[FIX] differed the send of the ticket, since it can cause crash and wkhtmltopdf deadlock, clicking on the button in the pos just tell the system to print the ticket later

beesdoo_pos/__openerp__.py

@@ -26,7 +26,8 @@
     'data': [
         'security/ir.model.access.csv',
         'views/beesdoo_pos.xml',
-        'data/email.xml'
+        'data/email.xml',
+        'data/cron.xml',
     ],
     'qweb': ['static/src/xml/templates.xml'],
     # only loaded in demonstration mode

beesdoo_pos/data/cron.xml

@@ -0,0 +1,14 @@
+<odoo>
+    <data noupdate="1">
+        <record id="ir_cron_sent_pos_ticket" model="ir.cron">
+            <field name="name">send ticket</field>
+            <field name="interval_number">1</field>
+            <field name="interval_type">minutes</field>
+            <field name="numbercall">-1</field>
+            <field name="doall" eval="False" />
+            <field name="model">pos.order</field>
+            <field name="function">_send_order_cron</field>
+            <field name="args">()</field>
+        </record>
+    </data>
+</odoo>

beesdoo_pos/models/beesdoo_pos.py

@@ -1,5 +1,8 @@
 # -*- coding: utf-8 -*-
 from openerp import models, fields, api, _
+import logging
+
+_logger = logging.getLogger(__name__)
 
 class BeesPOS(models.Model):
     _inherit = 'pos.config'
@@ -29,6 +32,11 @@ class BeescoopPosOrder(models.Model):
 
     _inherit = 'pos.order'
 
+    print_status = fields.Selection([('no_print', 'Do not Print'),
+                                     ('to_print', 'To print'),
+                                     ('printed', 'Printed')],
+                                    default="no_print", string="Print Status")
+
     @api.model
     def send_order(self, receipt_name):
         order = self.search([('pos_reference', '=', receipt_name)])
@@ -36,9 +44,23 @@ class BeescoopPosOrder(models.Model):
             return _('Error: no order found')
         if not order.partner_id.email:
             return _('Cannot send the ticket, no email address found on the client')
+        order.print_status = 'to_print'
+
+        return _("Ticket will be sent")
+
+    @api.model
+    def _send_order_cron(self):
         mail_template = self.env.ref("beesdoo_pos.email_send_ticket")
-        mail_template.send_mail(order.id)
-        return _("Ticket sent")
+        _logger.info("Start to send ticket")
+        for order in self.search([('print_status', '=', 'to_print')]):
+            if not order.partner_id.email:
+                continue
+
+            mail_template.send_mail(order.id, force_send=True)
+            order.print_status = 'printed'
+            #Make sure we commit the change to not send ticket twice
+            self.env.cr.commit()
+
 
 class BeescoopPosPartner(models.Model):
     _inherit = 'res.partner'