[REF] website_slides: move from onchange / default to stored editable computed field

PURPOSE

Try to move from onchange / default_get to stored editable computed fields.
Behavior should be the same (computed or set by user), with support of
create / write / onchange field update without additional code.

SPECIFICATIONS

Update classic fields updated in some cases by onchange and/or default methods
by fields with store=True, readonly=False. It means their value comes either
from manual user input, either from trigger based computation.

Remove onchange and default_get when possible, leading to an unique computation
method and clearing fields definition.

Also clean some fields definition inconsistencies, notably required fields
that should instead be correctly computed or default that have no real meaning.

SPECIFICATIONS: WIZARD CLEANING

Remove email_from and author_id fieles defined on invite wizard. Those are
not used in this wizard (not available in view) and default value is to use
current user. We can simplify this wizard model by removing them.

LINKS

Task ID : 2229048
PR : #49040

Related: odoo/upgrade#1198
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>

addons/website_slides/__manifest__.py

 # -*- coding: utf-8 -*-
 {
     'name': 'eLearning',
-    'version': '2.0',
+    'version': '2.1',
     'sequence': 145,
     'summary': 'Manage and publish an eLearning platform',
     'website': 'https://www.odoo.com/page/slides',

addons/website_slides/wizard/slide_channel_invite.py

@@ -17,40 +17,25 @@ class SlideChannelInvite(models.TransientModel):
     _name = 'slide.channel.invite'
     _description = 'Channel Invitation Wizard'
 
-    @api.model
-    def _default_email_from(self):
-        if self.env.user.email:
-            return formataddr((self.env.user.name, self.env.user.email))
-        raise UserError(_("Unable to post message, please configure the sender's email address."))
-
-    @api.model
-    def _default_author_id(self):
-        return self.env.user.partner_id
-
     # composer content
-    subject = fields.Char('Subject')
-    body = fields.Html('Contents', default='', sanitize_style=True)
+    subject = fields.Char('Subject', compute='_compute_template_values', readonly=False, store=True)
+    body = fields.Html('Contents', default='', sanitize_style=True, compute='_compute_template_values', readonly=False, store=True)
     attachment_ids = fields.Many2many('ir.attachment', string='Attachments')
     template_id = fields.Many2one(
         'mail.template', 'Use template',
         domain="[('model', '=', 'slide.channel.partner')]")
-    # origin
-    email_from = fields.Char('From', default=_default_email_from)
-    author_id = fields.Many2one(
-        'res.partner', 'Author',
-        ondelete='set null', default=_default_author_id)
     # recipients
     partner_ids = fields.Many2many('res.partner', string='Recipients')
     # slide channel
     channel_id = fields.Many2one('slide.channel', string='Slide channel', required=True)
     channel_url = fields.Char(related="channel_id.website_url", readonly=True)
 
-    @api.onchange('template_id')
-    def _onchange_template_id(self):
-        """ Make the 'subject' and 'body' field match the selected template_id """
-        if self.template_id:
-            self.subject = self.template_id.subject
-            self.body = self.template_id.body_html
+    @api.depends('template_id')
+    def _compute_template_values(self):
+        for invite in self:
+            if invite.template_id:
+                invite.subject = invite.template_id.subject
+                invite.body = invite.template_id.body_html
 
     @api.onchange('partner_ids')
     def _onchange_partner_ids(self):
@@ -81,6 +66,9 @@ class SlideChannelInvite(models.TransientModel):
             email(s), rendering any template patterns on the fly if needed """
         self.ensure_one()
 
+        if not self.env.user.email:
+            raise UserError(_("Unable to post message, please configure the sender's email address."))
+
         mail_values = []
         for partner_id in self.partner_ids:
             slide_channel_partner = self.channel_id._action_add_members(partner_id)
@@ -99,8 +87,8 @@ class SlideChannelInvite(models.TransientModel):
         body = self.env['mail.render.mixin']._render_template(self.body, 'slide.channel.partner', slide_channel_partner.ids, post_process=True)[slide_channel_partner.id]
         # post the message
         mail_values = {
-            'email_from': self.email_from,
-            'author_id': self.author_id.id,
+            'email_from': self.env.user.email_formatted,
+            'author_id': self.env.user.partner_id.id,
             'model': None,
             'res_id': None,
             'subject': subject,