get_static_url in static templatetags

[ohardy]

Hello,

When using the settings STATICFILES_STORAGE, it's the storage that should return the url.

For example, a tag of this type works very well:

@register.simple_tag()
def get_static_url(filepath):
    if storage.exists(filepath):
        return storage.url(filepath)
    return None

and so STATIC_URL is not required anymore

[ohardy]

Forget that before:

from django import template
from django.core.files.storage import get_storage_class

register = template.Library()

storage = get_storage_class(settings.STATICFILES_STORAGE)()

[Jannis Leidel]

I'm not sure how that would be an improvement to the get_static_prefix template tag, to be honest. Would you mind to elaborate?

​http://docs.djangoproject.com/en/dev/ref/contrib/staticfiles/#the-get-static-prefix-templatetag

[ohardy]

Several differences:

• STATIC_URL is not required since the storage is constructing the URL
• If a storage wants to build a URL encoded, for example, it is impossible to build this URL with STATIC_URL.
• STATIC_URL been given duplicate such that for S3 storage as we already set the URL when you declare storage.

All these remarks also apply to MEDIA_URL

[Jannis Leidel]

Having given this a bit more thought, I'm convinced this is a useful. There are a few edge cases though:

1. The docs need to carefully explain how the storage influences the result of this template tag, e.g. signed URLs, increased latency with remote storage backends etc. It's usually also a pretty advanced topic, so we need to make sure this won't confuse beginners.

2. FileFields and ImageFields can be passed different storage backends, which is why the template tag doesn't completely apply to MEDIA_URL. It should probably check whether it's passed a file instance or a string, e.g.

@register.simple_tag()
def get_media_url(file_or_path):
    if isinstance(file_or_path, UploadedFile):
        return file_or_path.url
    return storage.url(file_or_path)

[Jannis Leidel]

initial patch

[Jannis Leidel]

The attached patch implements this idea solely for staticfiles since I don't believe it's really needed for MEDIA_URL (and the file storage backends) -- the filefields are capable of returning the url themeselves.

[Jannis Leidel]

Adds working hashed file storage backend

[Jannis Leidel]

Adds working hashed file storage backend

[Jannis Leidel]

Sorry for the double upload, I just updated the patch to be against the latest trunk.

[Jannis Leidel]

Latest state of the Github repo at ​https://github.com/jezdez/django/compare/feature/staticfiles-templatetag

[Jannis Leidel]

In [16594]:

Fixed #15252 -- Added static template tag and CachedStaticFilesStorage to staticfiles contrib app.

Many thanks to Florian Apolloner and Jacob Kaplan-Moss for reviewing and eagle eyeing.