# Onchange Helper

This is a technical module. Its goal is to ease the play of onchange method directly called from Python code.

Table of contents

- Usage
- Known issues / Roadmap
- Bug Tracker
- Credits
  - Authors
  - Contributors
  - Maintainers

# Usage

To use this module, you need to:

- depend on this module
- call yourmodel.play_onchanges(values, [‘field’])

Example if you want to create a sale order and you want to get the values relative to partner_id field (as if you fill the field from UI)

> vals = {‘partner_id’: 1}

> vals = self.env[‘sale.order’].play_onchanges(vals, [‘partner_id’])

Then, vals will be updated with partner_invoice_id, partner_shipping_id, pricelist_id, etc…

Default values will be used to process onchange methods, if respective fields are not set in vals. You can get them if you pass fields name in the list of fields.

> vals = {‘partner_id’: 1}

> vals = self.env[‘sale.order’].play_onchanges(vals, [‘partner_id’, ‘date_order’])

vals will contain, in addition to the changed values, the default value for date_order

You can also use it on existing record for example:

> vals = {‘partner_shipping_id’: 1}

> vals = sale.play_onchanges(vals, [‘partner_shipping_id’])

Then the onchange will be played with the vals passed and the existing vals of the sale. vals will be updated with partner_invoice_id, pricelist_id, etc..

Behind the scene, play_onchanges will execute all the methods registered for the list of changed fields, so you do not have to call manually each onchange. To avoid performance issue when the method is called on a record, the record will be transformed into a memory record before calling the registered methods to avoid to trigger SQL updates command when values are assigned to the record by the onchange

Notes:

- Order in onchange_fields is very important as onchanges methods will be played in that order.
- If you use memory object in vals, be award that onchange method in base model call self.invalidate_cache() that reset it.

# Known issues / Roadmap

Note that onchanges tend to disappear due to the introduction of ‘computed stored readonly False fields’ in most cases. When migrating, it is best to prefer changing it to that way instead of using this module.

# Bug Tracker

Bugs are tracked on GitHub Issues. In case of trouble, please check there if your issue has already been reported. If you spotted it first, help us to smash it by providing a detailed and welcomed feedback.

Do not contact contributors directly about support or help with technical issues.

# Credits

## Authors

- Akretion
- Camptocamp

## Contributors

- Guewen Baconnier <guewen.baconnier@camptocamp.com>
- Florian da Costa <florian.dacosta@akretion.com>
- Andrea Stirpe <a.stirpe@onestein.nl>
- Souheil Bejaoui <souheil.bejaoui@acsone.eu>
- Kevin Khao <kevin.khao@akretion.com>

## Maintainers

This module is maintained by the OCA.

OCA, or the Odoo Community Association, is a nonprofit organization whose mission is to support the collaborative development of Odoo features and promote its widespread use.

This module is part of the OCA/server-tools project on GitHub.

You are welcome to contribute. To learn how please visit https://odoo-community.org/page/Contribute.