brotherton-erpnext/erpnext/hr/page/organizational_chart/organizational_chart.py

import frappe


@frappe.whitelist()
def get_children(parent=None, company=None, exclude_node=None):
	filters = [['status', '!=', 'Left']]
	if company and company != 'All Companies':
		filters.append(['company', '=', company])

	if parent and company and parent != company:
		filters.append(['reports_to', '=', parent])
	else:
		filters.append(['reports_to', '=', ''])

	if exclude_node:
		filters.append(['name', '!=', exclude_node])

	employees = frappe.get_list('Employee',
		fields=['employee_name as name', 'name as id', 'reports_to', 'image', 'designation as title'],
		filters=filters,
		order_by='name'
	)

	for employee in employees:
		is_expandable = frappe.db.count('Employee', filters={'reports_to': employee.get('id')})
		employee.connections = get_connections(employee.id)
		employee.expandable = 1 if is_expandable else 0

	return employees


def get_connections(employee):
	num_connections = 0

	nodes_to_expand = frappe.get_list('Employee', filters=[
			['reports_to', '=', employee]
		])
	num_connections += len(nodes_to_expand)

	while nodes_to_expand:
		parent = nodes_to_expand.pop(0)
		descendants = frappe.get_list('Employee', filters=[
			['reports_to', '=', parent.name]
		])
		num_connections += len(descendants)
		nodes_to_expand.extend(descendants)

	return num_connections