Extending OpenWISP Network Topology

Note

This page is for developers who want to customize or extend OpenWISP Network Topology, 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-network-topology 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-network-topology, you need to perform the steps described in this section.

When in doubt, the code in the test project and the sample app will serve you as source of truth: just replicate and adapt that code to get a basic derivative of openwisp-network-topology 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 is to create a new django app which will contain your custom version of openwisp-network-topology.

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 sample_network_topology, but you can name it how you want:

django-admin startapp sample_network_topology

If you use the integration with openwisp-controller, you may want to extend also the integration app if you need:

django-admin startapp sample_integration_device

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 sample_network_topology to INSTALLED_APPS in your settings.py, ensuring also that openwisp_network_topology has been removed:

INSTALLED_APPS = [
    # ... other apps ...
    "openwisp_utils.admin_theme",
    # all-auth
    "django.contrib.sites",
    "openwisp_users.accounts",
    "allauth",
    "allauth.account",
    "allauth.socialaccount",
    # (optional) openwisp_controller - required only if you are using the integration app
    "openwisp_controller.pki",
    "openwisp_controller.config",
    "reversion",
    "sortedm2m",
    # network topology
    # 'sample_network_topology' <-- uncomment and replace with your app-name here
    # (optional) required only if you need to extend the integration app
    # 'sample_integration_device' <-- uncomment and replace with your integration-app-name here
    "openwisp_users",
    # admin
    "django.contrib.admin",
    # rest framework
    "rest_framework",
]

For more information about how to work with django projects and django apps, please refer to the django documentation.

2. Install `openwisp-network-topology`

Install (and add to the requirement of your project) openwisp-network-topology:

pip install openwisp-network-topology

3. Add `EXTENDED_APPS`

Add the following to your settings.py:

EXTENDED_APPS = ("openwisp_network_topology",)

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 the integration with openwisp-controller, see:

You have to replicate and adapt that code in your project.

For more information regarding the concept of AppConfig please refer to the "Applications" section in the django documentation.

7. Create your Custom Models 

Please refer to sample_app models file use in the test project.

You have to replicate and adapt that code in your project.

Note

If you have questions about using, extending, or developing models, refer to the "Models" section of the Django documentation.

8. Add Swapper Configurations 

Once you have created the models, add the following to your settings.py:

# Setting models for swapper module
TOPOLOGY_LINK_MODEL = "sample_network_topology.Link"
TOPOLOGY_NODE_MODEL = "sample_network_topology.Node"
TOPOLOGY_SNAPSHOT_MODEL = "sample_network_topology.Snapshot"
TOPOLOGY_TOPOLOGY_MODEL = "sample_network_topology.Topology"
# if you use the integration with OpenWISP Controller and/or OpenWISP Monitoring
TOPOLOGY_DEVICE_DEVICENODE_MODEL = "sample_integration_device.DeviceNode"
TOPOLOGY_DEVICE_WIFIMESH_MODEL = "sample_integration_device.WifiMesh"

Substitute sample_network_topology with the name you chose in step 1.

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 the 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_network_topology.admin import (
    TopologyAdmin,
    LinkAdmin,
    NodeAdmin,
)

# TopologyAdmin.list_display.insert(1, 'my_custom_field') <-- your custom change example
# LinkAdmin.list_display.insert(1, 'my_custom_field') <-- your custom change example
# NodeAdmin.list_display.insert(1, 'my_custom_field') <-- your custom change example

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 swapper import load_model

from openwisp_network_topology.admin import (
    TopologyAdmin as BaseTopologyAdmin,
    LinkAdmin as BaseLinkAdmin,
    NodeAdmin as BaseNodeAdmin,
)

Node = load_model("topology", "Node")
Link = load_model("topology", "Link")
Topology = load_model("topology", "Topology")

admin.site.unregister(Topology)
admin.site.unregister(Link)
admin.site.unregister(Node)


@admin.register(Topology, TopologyAdmin)
class TopologyAdmin(BaseTopologyAdmin):
    # add your changes here
    pass


@admin.register(Link, LinkAdmin)
class LinkAdmin(BaseLinkAdmin):
    # add your changes here
    pass


@admin.register(Node, NodeAdmin)
class NodeAdmin(BaseNodeAdmin):
    # add your changes here
    pass

11. Create Root URL Configuration 

The following can be used to register all the URLs in your: urls.py.

Please read and replicate according to your project needs:

# If you've extended visualizer views (discussed below).
# Import visualizer views & function to add it.
# from openwisp_network_topology.utils import get_visualizer_urls
# from .sample_network_topology.visualizer import views

urlpatterns = [
    # If you've extended visualizer views (discussed below).
    # Add visualizer views in urls.py
    # path('topology/', include(get_visualizer_urls(views))),
    path("", include("openwisp_network_topology.urls")),
    path("admin/", admin.site.urls),
]

For more information about URL configuration in django, please refer to the "URL dispatcher" section in the django documentation.

12. Setup API URLs 

You need to create a file api/urls.py (the name & path of the file must match) inside your app, which contains the following:

from openwisp_network_topology.api import views

# When you want to modify views, please change views location
# from . import views
from openwisp_network_topology.utils import get_api_urls

urlpatterns = get_api_urls(views)

13. Extending Management Commands 

To extend the management commands, create sample_network_topology/management/commands directory and two files in it:

14. 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 features of openwisp-network-topology.

Refer to the tests.py file of the sample app.

In case you need to add breaking changes, you can overwrite the tests defined in the base classes to test your own behavior.

For testing you also need to extend the fixtures, you can copy the file openwisp_network_topology/fixtures/test_users.json in your sample app's fixtures/ directory.

Now, you can then run tests with:

# the --parallel flag is optional
./manage.py test --parallel sample_network_topology

Substitute sample_network_topology with the name you chose in step 1.

For more information about automated tests in django, please refer to "Testing in Django".

Extending OpenWISP Network Topology

1. Initialize your Custom Module 

2. Install `openwisp-network-topology`

3. Add `EXTENDED_APPS`

4. Add `openwisp_utils.staticfiles.DependencyFinder`

5. Add `openwisp_utils.loaders.DependencyLoader`

6. Inherit the AppConfig Class 

7. Create your Custom Models 

8. Add Swapper Configurations 

9. Create Database Migrations 

10. Create the Admin 

1. Monkey Patching 

2. Inheriting Admin Classes 

11. Create Root URL Configuration 

12. Setup API URLs 

13. Extending Management Commands 

14. Import the Automated Tests 

Other Base Classes that can be Inherited and Extended 

1. Extending API Views 

2. Extending the Visualizer Views 

Version