Painfully Obvious → JavaScript

Jan21

Thomas and Amy apparently don’t have enough awesome stuff going on yet, so they’ve decided to release a book on JavaScript performance. Thomas tells me his findings have some implications for how we package Prototype & script.aculo.us.

Jan11

How to write a robust isArray. Faced with a long-standing problem, Juriy finds the solution by reading the spec. Let this be a lesson to all of us.

Jan8

Git has a redesigned homepage that boasts about the major open-source projects that use the up-and-coming DVCS. Prototype is one of them. Thanks, Scott!

Jan5

1

Code: Disabling text selection

Inspired by Thomas’s classic and event delegation.

/**
 *  Element.enableTextSelection(element, isEnabled)
 *  
 *  Enables or disables text selection within the given element.
 *  - element (Element): The element within which a dragging motion
 *    _should_ or _should not_ behave like text selection.
 *  - isEnabled (boolean): Whether to enable or disable text selection.
**/
(function() {
  var IGNORED_ELEMENTS = [];
  function _textSelectionHandler(event) {
    var element = Event.element(event);
    if (!element) return;
    for (var i = 0, node; node = IGNORED_ELEMENTS[i]; i++) {
      if (element === node || element.descendantOf(node)) {
        Event.stop(event);
        break;
      }
    }
  }
  
  if (document.attachEvent)
    document.onselectstart = _textSelectionHandler.bindAsEventListener(window);    
  else
    document.observe('mousedown', _textSelectionHandler);
    

  Element.addMethods({
    enableTextSelection: function(element, isEnabled) {
      if (isEnabled) {
        IGNORED_ELEMENTS = IGNORED_ELEMENTS.without(element);
      } else {
        if (!IGNORED_ELEMENTS.include(element))
          IGNORED_ELEMENTS.push(element);
      }
    }
  });
})();

Dec10

1

This image “evolution” simulator would be a good benchmark for the up-and-coming JavaScript engines… but, sadly, Google Chrome doesn’t yet support Canvas#getImageData. Anyway, both Firefox 3.1b2 and the latest WebKit nightly do very well.

Nov16

2

PDoc: inline documentation for Prototype

As 2008 turns into 2009, it’s past time to dust off some dormant projects in the Prototype realm. I’ve been playing around with PDoc for the first time since April in an effort to get it ready for the next major Prototype release.
Wait — have I not talked about PDoc yet? How is that possible?
OK, here’s what you …

Nov9

No Labs Love for Google Apps. This domain’s e-mail account is hosted by Google Apps — and I use Mail.app to read my e-mail — so the fact that GApps seems to be branched off from all the cool Gmail features is an annoyance for me, too. Good to hear that someone’s trying to fix it.

Nov4

Auto-format Tweets

Used on my “About” page.

(function() {  
  var USERNAMES = /@([A-Za-z0-9_]*)\b/;
  var URLS      = /https?:\/\/([-\w\.]+)+(:\d+)?(\/([\w\/_\.]*(\?\S+)?)?)?/;
  
  function getInnerText(element) {
    element = $(element);
    return element.innerText && !window.opera ? element.innerText :
     element.innerHTML.stripScripts().unescapeHTML().replace(/[\n\r\s]+/g, ' ');
  }
  
  function linkifyTweet(li) {
    var html = li.innerHTML, text = getInnerText(li);

    text.scan(URLS, function(match) {
      html = html.sub(match[0], '<a href="#{0}">#{0}');
    });    
    html = html.gsub(USERNAMES, '<a href="http://twitter.com/#{1}/">#{0}');
    li.update(html);
  }
  
  function init() {
    $('twitter').select('li > span.tweet').each(linkifyTweet);
  }  

  document.observe('dom:loaded', init);  
})();

Oct5

Animating the YouTube Arrow

Whenever I drift into one of my twice-weekly YouTube stream-of-consciousness video-watching binges, I let myself be bothered by a small, inconsequential nitpick.

…

Painfully Obvious

Category: JavaScript