Link to Flask static files with url_for

Question

How do you use url_for in Flask to reference a file in a folder? For example, I have some static files in the static folder, some of which may be in subfolders such as static/bootstrap.

When I try to serve a file from static/bootstrap, I get an error.

 <link rel=stylesheet type=text/css href="{{ url_for('static/bootstrap', filename='bootstrap.min.css') }}">

I can reference files that aren't in subfolders with this, which works.

 <link rel=stylesheet type=text/css href="{{ url_for('static', filename='bootstrap.min.css') }}">

What is the correct way to reference static files with url_for? How do I use url_for to generate urls to static files at any level?

ghickman · Accepted Answer · 2015-05-22 10:12:10Z

You have by default the static endpoint for static files. Also Flask application has the following arguments:

static_url_path: can be used to specify a different path for the static files on the web. Defaults to the name of the static_folder folder.

static_folder: the folder with static files that should be served at static_url_path. Defaults to the 'static' folder in the root path of the application.

It means that the filename argument will take a relative path to your file in static_folder and convert it to a relative path combined with static_url_default:

url_for('static', filename='path/to/file')

will convert the file path from static_folder/path/to/file to the url path static_url_default/path/to/file.

So if you want to get files from the static/bootstrap folder you use this code:

<link rel="stylesheet" type="text/css" href="{{ url_for('static', filename='bootstrap/bootstrap.min.css') }}">

Which will be converted to (using default settings):

<link rel="stylesheet" type="text/css" href="static/bootstrap/bootstrap.min.css">

Also look at url_for documentation.

davidism · Accepted Answer · 2021-03-29 15:26:05Z

In my case I had special instruction into nginx configuration file:

location ~ \.(js|css|png|jpg|gif|swf|ico|pdf|mov|fla|zip|rar)$ { try_files $uri =404; }

All clients have received '404' because nginx nothing known about Flask.

The primary configuration file is /etc/nginx/nginx.conf on Linux. It may be similar on Windows.

Hard-coding a list of file extensions like that seems like it will create surprises and toil to maintain. Probably better to use something that explicitly mentions the /static/ path prefix and then serves whatever file the user requests from within that static directory. Also ensure you avoid common nginx errors with that setup.

Collectives™ on Stack Overflow

Link to Flask static files with url_for

2 Answers 2

Comments

1 Comment

Hot Network Questions