# coding: utf-8
from __future__ import absolute_import, unicode_literals
import os
from django.db import models
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
[docs]@library.register
class FileColumn(BaseLinkColumn):
'''
Attempts to render `.FieldFile` (or other storage backend `.File`) as a
hyperlink.
When the file is accessible via a URL, the file is rendered as a
hyperlink. The `.basename` is used as the text::
<a href="/media/path/to/receipt.pdf" title="path/to/receipt.pdf">receipt.pdf</a>
When unable to determine the URL, a ``span`` is used instead::
<span title="path/to/receipt.pdf">receipt.pdf</span>
`.Column.attrs` keys ``a`` and ``span`` can be used to add additional attributes.
Arguments:
verify_exists (bool): attempt to determine if the file exists
If *verify_exists*, the HTML class ``exists`` or ``missing`` is
added to the element to indicate the integrity of the storage.
text (str or callable): Either static text, or a callable. If set, this
will be used to render the text inside the link instead of
the file's basename (default)
'''
def __init__(self, verify_exists=True, **kwargs):
self.verify_exists = verify_exists
super(FileColumn, self).__init__(**kwargs)
def text_value(self, record, value):
if self.text is None:
return os.path.basename(value.name)
return super(FileColumn, self).text_value(record, value)
def render(self, record, value):
storage = getattr(value, 'storage', None)
exists = None
url = None
if storage:
# we'll assume value is a `django.db.models.fields.files.FieldFile`
if self.verify_exists:
exists = storage.exists(value.name)
url = storage.url(value.name)
else:
if self.verify_exists and hasattr(value, 'name'):
# ignore negatives, perhaps the file has a name but it doesn't
# represent a local path... better to stay neutral than give a
# false negative.
exists = os.path.exists(value.name) or exists
tag = 'a' if url else 'span'
attrs = AttributeDict(self.attrs.get(tag, {}))
attrs['title'] = value.name
classes = [c for c in attrs.get('class', '').split(' ') if c]
if exists is not None:
classes.append('exists' if exists else 'missing')
attrs['class'] = ' '.join(classes)
if url:
return self.render_link(url, record=record, value=value, attrs=attrs)
else:
return format_html(
'<span {attrs}>{text}</span>',
attrs=attrs.as_html(),
text=self.text_value(record, value)
)
@classmethod
def from_field(cls, field):
if isinstance(field, models.FileField):
return cls(verbose_name=title(field.verbose_name))