[IMP] mail: add an option to preview templates in a specific language

Purpose: allow to check email preview in a specific language in order to see
the result in a given translation context.

Specifications

  * added preview_lang field to change language of template
  * set default language from the template by evaluating expression if lang field of template is set,

This commit is related to task ID: 30245

closes odoo/odoo#19165

Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>

addons/mail/models/mail_template.py

@@ -360,13 +360,18 @@ class MailTemplate(models.Model):
             return results
         self.ensure_one()
 
-        langs = self._render_template(self.lang, self.model, res_ids)
-        for res_id, lang in langs.items():
-            if lang:
-                template = self.with_context(lang=lang)
-            else:
-                template = self
-            results[res_id] = template
+        if self.env.context.get('template_preview_lang'):
+            lang = self.env.context.get('template_preview_lang')
+            for res_id in res_ids:
+                results[res_id] = self.with_context(lang=lang)
+        else:
+            langs = self._render_template(self.lang, self.model, res_ids)
+            for res_id, lang in langs.items():
+                if lang:
+                    template = self.with_context(lang=lang)
+                else:
+                    template = self
+                results[res_id] = template
 
         return multi_mode and results or results[res_ids[0]]
 

addons/mail/wizard/email_template_preview.py

@@ -21,22 +21,30 @@ class TemplatePreview(models.TransientModel):
         records |= records.browse(default_res_id)
         return records.name_get()
 
+    @api.model
+    def _get_languages(self):
+        return self.env['res.lang'].get_installed()
+
     @api.model
     def default_get(self, fields):
         result = super(TemplatePreview, self).default_get(fields)
 
+        template = self._context.get('template_id') and self.env['mail.template'].browse(self._context['template_id']) or False
         if 'res_id' in fields and not result.get('res_id'):
             records = self._get_records()
             result['res_id'] = records and records[0][0] or False  # select first record as a Default
-        if self._context.get('template_id') and 'model_id' in fields and not result.get('model_id'):
-            result['model_id'] = self.env['mail.template'].browse(self._context['template_id']).model_id.id
+        if template and 'model_id' in fields and not result.get('model_id'):
+            result['model_id'] = template.model_id.id
+        if template and 'preview_lang' in fields and not result.get('preview_lang') and result.get('res_id'):
+            result['preview_lang'] = template.lang and template.generate_email(result['res_id'], ['lang'])['lang'] or template._context.get('lang')
         return result
 
     res_id = fields.Selection(_get_records, 'Sample Document')
     partner_ids = fields.Many2many('res.partner', string='Recipients')
     attachment_ids = fields.Many2many(string='Attachments', store=False)
+    preview_lang = fields.Selection(_get_languages, string='Template Preview Language')
 
-    @api.onchange('res_id')
+    @api.onchange('res_id', 'preview_lang')
     @api.multi
     def on_change_res_id(self):
         if not self.res_id:
@@ -45,6 +53,6 @@ class TemplatePreview(models.TransientModel):
         if self._context.get('template_id'):
             template = self.env['mail.template'].browse(self._context['template_id'])
             self.name = template.name
-            mail_values = template.generate_email(self.res_id)
+            mail_values = template.with_context(template_preview_lang=self.preview_lang).generate_email(self.res_id)
         for field in ['email_from', 'email_to', 'email_cc', 'reply_to', 'subject', 'body_html', 'partner_to', 'partner_ids', 'attachment_ids']:
             setattr(self, field, mail_values.get(field, False))

addons/mail/wizard/email_template_preview_view.xml

@@ -11,6 +11,7 @@
                     <h3>Preview of <field name="name" readonly="1" nolabel="1" class="oe_inline"/></h3>
                     Choose an example <field name="model_id" class="oe_inline" readonly="1"/> record:
                     <field name="res_id" class="oe_inline" style="margin-left: 8px;"/>
+                    <p>Choose a language: <field name="preview_lang" class="oe_inline ml8"/></p>
                     <group>
                         <field name="subject" readonly="1"/>
                         <field name="email_from" readonly="1"