Using Conkeror for Web Development

Script Injection

You can load any toolkit you want into a page by adding a <script> tag to the I.buffer.document object.

JQuery

For example, you can load JQuery from Google Ajaxlibs without prior planning:

function install_jquery(d) {
    var script_el = d.createElementNS(XHTML_NS, "script");
    script_el.setAttribute("language", "javascript");
    script_el.setAttribute("type", "text/javascript");
    script_el.setAttribute("src", "http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js");
    d.body.appendChild(script_el);
}

function jquery_this_doc(d, js_code) {
    install_jquery(d);
    var script_el = d.createElementNS(XHTML_NS, "script");
    script_el.textContent = js_code;
    d.body.appendChild(script_el);
}

interactive("jquery-here",
            "load jquery.js into this page, then your command",
            function(I) {
                jquery_this_doc(I.buffer.document, (yield I.minibuffer.read($prompt = "jq: ", $history = "jquery-here")));
                // Providing a $history is what allows editing/replay of earlier commands
            });

To use this,

  M-x jquery-here
  jq: $("h1").css("backgroundColor", "blue");

should turn all of the H1 headings blue. The convenient bit is that you can re-run the command and edit it in place, just like any other minibuffer-prompt, letting you experiment with selectors "live"; just reload the page to undo everything and start again.