Gist Embeds Redux

gist.js

var gistPrefix = 'http://gist.github.com/',

    fileAnchorPrefix = '#file_',
    
    // Cache document.write so that it can be restored once all Gists have been
    // embedded.
    cachedWrite = document.write,

    body = $('body'),

    // Map each p.gist to an object that contains the paragraph to be replaced,
    // the Gist's identifier, and the file name (if specified).
    gists = $('p.gist').map(function(n, p) {
        p = $(p);

        var a = $('a', p),
            href = a.attr('href'),
            parts;

        // Only return the mapping if a valid a exists in the p.
        if (a.length && href.indexOf(gistPrefix) == 0) {
            parts = href.substring(gistPrefix.length).split(fileAnchorPrefix);

            return {
                p: p,
                id: parts[0],
                file: a.data('file')
            };
        }
        else {
            return undefined;
        }
    }).get(),
    
    embedNextGist = function() {
        // If there are no more Gists to embed, restore document.write.
        if (gists.length == 0) {
            document.write = cachedWrite;
        }
        else {
            var gist = gists.shift();

            // The Gist javascript file consists of a call to document.write to
            // write the stylesheet link element and a second call to
            // document.write to write the div containing the marked up Gist.

            // So, override document.write to catch the first call. And inside
            // that override, override document.write again to catch the second
            // call.

            document.write = function(styleLink) {
                // I have a slightly modified version of GitHub's Gist
                // stylesheet already included in my page template, so I ignore
                // stylesheet written here. If you don't want to do that, you
                // could do something here like $('head').append(styleLink);

                document.write = function(gistDiv) {
                    // Replace the original paragraph with the formatted div
                    // written by the Gist javascript file.
                    gist.p.replaceWith(gistDiv);

                    embedNextGist();
                };
            };

            body.append(
                '<scr' + 'ipt src="' + gistPrefix + gist.id + '.js' +
                    (gist.file ? '?file=' + gist.file : '') + '"></scr' + 'ipt>'
            );
        }
    };

// One call to embedNextGist to get the ball rolling.
embedNextGist();

gist.min.js

var e=document.write,f=$("body"),g=$("p.gist").map(function(b,a){var a=$(a),d=$("a",a),c=d.attr("href");if(d.length&&c.indexOf("http://gist.github.com/")==0)return c=c.substring(23).split("#file_"),{a:a,id:c[0],file:d.data("file")}}).get();function h(){if(g.length==0)document.write=e;else{var b=g.shift();document.write=function(){document.write=function(a){b.a.replaceWith(a);h()}};f.append('<scr'+'ipt src="http://gist.github.com/'+b.id+".js"+(b.file?"?file="+b.file:"")+'"><\/scr'+'ipt>')}}h();

usageAfter.html

<p class="gist"><a href="http://gist.github.com/123#file_first_file.js" data-file="firstFile.js">Gist 123: firstFile.js</a></p>

usageBefore.html

<p class="gist"><a href="http://gist.github.com/637764">Gist 637764</a></p>