[ADD] Add a scheduled date mechanism on email templates

And use this new features to send the email template defined in the last commit
on the module installation.

addons/mail/models/mail_mail.py

@@ -1,7 +1,9 @@
 # -*- coding: utf-8 -*-
 
 import base64
+import datetime
 import logging
+
 from email.utils import formataddr
 from urlparse import urljoin
 
@@ -50,6 +52,8 @@ class MailMail(models.Model):
     failure_reason = fields.Text(
         'Failure Reason', readonly=1,
         help="Failure reason. This is usually the exception thrown by the email server, stored to ease the debugging of mailing issues.")
+    scheduled_date = fields.Char('Scheduled Send Date',
+        help="If set, the queue manager will send the email after the date. If not set, the email will be send as soon as possible.")
 
     @api.model
     def create(self, values):
@@ -98,7 +102,11 @@ class MailMail(models.Model):
                                 messages are sent).
         """
         if not self.ids:
-            filters = [('state', '=', 'outgoing')]
+            filters = ['&',
+                       ('state', '=', 'outgoing'),
+                       '|',
+                       ('scheduled_date', '<', datetime.datetime.now()),
+                       ('scheduled_date', '=', False)]
             if 'filters' in self._context:
                 filters.extend(self._context['filters'])
             ids = self.search(filters).ids

addons/mail/models/mail_template.py

@@ -160,6 +160,7 @@ class MailTemplate(models.Model):
                                                   "destination document model (sub-model).")
     null_value = fields.Char('Default Value', help="Optional value to use if the target field is empty")
     copyvalue = fields.Char('Placeholder Expression', help="Final placeholder expression, to be copy-pasted in the desired template field.")
+    scheduled_date = fields.Char('Scheduled Date', help="If set, the queue manager will send the email after the date. If not set, the email will be send as soon as possible. Jinja2 placeholders may be used.")
 
     @api.onchange('model_id')
     def onchange_model_id(self):
@@ -433,7 +434,7 @@ class MailTemplate(models.Model):
             res_ids = [res_ids]
             multi_mode = False
         if fields is None:
-            fields = ['subject', 'body_html', 'email_from', 'email_to', 'partner_to', 'email_cc', 'reply_to']
+            fields = ['subject', 'body_html', 'email_from', 'email_to', 'partner_to', 'email_cc', 'reply_to', 'scheduled_date']
 
         res_ids_to_templates = self.get_email_template_batch(res_ids)
 

addons/mail/views/mail_mail_views.xml

@@ -27,6 +27,7 @@
                             <field name="recipient_ids" widget="many2many_tags"/>
                             <field name="email_cc"/>
                             <field name="reply_to"/>
+                            <field name="scheduled_date"/>
                         </group>
                         <notebook>
                             <page string="Body">

addons/mail/views/mail_template_views.xml

@@ -59,6 +59,7 @@
                                     <field name="reply_to"
                                             placeholder="Preferred reply address"/>
                                     <field name="user_signature" string="Author Signature (mass mail only)"/>
+                                    <field name="scheduled_date" string="Scheduled Send Date"/>
                                 </group>
                             </page>
                             <page string="Advanced Settings">

addons/mail/wizard/email_template_preview_view.xml

@@ -22,6 +22,8 @@
                                 attrs="{'invisible':[('email_cc','=',False)]}"/>
                         <field name="reply_to" readonly="1"
                                 attrs="{'invisible':[('reply_to','=',False)]}"/>
+                        <field name="scheduled_date" readonly="1"
+                                attrs="{'invisible':[('scheduled_date','=',False)]}"/>
                     </group>
                     <field name="body_html" widget="html" readonly="1"
                             nolabel="1" options='{"safe": True}'/>