orf / django-choice-object

A choice object for Django

Django choice object

I am a choice object for Django. I make using choices in forms and models easier.

Deprecated: This is not needed since Django 3.0 which includes enumeration types which work similarly.

Install

pip install django-choice-object

Usage

Choice classes inherit from Choice. Each attribute can have one or two values, the first being the value to be stored in the database and the second optional one being the display text. If no display text is given then it is created from the attribute name.

Example

from django_choice_object import Choice
from django.db import models
    
class SomeChoice(Choice):
    FIRST_CHOICE = 1
    SECOND_CHOICE = 2
    THIRD_CHOICE = 3
    LAST_CHOICE = 4, "I am the display text"
    
class SomeModel(models.Model):
    some_field = models.IntegerField(choices=SomeChoice)
    
>>> list(SomeChoice)
[(1, 'First Choice'), (2, 'Second Choice'), (3, 'Third Choice'), (4, 'I am the display text')]
>>> SomeModel.objects.filter(some_field=SomeChoice.FIRST_CHOICE).all()
[object list...]
>>> SomeModel.objects.get(id=1).some_field
1
>>> SomeModel().some_field = SomeChoice.LAST_CHOICE

Advanced stuff

Grouping

Grouping choice values is a fairly common need. You can add groups of values to a choice like so:

class ChoiceWitHGroups(Choice):
    FIRST = 1
    SECOND = 2
    THIRD = 3
    FOURTH = 4
    
    START_GROUP = {FIRST, SECOND}
    END_GROUP = {THIRD, FOURTH}

Any value that ends with _GROUP and is a set will be ignored as a choice.

Ordering

Choices can be ordered in three ways. The default is by the value, but this can be configured using the _order_by attribute:

class TestChoiceOrdered(Choice):
    LAST = 1, "zzzzzzzzz"
    FIRST = 2, "aaaaaaaa"
    _order_by = "name"

In the code snippet above the FIRST attribute would appear first as they are sorted by the name rather than the value.

You can also specify a custom sorting key:

class WeirdChoice(Choice):
    LAST = 'last', 'Last', 10
    FIRST = 'first', 'First', 1

    @staticmethod
    def _get_sort_key(value):
        return value[2]

In this case the third item in the tuple would be the item to sort on.

Contributing

• Set up a virtualenv: virtualenv .
• Install the requirements: pip install -r requirements.txt
• Run the tests: nosetests .

django-choice-object's Issues

Improved ordering options

Hi,

I have a use case where I want to explicitly order the options but want to maintain "slugs" for the keys. I can do something horrible where we order by the display names but they're actually objects with __str__ and __cmp__ but that's horrible. It would be awesome to be able to define something like this:

class MyChoices(ChoiceObject):
    _order_key = 2
    APPLES = ('apples', 'Apples', 1)
    BANANAS = ('bananas', 'Bananas', 0)

i.e. if _order_key is set go with that instead of _order_by. Or just being able to set _order_by in this manner instead. We would need to keep the "original" data to sort on as well as the current dict in _data.

I'm happy to provide a PR for this if you think it's a nice idea.

support for Python3

Is django-choice-object works with Python3. As I upgraded my code from Python2 to Python3 and I'm not sure about it.

Is nose necessary?

Is there any reason why we are using nose tests? Running python django_choice_object/tests.py would be just as simple, and seems like it should be possible given the __main__ block at the bottom of the file. You can't run either option at will due to the different python paths/imports. Perhaps actually just having a top level tests.py which runs with unittest and is outside of the shipped package would make most sense.