """Main validation - runs on every save."""
        if not self.items:
            frappe.throw(_("Items are required"))
        self.total = sum(item.amount for item in self.items)