django-metadata 0.1.0

Compatibility

This library is compatible with:

• python2.6, django1.5

• python2.6, django1.6

• python2.7, django1.5

• python2.7, django1.6

• python2.7, django1.7

• python3.3, django1.5

• python3.3, django1.6

• python3.3, django1.7

• python3.4, django1.5

• python3.4, django1.6

• python3.4, django1.7

Installation

1. Either check out the package from GitHub or it pull from a release via PyPI

   pip install django-metadata

Usage

With django-metadata you can attach metadata to any Django models, you will be able to link keys and theirs values to any instances.

Currently only Redis is supported with only redis-py as backend.

Let’s say you have this model:

# models.py

from django.db import models

class User(models.Model):
    username = models.Charfield(max_length=150)

Now you have to attach the MetadataMixin to your model

# models.py

from django.db import models

from metadata.mixins import MetadataMixin

class User(MetadataMixin, models.Model):
    username = models.Charfield(max_length=150)

You can customize the way django-metadata is storing your values by providing a metadata_key property to your model

# models.py

from django.db import models

from metadata.mixins import MetadataMixin

class User(MetadataMixin, models.Model):
    username = models.Charfield(max_length=150)

    def metadata_key(self):
        return 'metadata:utilisateur:%d' % self.pk

By default, the schema will be metadata:%(lowerclassname)s:%(primary_key)s.

Now we have connected our model to the mixin we can play with the API.

The API of MetadataContainer follows the same principes as dict.

In [1]: from myapp.models import User

In [2]: user = User.objects.create(username='thoas')

In [3]: user.metadata['mail_signup_sent'] = 1

In [4]: user = User.objects.get(username='thoas')

In [5]: user.metadata['mail_signup_sent']
1

In [6]: user.metadata = {'mail_signup_sent': 0}

In [7]: user.metadata['mail_signup_sent']
0

In [8]: del user.metadata['key']

In [9]: user.metadata['key'] # will raises a KeyError

In [10]: user.metadata.get('key', None)
None

In [11]: user.metadata['foo'] = 'bar'

In [12]: user.metadata['foo'] = None

In [13]: user.metadata['foo'] # will raises a KeyError

In [14]: user.metadata.get('foo', None)
None

In [15]: user.metadata['key'] = 'value'

In [16]: user.metadata['foo'] = 'bar'

In [17]: user.metadata = {'foo': None}

In [18]: user.metadata['foo'] # will raises a KeyError

In [19]: user.metadata['key']
value

In [20]: 'value' in user.metadata
True

In [21]: user.metadata.values()
['key']

In [22]: user.metadata.keys()
['value']

In [23]: user.metadata.items()
[('value', 'key')]

In [24]: user.metadata.incr('counter')

In [25]: user.metadata['counter']
1

In [26]: user.metadata.incr('counter', 2)

In [27]: user.metadata['counter']
3

Inspiration

django-metadata comes from an original idea of twidi.