# Synopsis
This module is an add-on for Django REST Framework, based on Django LDP add-on. It serves django models for a notifications component, respecting the Linked Data Platform convention.
It aims at enabling people with little development skills to serve their own data, to be used with a LDP application.



# Models

## Notification
An object representing a notification. A notification has the following fields:

| Field     | Type                   | Default | Description                                               |
| --------- | ---------------------- | ------- | --------------------------------------------------------- |
| `user`    | `ForeignKey` to `User` |         | User targeted by the notification.                        |
| `author`  | `LDPUrlField`          |         | ID of the user at the origin of the notification          |
| `object`  | `LDPUrlField`          |         | ID of the object which is the subject of the notification |
| `type`    | `CharField`            |         | Short description of the notification                     |
| `summary` | `TextField`            |         | Longer description of the notification                    |
| `date`    | `DateTimeField`        | `now`   | Date of the notification                                  |
| `unread`  | `BooleanField`         | `True`  | Indicates that the notification has not been read yet.    |

NB: You can access to all the notifications of a User at `[host]/users/[id]/inbox`



## Subscription

An object allowing a User to be notified of any change on a resource or a container. A subscription has the following fields:

| Field    | Type       | Default | Description                                                  |
| -------- | ---------- | ------- | ------------------------------------------------------------ |
| `object` | `URLField` |         | ID of the resource or the container to watch                 |
| `inbox`  | `URLField` |         | ID of the inbox to notify when the resource or the container change |



# Signals

## Create notification on subscribed objects

When an object is saved, a notification is created for all the subscriptions related to this object.



## Send email when new notification

When a notification is created, an email is sent to the user.

# Django commands

This package also bring a few Django managment command. You can use them 
at the root of your SIB project.

## `mock_notification`

This lets you create mocked notifications. Useful for develpment.  

Usage:

```
python3 manage.py mock_notification [--size <number_of_notifications>]
```

Will create the number of dummy notifications specified by `--size`. 
By default, 0.

## `suppress_old_notifications`

Will suppress old notification. This is a maintenance command to prevent 
the server to blow under the weight of your notifications.

Usage:

```
python3 manage.py suppress_old_notifications [--older <time_period>]
```

This will erase notification older than the time period specified by 
`--older`. By default, 72h ago. `time_period` is expressed in minutes. 
`d`, `h` and `m` suffix are also valid to express periods in days, 
hours and minutes.

Examples:

```shell
# Default. Will delete notifications older than 72h
python3 manage.py mock_notification
# Default. Will delete notifications older than 10 minutes ago
python3 manage.py mock_notification --older 10
# Default. Will delete notifications older than 10 days ago
python3 manage.py mock_notification --older 10d
# Default. Will delete notifications older than 10 hours ago
python3 manage.py mock_notification --older 10h
```