You should define and standard-footer as separate functions for two reasons. First, during development you can redefine those functions and see the effect immediately without having to recompile functions that use the :mp3-browser-page macro. Second, it turns out that one of the pages you’ll write later won’t be defined with :mp3-browser-page but will still need the standard header and footers. They look like this:

    1. (defparameter *r* 25)
    3. (defun standard-header ()
    4.   (html
    5.    ((:p :class "toolbar")
    6.     "[" (:a :href (link "/browse" :what "genre") "All genres") "] "
    7.     "[" (:a :href (link "/browse" :what "genre" :random *r*) "Random genres") "] "
    8.     "[" (:a :href (link "/browse" :what "artist" :random *r*) "Random artists") "] "
    9.     "[" (:a :href (link "/browse" :what "album") "All albums") "] "
    11.     "[" (:a :href (link "/browse" :what "song" :random *r*) "Random songs") "] "
    12.     "[" (:a :href (link "/playlist") "Playlist") "] "
    13.     "[" (:a :href (link "/all-playlists") "All playlists") "]")))
    15.   (html (:hr) ((:p :class "footer") "MP3 Browser v" *major-version* "." *minor-version*)))

    A couple of smaller HTML macros and helper functions automate other common patterns. The :table-row HTML macro makes it easier to generate the HTML for a single row of a table. It uses a feature of FOO that I’ll discuss in Chapter 31, an &attributes parameter, which causes uses of the macro to be parsed just like normal s-expression HTML forms, with any attributes gathered into a list that will be bound to the &attributes parameter. It looks like this:

    1. (:a :href "browse?what=artist&genre=Rhythm+%26+Blues" "Artists")

    you can write the following:

    It looks like this:

    2.   (html 
    3.     (:attribute
    4.      (:format "~a~@[?~{~(~a~)=~a~^&~}~]" target (mapcar #'urlencode attributes)))))

    Finally, you need the CSS style sheet mp3-browser.css used by :mp3-browser-page. Since there’s nothing dynamic about it, it’s probably easiest to just publish a static file with publish-file.

    1. (publish-file :path "/mp3-browser.css"  :file filename :content-type "text/css")

    A sample style sheet is included with the source code for this chapter on the book’s Web site. You’ll define a function, at the end of this chapter, that starts the MP3 browser application. It’ll take care of, among other things, publishing this file.