# coding: utf-8
from __future__ import absolute_import, unicode_literals
import json
from django.utils.html import format_html
from django_tables2.templatetags.django_tables2 import title
from django_tables2.utils import AttributeDict
from .base import library
from .linkcolumn import BaseLinkColumn
try:
from django.contrib.postgres.fields import HStoreField, JSONField
POSTGRES_AVAILABLE = True
except ImportError:
# psycopg2 is not available, cannot import from django.contrib.postgres.
# JSONColumn might still be useful to add manually.
POSTGRES_AVAILABLE = False
[docs]@library.register
class JSONColumn(BaseLinkColumn):
'''
Render the contents of `~django.contrib.postgres.fields.JSONField` or
`~django.contrib.postgres.fields.HStoreField` as an indented string.
.. versionadded :: 1.5.0
.. note::
Automatic rendering of data to this column requires PostgreSQL support
(psycopg2 installed) to import the fields, but this column can also be
used manually without it.
Arguments:
json_dumps_kwargs: kwargs passed to `json.dumps`, defaults to `{'indent': 2}`
attrs (dict): In addition to *attrs* keys supported by `~.Column`, the
following are available:
- *pre* -- ``<pre>`` around the rendered JSON string in ``<td>`` elements.
'''
def __init__(self, json_dumps_kwargs=None, **kwargs):
self.json_dumps_kwargs = json_dumps_kwargs if json_dumps_kwargs is not None else {'indent': 2}
super(JSONColumn, self).__init__(**kwargs)
def render(self, record, value):
return format_html(
'<pre {}>{}</pre>',
AttributeDict(self.attrs.get('pre', {})).as_html(),
json.dumps(value, **self.json_dumps_kwargs)
)
@classmethod
def from_field(cls, field):
if POSTGRES_AVAILABLE:
if isinstance(field, JSONField) or isinstance(field, HStoreField):
return cls(verbose_name=title(field.verbose_name))