import json
from django.utils.html import format_html
from ..utils import AttributeDict
from .base import library
from .linkcolumn import BaseLinkColumn
try:
try:
from django.contrib.postgres.fields import HStoreField
from django.db.models import JSONField # django==3.1 moved JSONField
except ImportError:
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().__init__(**kwargs)
[docs] def render(self, record, value):
return format_html(
"<pre {}>{}</pre>",
AttributeDict(self.attrs.get("pre", {})).as_html(),
json.dumps(value, **self.json_dumps_kwargs),
)
[docs] @classmethod
def from_field(cls, field, **kwargs):
if POSTGRES_AVAILABLE:
if isinstance(field, (JSONField, HStoreField)):
return cls(**kwargs)