Rendering CSS in a Go Web Application

Question

I wrote a very basic web application, following this tutorial. I want to add css rules in an external stylesheet, but it's not working - when the HTML templates are rendered, something goes wrong and the CSS is completely ignored. If I put the rules in tags, it works, but I don't want to have to deal with that.

In a Go web application, how do I render an external CSS stylesheet?

Solution

Add a handler to handle serving static files from a specified directory.

eg. create {server.go directory}/resources/ and use

http.Handle("/resources/", http.StripPrefix("/resources/", http.FileServer(http.Dir("resources")))) 

along with /resources/somethingsomething.css

The reason for using StripPrefix is that you can change the served directory as you please, but keep the reference in HTML the same.

eg. to serve from /home/www/

http.Handle("/resources/", http.StripPrefix("/resources/", http.FileServer(http.Dir("/home/www/"))))

Note that this will leave the resources directory listing open. If you want to prevent that, there is a good snippet on the go snippet blog:

http://gosnip.posterous.com/disable-directory-listing-with-httpfileserver

Edit: Posterous is now gone, so I just pulled the code off of the golang mailing list and will post it here.

type justFilesFilesystem struct {
    fs http.FileSystem
}

func (fs justFilesFilesystem) Open(name string) (http.File, error) {
    f, err := fs.fs.Open(name)
    if err != nil {
        return nil, err
    }
    return neuteredReaddirFile{f}, nil
}

type neuteredReaddirFile struct {
    http.File
}

func (f neuteredReaddirFile) Readdir(count int) ([]os.FileInfo, error) {
    return nil, nil
}

Original post discussing it: https://groups.google.com/forum/#!topic/golang-nuts/bStLPdIVM6w

And use it like this in place of the line above:

 fs := justFilesFilesystem{http.Dir("resources/")}
 http.Handle("/resources/", http.StripPrefix("/resources/", http.FileServer(fs)))

Comments

[mcriecken]

Are you sure the path to your CSS file that you are linking is correct? Can you comment the <link> tag you are using to link to your stylesheet?

[Lincoln Bergeson]

The rest of my code looks exactly like this: golang.org/doc/articles/wiki/final.go plus two html files that are the templates (edit.html and view.html). Everything's in the same folder. This is my <link> tag: <link rel = "stylesheet" style = "text/css" href = "css_1.css">

[mcriecken]

Can you update the question with your CSS? If you have any syntax errors (i.e., missing colons) in the CSS it can cause the whole thing not to render properly.

[Lincoln Bergeson]

Well, I'm not on that machine right now but maybe I will I am. Thibg is, I copied the CSS directly into style tags and it worked fine, but as soon as I put it in link tags and an external stylesheet it stopped working.

[rofrol]

Works. I had to refresh with ctrl+shift+r in Firefox

[sargas]

@rofrol Gotta not load from cache ;)