social/mail_sendgrid/wizards/email_template_preview.py

# -*- coding: utf-8 -*-
# Copyright 2015-2017 Compassion CH (http://www.compassion.ch)
# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).

from odoo import models, api


class EmailTemplatePreview(models.TransientModel):
    """ Put the preview inside sendgrid template """
    _inherit = 'email_template.preview'

    @api.onchange('res_id')
    @api.multi
    def on_change_res_id(self):
        result = super(EmailTemplatePreview, self).on_change_res_id()
        body_html = self.body_html
        template_id = self.env.context.get('template_id')
        template = self.env['mail.template'].browse(template_id)
        sendgrid_template = template.sendgrid_localized_template
        if sendgrid_template:
            self.body_html = sendgrid_template.html_content.replace(
                '<%body%>', body_html)
        return result