[FIXED] Pretty print django.db.models.JSONField in Django admin?

Issue

Django >= 3.1 supports a new JSONField model field. I am using one like this:

from django.db import models

class Example(models.Model):
    foobar = models.JSONField()

I've also included this model in Django's admin section. However, the field is just a simple textarea with the JSON included, not pretty printed.

How can I make sure the JSON displayed in Django's admin section is pretty printed, with indentation, like this:

{
  "example": {
     "a": 1,
     "b": 2
  }
}

Solution

I was looking for the same thing and found this post, where they use the pygments module: https://daniel.feldroy.com/posts/pretty-formatting-json-django-admin

import json
from django.contrib import admin
from pygments import highlight
from pygments.lexers import JsonLexer
from pygments.formatters import HtmlFormatter
from django.utils.safestring import mark_safe

class YourModelAdmin(admin.ModelAdmin):

    def pretty_json(self, instance):
        """Function to display pretty version of our data"""

        # Convert the data to sorted, indented JSON
        response = json.dumps(instance.metadata, sort_keys=True, indent=2) # <-- your field here

        # Truncate the data. Alter as needed
        response = response[:5000]

        # Get the Pygments formatter
        formatter = HtmlFormatter(style='colorful')

        # Highlight the data
        response = highlight(response, JsonLexer(), formatter)

        # Get the stylesheet
        style = "<style>" + formatter.get_style_defs() + "</style><br>"

        # Safe the output
        return mark_safe(style + response)

    pretty_json.short_description = 'Pretty json'

Answered By - Saigesp