Extending openwisp-notifications
Note
This page is for developers who want to customize or extend OpenWISP Notifications, whether for bug fixes, new features, or contributions.
For user guides and general information, please see:
One of the core values of the OpenWISP project is Software Reusability, for this reason OpenWISP Notifications provides a set of base classes which can be imported, extended and reused to create derivative apps.
In order to implement your custom version of openwisp-notifications, you need to perform the steps described in the rest of this section.
When in doubt, the code in test project and sample_notifications will guide you in the correct direction: just replicate and adapt that code to get a basic derivative of openwisp-notifications working.
Important
If you plan on using a customized version of this module, we suggest to start with it since the beginning, because migrating your data from the default module to your extended version may be time consuming.
1. Initialize your custom module
The first thing you need to do in order to extend openwisp-notifications is create a new django app which will contain your custom version of that openwisp-notifications app.
A django app is nothing more than a python package (a directory
of python scripts), in the following examples we'll call this django app
as mynotifications but you can name it how you want:
django-admin startapp mynotifications
Keep in mind that the command mentioned above must be called from a directory which is available in your PYTHON_PATH so that you can then import the result into your project.
Now you need to add mynotifications to INSTALLED_APPS in your
settings.py, ensuring also that openwisp_notifications has been
removed:
INSTALLED_APPS = [
# ... other apps ...
# 'openwisp_notifications', <-- comment out or delete this line
"mynotifications",
]
For more information about how to work with django projects and django apps, please refer to the django documentation.
2. Install openwisp-notifications
Install (and add to the requirement of your project) openwisp-notifications:
pip install -U https://github.com/openwisp/openwisp-notifications/tarball/master
3. Add EXTENDED_APPS
Add the following to your settings.py:
EXTENDED_APPS = ["openwisp_notifications"]
4. Add openwisp_utils.staticfiles.DependencyFinder
Add openwisp_utils.staticfiles.DependencyFinder to
STATICFILES_FINDERS in your settings.py:
STATICFILES_FINDERS = [
"django.contrib.staticfiles.finders.FileSystemFinder",
"django.contrib.staticfiles.finders.AppDirectoriesFinder",
"openwisp_utils.staticfiles.DependencyFinder",
]
5. Add openwisp_utils.loaders.DependencyLoader
Add openwisp_utils.loaders.DependencyLoader to TEMPLATES in your
settings.py:
TEMPLATES = [
{
"BACKEND": "django.template.backends.django.DjangoTemplates",
"OPTIONS": {
"loaders": [
"django.template.loaders.filesystem.Loader",
"django.template.loaders.app_directories.Loader",
"openwisp_utils.loaders.DependencyLoader",
],
"context_processors": [
"django.template.context_processors.debug",
"django.template.context_processors.request",
"django.contrib.auth.context_processors.auth",
"django.contrib.messages.context_processors.messages",
],
},
}
]
6. Inherit the AppConfig class
Please refer to the following files in the sample app of the test project:
For more information regarding the concept of AppConfig please refer
to the "Applications" section in the django documentation.
7. Create your custom models
For the purpose of showing an example, we added a simple "details" field to the models of the sample app in the test project.
You can add fields in a similar way in your models.py file.
Note
If you have questions about using, extending, or developing models, refer to the "Models" section of the Django documentation.
8. Add swapper configurations
Add the following to your settings.py:
# Setting models for swapper module
OPENWISP_NOTIFICATIONS_NOTIFICATION_MODEL = "mynotifications.Notification"
OPENWISP_NOTIFICATIONS_NOTIFICATIONSETTING_MODEL = (
"mynotifications.NotificationSetting"
)
OPENWISP_NOTIFICATIONS_IGNOREOBJECTNOTIFICATION_MODEL = (
"mynotifications.IgnoreObjectNotification"
)
9. Create database migrations
Create and apply database migrations:
./manage.py makemigrations
./manage.py migrate
For more information, refer to the "Migrations" section in the django documentation.
10. Create your custom admin
Refer to the admin.py file of the sample app.
To introduce changes to the admin, you can do it in two main ways which are described below.
Note
For more information regarding how the django admin works, or how it can be customized, please refer to "The django admin site" section in the django documentation.
1. Monkey patching
If the changes you need to add are relatively small, you can resort to monkey patching.
For example:
from openwisp_notifications.admin import NotificationSettingInline
NotificationSettingInline.list_display.insert(1, "my_custom_field")
NotificationSettingInline.ordering = ["-my_custom_field"]
2. Inheriting admin classes
If you need to introduce significant changes and/or you don't want to resort to monkey patching, you can proceed as follows:
from django.contrib import admin
from openwisp_notifications.admin import (
NotificationSettingInline as BaseNotificationSettingInline,
)
from openwisp_notifications.swapper import load_model
NotificationSetting = load_model("NotificationSetting")
admin.site.unregister(NotificationSettingAdmin)
admin.site.unregister(NotificationSettingInline)
@admin.register(NotificationSetting)
class NotificationSettingInline(BaseNotificationSettingInline):
# add your changes here
pass
11. Create root URL configuration
Please refer to the urls.py file in the test project.
For more information about URL configuration in django, please refer to the "URL dispatcher" section in the django documentation.
12. Create root routing configuration
Please refer to the routing.py file in the test project.
For more information about URL configuration in django, please refer to the "Routing" section in the Channels documentation.
13. Create celery.py
Please refer to the celery.py file in the test project.
For more information about the usage of celery in django, please refer to the "First steps with Django" section in the celery documentation.
14. Import Celery Tasks
Add the following in your settings.py to import Celery tasks from
openwisp_notifications app.
CELERY_IMPORTS = ("openwisp_notifications.tasks",)
16. Register Notification Types
You can register notification types as shown in the section for registering notification types.
A reference for registering a notification type is also provided in
sample_notifications/apps.py.
The registered notification type of sample_notifications app is used
for creating notifications when an object of TestApp model is created.
You can use sample_notifications/models.py
as reference for your implementation.
17. Import the automated tests
When developing a custom application based on this module, it's a good idea to import and run the base tests too, so that you can be sure the changes you're introducing are not breaking some of the existing feature of openwisp-notifications.
In case you need to add breaking changes, you can overwrite the tests defined in the base classes to test your own behavior.
See the tests of the sample_notifications to find out how to do this.
Note
Some tests will fail if templatetags and admin/base.html are
not configured properly. See preceding sections to configure them
properly.
Other base classes that can be inherited and extended
The following steps are not required and are intended for more advanced customization.
API views
The API view classes can be extended into other django applications as well. Note that it is not required for extending openwisp-notifications to your app and this change is required only if you plan to make changes to the API views.
Create a view file as done in sample_notifications/views.py
For more information regarding Django REST Framework API views, please refer to the "Generic views" section in the Django REST Framework documentation.
Web Socket Consumers
The Web Socket Consumer classes can be extended into other django applications as well. Note that it is not required for extending openwisp-notifications to your app and this change is required only if you plan to make changes to the consumers.
Create a consumer file as done in sample_notifications/consumers.py
For more information regarding Channels' Consumers, please refer to the "Consumers" section in the Channels documentation.