odoo-approval-workflow

Odoo 17 module — Multi-level approval engine for purchase orders, expenses and custom documents.

Screenshots

Form View	List View	Approval History

Features

• Configurable templates: define N approval levels per document type (Purchase Order, Expense Sheet)
• Smart amount routing: levels automatically selected based on amount_total thresholds
• Flexible approver resolution: Specific User, User Group, Direct Manager, Purchase Manager
• Purchase order interception: overrides button_confirm() — orders above threshold block until approved
• Full audit trail: approval.request.line records every decision with timestamp + comment
• Delegation: approver can delegate to another user (configurable per level)
• Escalation cron: auto-escalates requests past their deadline
• Email notifications: mail template sent to approver at each level
• Odoo Activities: creates mail.mail_activity_data_todo for each pending approver

How it works

PurchaseOrder.button_confirm()
       │
       ├─→ amount_total < threshold? ──→ confirm immediately
       │
       └─→ amount_total >= threshold?
               │
               ▼
       ApprovalRequest.create() + submit()
               │
               ▼
       Level 0 → email approver → activity created
               │
               ▼ (approver clicks Approve)
       Level 1 → email next approver...
               │
               ▼ (all levels done)
       PurchaseOrder._on_approval_granted()
       → super().button_confirm() → PO confirmed

Technical highlights

Area	Implementation
Model override	purchase.order.button_confirm() intercepted with approval gate
Dynamic routing	get_required_levels(amount) — filters levels by min/max amount
Approver resolution	get_approver_for_record() — handles user/group/manager/purchase_manager
Callback pattern	_on_approval_granted() / _on_approval_refused() hooks on source model
State machine	5 states: draft → pending → approved/refused/cancelled
Wizard	approval.action.wizard TransientModel for approve/refuse/delegate
Cron	Daily escalation of overdue requests
Security	ir.model.access.csv — users read-only on templates, write on own requests

Author

Bayane Miguel Singcol — Odoo Developer
GitHub · baymi312@gmail.com