django-chamber

This library contains useful functions and classes mainly for a web development with Django (form and model fields, shortcuts, advanced datastructure, decoraters etc.). For more details see examples below.

Reference

Forms

`chamber.forms.fields.DecimalField`

django.forms.DecimalField with step parameter and validated min and max parameters.

`chamber.forms.widgets.ReadonlyWidget`

Widget for safe rendering of readonly form values.

Models

`chamber.models.fields.SouthMixin`

Mixin for automatic South migration of custom model fields.

`chamber.models.fields.DecimalField`

django.db.models.DecimalField with step, min and max parameters. Uses chamber.forms.fields.DecimalField as default form field.

`chamber.models.fields.RestrictedFileFieldMixin`

Same as FileField, but you can specify:

content_types - list containing allowed content_types. Example: ['application/pdf', 'image/jpeg']
max_upload_size - a number indicating the maximum file size allowed for upload in MB. Maximum upload size can be specified in project settings under MAX_FILE_UPLOAD_SIZE constant

`chamber.models.fields.FileField`

django.db.models.FileField with RestrictedFileFieldMixin options.

`chamber.models.fields.ImageField`

sorl.thumbnail.ImageField (fallback to django.db.models.ImageField) with RestrictedFileFieldMixin options.

`chamber.models.fields.CharNullField`

django.db.models.CharField that stores NULL but returns ''.

Utils

`chamber.utils.remove_accent`

remove_accent('ěščřžýáíé') # 'escrzyaie'

`chamber.utils.get_class_method`

It returns a method of a given class or instance.

`chamber.utils.datastructures.AbstractEnum`

Base enumeration class with controlled __getattr__.

`chamber.utils.datastructures.Enum`

Python's set with AbstractEnum behaviour.

`chamber.utils.datastructures.NumEnum`

Python's dict with AbstractEnum behaviour.

>>> NumEnum('a', 'b')
{'a': 1, 'b': 2}

`chamber.utils.datastructures.AbstractChoicesEnum`

Base choices class (as used in Model field's choices argument).

`chamber.utils.datastructures.ChoicesEnum`

django.utils.datastructures.SortedDict with AbstractEnum and AbstractChoicesEnum behaviour. Useful for string based choices.

>>> enum = ChoicesEnum(('OK', 'ok'), ('KO', 'ko'))
>>> enum
{'OK': 'ok', 'KO': 'ko'}
>>> enum.OK
'ok'
>>> enum.choices
[('OK', 'ok'), ('KO', 'ko')]

`chamber.utils.datastructures.ChoicesNumEnum`

django.utils.datastructures.SortedDict with AbstractEnum and AbstractChoicesEnum behaviour. Useful for integer based choices.

>>> enum = ChoicesNumEnum(('OK', 'ok', 1), ('KO', 'ko', 2))
>>> enum.KO
2
>>> enum.choices
[(1, 'ok'), (2, 'ko')]
>>> enum.get_label(2)
'ko'

`chamber.utils.decorators.classproperty`

Ties property to class, usefull for usage in class methods.

class RestResource(BaseResource):
    @classproperty
    def csrf_exempt(cls):
        return not cls.login_required

    @classmethod
    def as_view(cls, allowed_methods=None, **initkwargs):
        view.csrf_exempt = cls.csrf_exempt

`chamber.utils.decorators.singleton`

Class decorator, which allows for only one instance of class to exist.

`chamber.utils.decorators.short_description`

Sets short_description attribute (this attribute is used by list_display and formulars).

@short_description('amount')
def absolute_amount(self):
    return abs(self.amount)

is equivalent of

def absolute_amount(self):
    return abs(self.amount)
absolute_amount.short_description = 'amount'

`chamber.utils.forms.formset_has_file_field`

Returns True if passed formset contains FileField (or ImageField).

`chamber.utils.http.query_string_from_dict`

Assemble query string from dict of parameters.

>>> query_string_from_dict({'q': 'query1', 'user': 'test'})
u'q=query1&user=test'

Shortcuts

`chamber.shortcuts.get_object_or_none`

Takes Model or QuerySet and arguments and returns instance of Model if exists, None otherwise.

>>> get_object_or_none(User, pk=1)
<User: Gaul Asterix>
>>> get_object_or_none(User.objects.exclude(pk=1), pk=1) or ''
''

`chamber.shortcuts.get_object_or_404`

Takes Model or QuerySet and arguments and returns instance of Model if exists, raises django.http.response.Http404 otherwise.

>>> get_object_or_404(User, pk=1)
<User: Gaul Asterix>
>>> get_object_or_404(User.objects.exclude(pk=1), pk=1)
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/var/ve/lib/python2.7/site-packages/chamber/shortcuts.py", line 21, in get_object_or_404
    raise Http404
Http404

`chamber.shortcuts.distinct_field`

Takes Model or QuerySet and distinction parameters and returns list of unique values.

>>> User.objects.filter(last_name='Gaul')
[<User: Gaul Obelix>, <User: Gaul Asterix>]
>>> distinct_field(User.objects.filter(last_name='Gaul'), 'last_name')
[(u'Gaul',)]

`chamber.shortcuts.filter_or_exclude_by_date`

Takes negate bool (True for exclude, False for filter), Model or QuerySet and date parameters and return queryset filtered or excluded by date parameters.

>>> Order.objects.values_list('created_at', flat=True)
[datetime.datetime(2014, 4, 6, 15, 56, 16, 727000, tzinfo=<UTC>),
 datetime.datetime(2014, 2, 6, 15, 56, 16, 727000, tzinfo=<UTC>),
 datetime.datetime(2014, 1, 11, 23, 15, 43, 727000, tzinfo=<UTC>)]
>>> filter_or_exclude_by_date(False, Order, created_at=date(2014, 2, 6))
[<Order: MI-1234567>]
>>> filter_or_exclude_by_date(False, Order, created_at=date(2014, 2, 6))[0].created_at
datetime.datetime(2014, 2, 6, 15, 56, 16, 727000, tzinfo=<UTC>)

`chamber.shortcuts.filter_by_date`

Shortcut for chamber.shortcuts.filter_or_exclude_by_date with first parameter False.

`chamber.shortcuts.exclude_by_date`

Shortcut for chamber.shortcuts.filter_or_exclude_by_date with first parameter True.

Development

For contribution go to example directory and call make install to install an example project.

Testing

To run tests go to example directory and call make test.

License

See LICENSE file.

fazpu / django-chamber