Hi,

Some of the changes in odoo 15 is,

• t-raw QWeb directives are replaced by t-out/t-esc ones, with the optional Python tool markupsafe.Markup for escaping HTML content in server side. HTML fields apply directly the markup when used on QWeb. See https://github.com/odoo/odoo/commit/01875541b1a8131cb, https://github.com/odoo/odoo/pull/70004 and https://github.com/odoo/odoo/pull/70004 for more details.

• The access to ir.model* objects has been removed, so you need to use sudo, or use the existing methods for getting usual data. See https://github.com/odoo/odoo/pull/69120 for more info.

• Jinja syntax in mail templates has been replaced by 2 languages:

  • Qweb for the body of the mail template.
  • inline_template, which is similar to Jinja, but with expressions enclosed by {{ and }} instead of ${ and }. It's used in fields like subject, email_from, email_to, etc.

  More info and examples of replacing at https://github.com/odoo/odoo/pull/77074

• If you migrate some .js file to an ES module (they start with /** @odoo-module **/), rename the file to finish with .esm.js (rename also the assets) to enable ESLint compatibility.

• Assets are now directly declared in the manifest. You should move .js and .scss links from templates to __manifest__.py file. They should be placed under "assets" key with the following structure:

  "assets": {
     "web.assets_backend": ["path to .js or css, like /module_name/static/src/...",...],
     "web.assets_qweb": ["path to .xml, like /module_name/static/src/...",...],
     "...": [...],
  },
  

  Notice that there is no more "qweb" key in __manifest__.py. Instead of it, you must link all qweb .xml in web.assets_qweb bundle, as shown above.

  The path to the files is now relative to the root folder, not the module folder.

  Illustrative example: https://github.com/OCA/credit-control/pull/154/commits/c2349c52dc5385f46c94bfa8fc0db2381b251fc8

  You can use globs as well for not having to declare each individual file.

• Replace SavepointCase by TransactionCase in tests, as they are now the same. The old one still exists as an alias, but a warning will arise, and next version will remove such alias. More info at https://github.com/odoo/odoo/pull/62031

• If you write a hook or any code that requires to create a new environment, there's no need of using the with Environment.manage(): context statement anymore.

Link:  https://github.com/OCA/maintainer-tools/wiki/Migration-to-version-15.0

Thanks

Hello Glenn, you know, I do also did some research on this, and this is something I do always lack at the official documentation. There should be Chapter -> "Upgrading custom module", but still it is just a dream.

From my side - generally there is a good documentation of new functionality over here:
https://www.odoo.com/documentation/15.0/developer.html

But as usual, no pointing out the differences scoped in one place. But, there is a hope.
I have found recently this site (codingdodo.com):
https://codingdodo.com/tag/odoo-15/

There are so far 3 Odoo 15 posts.. But very very well explained.. The most "step by step" explanation I have found so far in the net. There is probably also a post you would find very very helpful.

Hope this will help you.