django-normalized-filefield 0.1.1

Normalized file filed for Django

File field that behaves as close to other fields as possible.

22. 0.1.1

Whaat?

This!

Screenshots

(animated gif)

Whaaaaat?! I don get it!

Basic idea: I want to handle file inputs no differently from other inputs!

• If a text input can have its value “sent back” when form validation fails, so must the file input!

• Even when a file field is required, user should still be able to clear it (just as they can delete text in a required text field) no matter that the field validation will fail!

File inputs in HTML are a bit different that other inputs (“text”, “checkbox”, etc). Amount of data involved in a typical “file” field is much larger then what is in fields on any other type. It is one thing to send and return (in the case of form validation error) a few characters in a text input, another thing completely to send and return megabytes of data in files - it’s not practical.

On the server side this means that files have to be handled differently as well. Usually they are saved in a temporary place and it is up to the developer to copy them where needed.

Django hides some of this boilerplate away, making working with file fields a bit simpler. But still it is different from other fields. As this package demonstrates, there is no real need for this, as file fields can be made to behave like other fields.

This package normalizes the behaviour of file fields by extending django.forms.fields.FileField and altering its behaviour to be as close to other input types as possible.

It is meant to be a drop-in replacement for django.forms.fields.FileField though some considerations are needed.

Versions

Testes in all combinations of:

Django	Python
1.7.11	2.7.10
1.8.8	3.4.3
1.9.1	3.5.1

Differences from FileField

• TODO expand this section with details

Not much… The “Clear” checkbox is present in some situations where the ClearableFileInput does not render it.

Also, there is a new state for the field. In addition to “empty” and “initial” that traditional ClearableFileInput renders as a single HTML input element or as a double input with the link and label “Currently”, this widget also has a “Selected” state. This is similar to state with the “Currently” link, but it renders just the name of the file without the link. It is used in situations when form validation has failed, but the file field is ok and the file has been saved to temporary storage (cache).

Usage

In Models

A model field is provided to make use with models simpler. The only difference from the normal models.field.FileField is that it specifies a different form field class, namely NormalizedFileField.

from normalized_filefield.model_field import NormalizedFileField

class MyModel(models.Model):
    a_file = NormalizedFileField(upload_to='media/place')
    ...

Note: In keeping with (dubious) tradition of how field classes are named in Django (forms.field.FileField vs models.fields.FileField), this package also names form and model field the same, NormalizedFileField.

In Forms

from normalized_filefield.form_field import NormalizedFileField

class MyModelForm(forms.ModelForm):
    a_file = NormalizedFileField()

Widget normalized_filefield.widget.NormalizedFileInput is only meant to be used together with this form field class.

Changing the markup

The widget markup can be changed. Nothing different here then what regular ClearableFileInput provides. One difference is that template strings are made with the “format” syntax instead of the old “percent” syntax.

See normalized_filefield.widget.VerboseHTMLMixin for a very verbose markup option.

• TODO expand this section

TODO

• [ ] File cache storage seems not to clear automatically,

• [ ] Styleable version, JS

• [ ] Image Field

• [ ] Clean up the widget and form classes (make more mixin-friendly structure)