[ANNOUNCE] London Javascript Night - May 25th

Dominic Mitchell dom at happygiraffe.net
Thu Apr 27 15:44:18 BST 2006

On Thu, Apr 27, 2006 at 01:37:39PM +0100, Jonathan Peterson wrote:
> > > [0] <http://prototype.conio.net/>
> You know, if I'd written an entire library without any single solitary 
> comment anywhere in the code*, I probably wouldn't open up my SVN instance 
> to prove the fact. But then I'm not version 2.0 of me, so what do I know.

  % grep // /usr/local/lib/ruby/gems/1.8/gems/rails-1.1.2/html/javascripts/prototype.js
   *  For details, see the Prototype web site: http://prototype.conio.net/
    // removes whitespace-only text node children
      // All *Width and *Height properties give 0 on elements with display none,
      // so enable the element temporarily
        // Opera returns the offset relative to the positioning context, when an
        // element is position relative but top and left have not been defined
    // find the first node with the given tagName, starting from the
    // node the event was triggered on; traverses the DOM upwards
    // set to true if needed, warning: firefox performance problems
    // NOT neeeded for page scrolling, only if draggable contained in
    // scrollable elements
    // must be called before calling withinIncludingScrolloffset, every time the
    // page is scrolled
    // caches x/y coordinate pair to use with overlap
    // within must be called directly before
        // Safari fix
      // find page position of source
      // find coordinate system to use
      // delta [0,0] will do fine with position: fixed elements,
      // position:absolute needs offsetParent deltas
      // correct by body offsets (fixes Safari)
      // set position
  // Safari returns margins on body which is incorrect if the child is absolutely
  // positioned.  For performance reasons, redefine Position.cumulativeOffset for
  // KHTML/WebKit only.

There you go, it has *some* comments.  Not necessarily /useful/, but
there are some.

> Actually there is a file called HEADER that _only_ contains comments, and 
> no code at all. Not sure if that counts. One of the comments in this file 
> isn't "This library is full of hacks to make Javascript more like Ruby, 
> basically", which is a shame, because that would have been helpful.
> Hey ho. 

On a slightly more serious note, if you do want documentation, there is
a good page which covers most of Prototype:


FWIW, I've been doing a reasonable amount of work with Prototype in the
last couple of weeks and I haven't found it at all hard.  Including
delving into the source where necessary.

> [Goes off to drink more coffee and become grumpier]
> J
> * By 'code' I mean stuff like:
> inspect: function() { 
>         return "'" + this.replace(/\\/g, '\\\\').replace(/'/g, '\\\'') + 
> "'"; 
> }

Wow.  Looks like Perl.  I thought he was aiming for Ruby.  :-)

> Lesser mortals might have explained WTF is going on there. Perhaps a 
> useful comment like:
> // Escaping is so badly handled by this raft of technologies that I
> // have to write garbage like this to make stuff work


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