blechreiz-website/simpleforum/models.py

from django.db import models
from django.utils.translation import ugettext as _
from django.contrib.auth.models import User
from django.db.models.signals import post_save
from django.dispatch import receiver
from django.core.mail import EmailMultiAlternatives
from musicians.models import Musician
from django.template.loader import get_template
from django.template import Context


class Message(models.Model):
    titel = models.CharField(max_length=100, verbose_name=_("titel"))
    text = models.TextField(blank=False, verbose_name=_("text"))

    creation_time = models.DateTimeField(verbose_name=_("creation_time"))
    author = models.ForeignKey(User, verbose_name=_("Author"), on_delete=models.PROTECT)

    def __unicode__(self):
        return self.author.username + " : " + self.titel


@receiver(post_save, sender=Message)
def my_handler(sender, instance, created, **kwargs):
    if not created:
        return

    receivers = [m.user.email for m in Musician.objects.all()]

    subject = "Blechreiz Forum: " + instance.titel
    from_email = 'forum@blechreiz.com'

    c = {'messages': Message.objects.all().order_by('-creation_time')[:10]}

    text_template = get_template("simpleforum/mail.txt")
    # html_template = get_template( "simpleforum/mail.html" )

    text_content = text_template.render(Context(c))
    # html_content = html_template.render( Context(c) )

    msg = EmailMultiAlternatives(subject, text_content, from_email, receivers)
    # msg.attach_alternative( html_content, "text/html" )
    msg.send()