battleofthebits.org firki_preview.js improved

$(document).ready(function() {
    // cancel will either:
    // 1. do nothing (was idle)
    // 2. clear debounce timer (waiting for user to stop typing)
    // 3. cancel POST to interpret (debounce timer triggered, i.e. kicked off POST after user stopped typing but user started typing again)
    var cancel = function() {};
    $(document).on('change keyup paste', 'textarea', function() {
        // cancel whatever's going on whenever user does something
        cancel();
        var string = $(this).val();
        var $this = $(this);
        var firki_preview;
        if (string.indexOf("'[") >= 0) {
            // start debounce timer to wait for user to stop typing
            var timeoutId = setTimeout(function() {
                var post = $.post('/api/v1/firki/interpret',
                    { firki_string: string },
                    function(data) {
                        // interpret finished uninterrupted, put cancel back to do nothing (idle)
                        cancel = function() {};
                        var preview_box = $('div.firki_preview');
                        // special case for multiple posts edit
                        if (preview_box.length > 1) {
                            preview_box = $('div.firki_preview', $this.parents('.post'));
                        }
                        if (preview_box.length) {
                            preview_box.html(data[0]);
                        }
                        else {
                            var preview_box = $('<div class="firki_preview inner">' + data + '</div><div class="hMiniSeperator"></div>');
                            $this.after(preview_box);
                        }
                    }
                );
                // POST kicked off, make cancel abort the POST if user starts typing again before POST is finished
                cancel = function() {
                    post.abort();
                };
            }, 150); // <<< CHANGE 150 HERE TO YOUR LIKING
            // make cancel abort the debounce timer if user is still typing before timer fires
            cancel = function() {
                clearTimeout(timeoutId);
            };
        }
    });
});