Add user mailer backends support. GitLab issue #286.

Add support for creating dynamic forms.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/mailer/models.py

@@ -1,8 +1,11 @@
 from __future__ import unicode_literals
 
+import json
 import logging
 
+from django.core import mail
 from django.db import models
+from django.utils.module_loading import import_string
 from django.utils.translation import ugettext_lazy as _
 
 logger = logging.getLogger(__name__)
@@ -21,3 +24,110 @@ class LogEntry(models.Model):
         ordering = ('-datetime',)
         verbose_name = _('Log entry')
         verbose_name_plural = _('Log entries')
+
+
+class UserMailer(models.Model):
+    label = models.CharField(
+        max_length=32, unique=True, verbose_name=_('Label')
+    )
+    default = models.BooleanField(
+        default=True, help_text=_(
+            'If default, this mailing profile will be pre-selected on the '
+            'document mailing form.'
+        ), verbose_name=_('Default')
+    )
+    enabled = models.BooleanField(default=True, verbose_name=_('Enabled'))
+    backend_path = models.CharField(
+        max_length=128,
+        help_text=_('The dotted Python path to the backend class.'),
+        verbose_name=_('Backend path')
+    )
+    backend_data = models.TextField(
+        blank=True, verbose_name=_('Backend data')
+    )
+
+    class Meta:
+        ordering = ('label',)
+        verbose_name = _('User mailer')
+        verbose_name_plural = _('User mailers')
+
+    def __str__(self):
+        return self.label
+
+    def save(self, *args, **kwargs):
+        if self.default:
+            UserMailer.objects.select_for_update().exclude(pk=self.pk).update(
+                default=False
+            )
+
+        return super(UserMailer, self).save(*args, **kwargs)
+
+    def backend_label(self):
+        return self.get_backend().label
+
+    def get_backend(self):
+        return import_string(self.backend_path)
+
+    def get_connection(self):
+        return mail.get_connection(
+            backend=self.get_backend().class_path, **self.loads()
+        )
+
+    def loads(self):
+        return json.loads(self.backend_data)
+
+    def dumps(self, data):
+        self.backend_data = json.dumps(data)
+        self.save()
+
+    def send(self, **kwargs):
+        """
+        https://docs.djangoproject.com/en/1.11/topics/email
+        #django.core.mail.EmailMessage
+        subject: The subject line of the email.
+        body: The body text. This should be a plain text message.
+        from_email: The sender's address. Both fred@example.com and Fred
+        <fred@example.com> forms are legal. If omitted,
+        the DEFAULT_FROM_EMAIL setting is used.
+        to: A list or tuple of recipient addresses.
+        bcc: A list or tuple of addresses used in the "Bcc" header when
+        sending the email.
+        connection: An email backend instance. Use this parameter if you want
+        to use the same connection for multiple messages. If omitted, a new
+        connection is created when send() is called.
+        attachments: A list of attachments to put on the message. These can be
+        either email.MIMEBase.MIMEBase instances, or (filename, content,
+        mimetype) triples.
+        headers: A dictionary of extra headers to put on the message. The
+        keys are the header name, values are the header values. It's up to
+        the caller to ensure header names and values are in the correct
+        format for an email message. The corresponding attribute is
+        extra_headers.
+        cc: A list or tuple of recipient addresses used in the "Cc"
+        header when sending the email.
+        reply_to: A list or tuple of recipient addresses used in the
+        "Reply-To" header when sending the email.
+        """
+        with self.get_connection() as connection:
+            mail.EmailMessage(connection=connection, **kwargs).send()
+
+    def test(self, to):
+        self.send(to=to, subject=_('Test email from Mayan EDMS'))
+
+
+class UserMailerLogEntry(models.Model):
+    user_mailer = models.ForeignKey(
+        UserMailer, related_name='error_log', verbose_name=_('User mailer')
+    )
+    datetime = models.DateTimeField(
+        auto_now_add=True, editable=False, verbose_name=_('Date time')
+    )
+    message = models.TextField(
+        blank=True, editable=False, verbose_name=_('Message')
+    )
+
+    class Meta:
+        get_latest_by = 'datetime'
+        ordering = ('-datetime',)
+        verbose_name = _('User mailer log entry')
+        verbose_name_plural = _('User mailer log entries')