dj-jsonfield

Why fork

I need to use django-jsonfield with jsonfield. Unfortunately, both have been using the same package name jsonfield, so I have to maintain a fork.

Difference from upstream

Rename package name from jsonfield to dj_jsonfield.

Introduction

I had a serious need for a JSON field for django. There were a couple out there, but none packaged up nicely on bitbucket/github that were usable with pip install -e.

So I took the code from David Cramer's blog, and packaged it up.

Usage

To use, just install the package, and then use the field:

from django.db import models
import dj_jsonfield

class MyModel(models.Model):
    the_json = dj_jsonfield.JSONField()

You can assign any JSON-encodable object to this field. It will be JSON-encoded before being stored in the database as a text value and it will be turned back into a python list/dict/string upon retrieval from the database.

There is also a TypedJSONField, that allows you to define data types that must be included within each object in the array. More documentation to follow.

Notes

If no default is provided, and null=True is not passed in to the field constructor, then a default of {} will be used.

Supported django versions

All versions of Django from 1.8 onwards are tested, however, if you are using Postgres, I highly recommend that you consider using the django.contrib.postgres module's JSONField instead.

Extras

jsonify templatetag

This allows you to convert a python data structure into JSON within a template:

{% load jsonify %}

<script>
var foo = {{ bar|jsonify|safe }};
</script>

Note that you must only use the "safe" filter when you use the jsonify filter within a <script> tag (which is parsed like a CDATA section).

If you use it in some other places like in an HTML attribute, then you must not use the safe filter so that its output is properly escaped:

<div data-foo="{{ bar|jsonify }}">

The above rules are important to avoid XSS attacks with unsafe strings stored in the converted data structure.

Todo

Allow for passing in a function to use for processing unknown data types.

Convert date/time objects nicely to/from ISO strings (YYYY-mm-dd HH:MM:SS TZNAME). This is actually a bit tricky, as we don't know if we are expecting a date/time object. We may parse objects as we go, but there could be some performance issues with this. I'm tempted to say "only do this on TypedJSONField()"

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