[IMP] website_sale: Stock Availability banner on shop/product/id view

An availability selection field with 3 values :
- Display nothing
- In stock
- Warning + a warning message that could be something like 'available with
  a variable delay of 15 days

addons/website_sale/models/product.py

@@ -92,6 +92,12 @@ class ProductTemplate(models.Model):
                                       default=lambda self: self._default_website_sequence())
     public_categ_ids = fields.Many2many('product.public.category', string='Website Product Category',
                                         help="Those categories are used to group similar products for e-commerce.")
+    availability = fields.Selection([
+        ('empty', 'Display Nothing'),
+        ('in_stock', 'In Stock'),
+        ('warning', 'Warning'),
+    ], "Availability", default='empty', help="This field is used to display a availability banner with a message on the ecommerce")
+    availability_warning = fields.Text("Availability Warning", translate=True)
 
     def _default_website_sequence(self):
         min_sequence = self.sudo().search([], order='website_sequence', limit=1).website_sequence

addons/website_sale/views/templates.xml

@@ -389,6 +389,16 @@
 
                 </form>
 
+                <hr/>
+                <div t-if="product.availability == 'in_stock'" class="alert alert-success">
+                  <span class="fa fa-check"/>
+                  <span>In Stock</span>
+                </div>
+                <div t-if="product.availability == 'warning'" class="alert alert-warning">
+                  <span class="fa fa-warning"/>
+                  <span t-field="product.availability_warning"/>
+                </div>
+
                 <hr t-if="product.description_sale"/>
                 <div><p t-field="product.description_sale" class="text-muted"/></div>
                 <hr/>

addons/website_sale/views/views.xml

@@ -23,6 +23,8 @@
                     <field name="public_categ_ids" widget="many2many_tags" string="Website Categories"/>
                     <field name="alternative_product_ids" widget="many2many_tags"/>
                     <field name="accessory_product_ids" widget="many2many_tags"/>
+                    <field name="availability" widget="selection"/>
+                    <field name="availability_warning" attrs="{'invisible': [('availability', '!=', 'warning')]}"/>
                     <field name="website_style_ids" widget="many2many_tags" groups="base.group_no_one"/>
                 </group>
             </group>