django-nps 1.1

Django app supporting Net Promoter Score (NPS) surveys.

# Django NPS

Django app supporting Net Promoter Score (NPS) surveys

## Compatibility

This package support Django 3.2+, Python 3.8+.

## Background - Net Promoter Score

The NPS is a measure of customer loyalty that is captured by asking your
customers a singe question:

> How likely is it that you would recommend our
> [company|product|service] to a friend or colleague?"

The answer to this question is a number from 0-10 (inclusive). These scores
are then broken out into three distinct groups: 'detractors' (0-6), 'neutral'
(7-8) and 'promoters' (9-10). The NPS is then the difference between the
number of promoters and detractors (as a percentage of the whole population).

For example, if you ask 100 people, and you get the following results:

```
detractors: 20%
neutrals:   10%
promoters:  70%
```

Then your NPS is 70 - 20 = 50. *(NPS is expressed as a number, not a %)*

NPS was orginally developed at the strategy consultants Bain & Company
by Fred Reichheld in 2003. They retain the registered trademark for NPS,
and you can read all about the history of it on their site "[Net Promoter System](http://netpromotersystem.com/about/index.aspx)".

## Usage

This app is used to store the individual scores, and calculate the NPS
based on these. It does not contain any templates for displaying the
question itself, neither does it put any restriction around how often
you ask the question, or to whom. It is up to the app developer to
determine how this should work - each score is timestamped and linked to
a Django User object, so you can easily work out the time elapsed since
the last time they were asked.

For example, if you want to ensure that you only survey users every X days,
you can add a context property to the template using the `display_to_user`
method:

```python
>>> # only show the survey every 90 days
>>> UserScore.objects.days_since_user_score(request.user) > 90
True
```

If you then show the survey - the output of which is a single value (the
score) together with an optional reason ("what is the main reason for
your score"), is then posted to the ``post_score`` endpoint, which
registers the user score.

The NPS value itself can be calculated on any queryset of ``UserScore``
objects - which allows you to track the score based on any attribute of
the score itself or the underlying user. For instance, if you have
custom user profiles, you may wish to segement your NPS by
characteristics of those profiles.

```python
>>> # December's NPS
>>> UserScore.objects.filter(timestamp__month=12).net_promoter_score()
50
```

The `post_score` endpoint returns a `JsonResponse` which contains a
`'success': True|False` value together with the `UserScore` details:

```python
{
    "success": True,
    "score": {"id": 1, "user": 1, "score": 0, "group": "detractor"}
}
```
If the score was rejected, the errors are returned in place of the score (errors
are a list of lists, as returned from the Django `Form.errors` property):

```python
{
    "success": False,
    "errors": [["score", "Score must be between 0-10"]]
}
```

The app contains a piece of middleware, `NPSMiddleware`, which will add an
attribute to the `HttpRequest` object called `show_nps`. If you add the
middleware to your settings:

```python
# settings.py
MIDDLEWARE_CLASSES = (
    # standard django middleware
    'django.middleware.common.CommonMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    ...
    'net_promoter_score.NPSMiddleware',
)
```

You can then use this value in your templates:

```html
<!-- show_nps template = {{request.show_nps}} -->
{% if request.show_nps %}
    <div>HTML goes here</div>
{% endif %}
```

## Settings

**NPS_DISPLAY_INTERVAL**

The number of days between surveys, integer, defaults to 30. This value is used
by the default `show_nps` function to determine whether someone should be shown
the survey.

**NPS_DISPLAY_FUNCTION**

A function that takes an `HttpRequest` object as its only argument, and which
returns True if you want to show the survey. This function is used by the
`net_promoter_score.show_nps` function. It defaults to return True if the
request user has either never seen the survey, or hasn't seen it for more days
than the `NPS_DISPLAY_INTERVAL`.

This function should be overridden if you want fine-grained control over
the process - it's the main hook into the app.

## Tests

There is a full suite of tests for the app, which are best run through `tox`. If
you wish to run the tests outside of tox, you should install the requirements first:

```
$ pip install -r requirements.txt
$ python manage.py test
```

## License

MIT

## Contributing

Usual rules apply:

1. Fork to your own account
2. Create a branch, fix the issue / add the feature
3. Submit PR

Please take care to follow the coding style - and PEP8.

## Acknowledgements

Credit is due to **epantry** for the [original project](https://github.com/epantry/django-netpromoterscore) from which this was forked.

Thanks also to the kind people at **Eldarion** ([website](http://eldarion.com/))
for releasing the PyPI package name.