Allow for Signal.signal choices to be configured

dbmail/defaults.py

@@ -135,5 +135,14 @@ def get_settings(key, default):
     'DB_MAILER_MODEL_SUBSCRIPTION_DATA_FIELD', 'dbmail.fields.DataTextField')
 APNS_PROVIDER_DEFAULT_ACTION = get_settings(
     'DB_MAILER_APNS_PROVIDER_DEFAULT_ACTION', 'Show')
+_SIGNALS = [
+    ('django.db.models.signals.pre_save', 'pre_save'),
+    ('django.db.models.signals.post_save', 'post_save'),
+    ('django.db.models.signals.pre_delete', 'pre_delete'),
+    ('django.db.models.signals.post_delete', 'post_delete'),
+    ('django.db.models.signals.m2m_changed', 'm2m_changed'),
+]
+SIGNAL_CHOICES = get_settings(
+    'DB_MAILER_SIGNAL_CHOICES', _SIGNALS)
 
 DEBUG = settings.DEBUG and get_settings('DB_MAILER_DEBUG', False)

dbmail/migrations/0015_dynamic_signals.py

@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.3 on 2017-08-01 12:06
+from __future__ import unicode_literals
+
+from dbmail.defaults import SIGNAL_CHOICES, _SIGNALS
+from django.db import migrations, models
+
+def make_signals_dynamic(apps, schema_editor):
+    Signal = apps.get_model('dbmail', 'Signal')
+    for module_path, signal_name in _SIGNALS:
+        Signal.objects.filter(signal=signal_name).update(signal=module_path)
+
+def make_signals_undynamic(apps, schema_editor):
+    Signal = apps.get_model('dbmail', 'Signal')
+    for module_path, signal_name in _SIGNALS:
+        Signal.objects.filter(signal=module_path).update(signal=signal_name)
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('dbmail', '0014_auto_20170801_1206'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='signal',
+            name='signal',
+            field=models.CharField(default=b'django.db.models.signals.post_save', max_length=255, verbose_name='Signal', choices=list(SIGNAL_CHOICES))
+        ),
+        migrations.RunPython(make_signals_dynamic, make_signals_undynamic)
+    ]

dbmail/models.py

@@ -19,7 +19,8 @@
     PRIORITY_STEPS, UPLOAD_TO, DEFAULT_CATEGORY, AUTH_USER_MODEL,
     DEFAULT_FROM_EMAIL, DEFAULT_PRIORITY, CACHE_TTL,
     BACKEND, _BACKEND, BACKENDS_MODEL_CHOICES, MODEL_HTMLFIELD,
-    MODEL_SUBSCRIPTION_DATA_FIELD, SORTED_BACKEND_CHOICES, TRACK_USE_GEOIP2
+    MODEL_SUBSCRIPTION_DATA_FIELD, SORTED_BACKEND_CHOICES, TRACK_USE_GEOIP2,
+    SIGNAL_CHOICES
 )
 
 from dbmail import initial_signals, import_by_string
@@ -497,19 +498,13 @@ class Meta:
 
 @python_2_unicode_compatible
 class Signal(models.Model):
-    SIGNALS = (
-        'pre_save',
-        'post_save',
-        'pre_delete',
-        'post_delete',
-        'm2m_changed',
-    )
+    SIGNALS = SIGNAL_CHOICES
     name = models.CharField(_('Name'), max_length=100)
     model = models.ForeignKey(
         'contenttypes.ContentType', verbose_name=_('Model'))
     signal = models.CharField(
-        _('Signal'), choices=zip(SIGNALS, SIGNALS),
-        max_length=15, default='post_save')
+        _('Signal'), choices=SIGNALS,
+        max_length=255, default='post_save')
     template = models.ForeignKey(MailTemplate, verbose_name=_('Template'))
     group = models.ForeignKey(
         MailGroup, verbose_name=_('Email group'), blank=True, null=True,

dbmail/signals.py

@@ -9,6 +9,7 @@
 from django.db.models import signals
 from django import dispatch
 
+from dbmail import import_by_string
 from dbmail.defaults import (
     SIGNALS_QUEUE, SIGNALS_MAIL_QUEUE, SIGNAL_DEFERRED_DISPATCHER,
     ENABLE_USERS, SEND_RETRY, SEND_RETRY_DELAY
@@ -160,7 +161,7 @@ def signal_receiver(sender, **kwargs):
 
 def initial_signals():
     for signal in Signal.objects.filter(is_active=True):
-        def_signal = getattr(signals, signal.signal)
+        def_signal = import_by_string(signal.signal)
         def_signal.connect(
             signal_receiver, sender=signal.model.model_class(),
             dispatch_uid=signal.model.name