[IMP] digest: correctly support studio fields in digest

Studio fields are prefixed by x_studio, not only x_ which are simple custom
fields. This commit update the field name check to correctly include fields
created through studio.

As studio automatically add x_studio as prefix help is updated to tell
users to only use kpi_ as prefix for their digest fields. Result will
be x_studio_kpi_foo and x_studio_kpi_foo_value which are the value digest
needs to run.

This commit is linked to task ID 1887619.

addons/digest/models/digest.py

@@ -51,7 +51,7 @@ class Digest(models.Model):
         for digest in self:
             kpis_values_fields = []
             for field_name, field in digest._fields.items():
-                if field.type == 'boolean' and (field_name.startswith('kpi_') or field_name.startswith('x_kpi_')) and digest[field_name]:
+                if field.type == 'boolean' and field_name.startswith(('kpi_', 'x_kpi_', 'x_studio_kpi_')) and digest[field_name]:
                     kpis_values_fields += [field_name + '_value']
             digest.available_fields = ', '.join(kpis_values_fields)
 
@@ -112,7 +112,7 @@ class Digest(models.Model):
             previous_digest = self.with_context(start_date=tf[1][0], end_date=tf[1][1], company=company).sudo(user.id)
             kpis = {}
             for field_name, field in self._fields.items():
-                if field.type == 'boolean' and (field_name.startswith('kpi_') or field_name.startswith('x_kpi_')) and self[field_name]:
+                if field.type == 'boolean' and field_name.startswith(('kpi_', 'x_kpi_', 'x_studio_kpi_')) and self[field_name]:
 
                     try:
                         compute_value = digest[field_name + '_value']

addons/digest/views/digest_views.xml

@@ -76,12 +76,12 @@
                                             </li>
                                             <li>
                                                 first create a boolean field called
-                                                <code>x_kpi_myfield</code>
+                                                <code>kpi_myfield</code>
                                                 and display it in the KPI's tab;
                                             </li>
                                             <li>
                                                 then create a computed field called
-                                                <code>x_kpi_myfield_value</code>
+                                                <code>kpi_myfield_value</code>
                                                 that will compute your customized KPI.
                                             </li>
                                         </ul>