Generate DocType Controller

Create document controller classes with lifecycle methods following Frappe patterns.

When to Use

Need business logic for DocType
Want lifecycle hooks (validate, before_insert, etc.)
Prefer class-based controllers
Need reusable methods

Core Patterns

1. Controller Structure

from frappe_microservice.controller import DocumentController
import frappe

class SalesOrder(DocumentController):
    def validate(self):
        if not self.customer:
            self.throw("Customer is required")
        self.calculate_total()
    
    def before_insert(self):
        if not self.status:
            self.status = 'Draft'
        if not self.transaction_date:
            self.transaction_date = frappe.utils.today()
    
    def after_insert(self):
        self.send_order_notification()
    
    def calculate_total(self):
        self.grand_total = sum(item.amount for item in self.items) if self.items else 0

2. Register Controller

from frappe_microservice.controller import setup_controllers

app = create_microservice("my-service")
setup_controllers(app, controllers_directory="./controllers")

3. Lifecycle Methods

Available: before_validate, validate, before_insert, after_insert, before_update, after_update, before_save, after_save, before_delete, on_trash, on_cancel, on_submit

4. Helper Methods

self.throw(message) - Raise validation error
self.get(field, default=None) - Get field value
self.set(field, value) - Set field value
self.has_value_changed(fieldname) - Check if changed
self.get_value_before_save(fieldname) - Get old value

Key Patterns

Validation: Use validate() for business rules
Defaults: Set in before_insert()
Notifications: Send in after_insert() or after_update()
Calculations: Create reusable methods
Error Handling: Use self.throw() for validation errors

File Naming

File: sales_order.py → Class: SalesOrder → DocType: Sales Order

Remember: This skill is model-invoked. Claude will use it autonomously when detecting controller development needs.

frappe-controller