Javascript delaying

In need of executing Javascript after the page has loaded, or something else has been initialized I came up with a simple but useful tiny "Delayer":

/**
 * @param handler a callback accepting Delayer.dispatch as argument
 */
function Delayer(handler) {
    var self = this;

    this.dispatch = function() {
        for (var i = 0; i < self.length; ++i) {
            console.log("running delayed init "+i+": "+self[i]);
            self[i]();
        }
    };

    if (typeof handler == "function" || handler instanceof Function) {
        handler(this.dispatch);
    }
}

Delayer.prototype = Array.prototype;

It can be initialized the following way:

/* e.g. with jQuery */
window.delayedInits = new Delayer($(document).ready);
/* e.g. with Facebook */
window.fbDelayedInits = new Delayer(function(dp){window.fbAsyncInit = dp;});

Then you push your work the usual way:

delayedInits.push(function() {alert("Hello, delayed!");});

WebSockets Handshake non HTTP conforming?

Update:

Just found a revelatory discussion. The summary of Bjoern Hoehrmann is especially interesting with regards to that topic.

---

While skimming through the new HTML5 WebSocket draft, I noticed the following exemplar HTTP message demonstrating the client message of a WebSocket handshake:

        GET /demo HTTP/1.1
        Host: example.com
        Connection: Upgrade
        Sec-WebSocket-Key2: 12998 5 Y3 1  .P00
        Sec-WebSocket-Protocol: sample
        Upgrade: WebSocket
        Sec-WebSocket-Key1: 4 @1  46546xW%0l 1 5
        Origin: http://example.com

        ^n:ds[4U

To me this looks non conforming to the HTTP spec due to the lack of an indicator that the request contains a message body.

Quoting the 4th paragraph of section 4.3 of RFC2616:

The presence of a message-body in a request is signaled by the inclusion of a Content-Length or Transfer-Encoding header field in the request's message-headers. A message-body MUST NOT be included in a request if the specification of the request method (section 5.1.1) does not allow sending an entity-body in requests. A server SHOULD read and forward a message-body on any request; if the request method does not include defined semantics for an entity-body, then the message-body SHOULD be ignored when handling the request.

Huh?

Two pitfalls in one afternoon

This is not my day.

<quote url="http://dev.mysql.com/doc/refman/5.0/en/fulltext-search.html">
words that are present in more than 50% of the rows are considered common and do not match
</quote>

RTFM! ;)

Apache MultiViews are evil

Suppose you've got a similar setup to:

RewriteEngine On
RewriteBase /

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule .* - [QSA,L]

RewriteRule ^network/?(w+)?$ network.php?path=$1

Apache will expand e.g. "network/foo/bar" to "network.php/foo/bar" which won't be expanded to "network.php?f=" because it --of course-- exists (RewriteCond -f).

Evil! :)

Apache2 mod_domaintree version 1.3

I just released mod_domaintree-1.3 on freshmeat.

It'll take some time to appear, though.

The code has been cleaned up a lot and a host name to directory cache (per server/process) has been added.

Enable the cache by setting DomainTreeCache to a reasonable high number, like the amount of different domains being hosted.

Drop me a mail if you like it! ;)

Update: overflow:auto in Mozilla

If you want the page to scroll when the scrolling-enabled DIV has nothing to scroll you'll have to wrap the contents of the scrollMe function into the following if statement:

function scrollMe(event)
{
    if (event.currentTarget.scrollHeight >
        event.currentTarget.offsetHeight) {
        // ...
    }
}

Have fun!

Scrollable overflow:auto Elements in Mozilla

Doing some extensive Javascript work lately, I managed to make HTML elements styled with //overflow:auto// scrollable in Mozilla.

Just place this snippet at the bottom of your page with DIV elements that have scroll as classname:

<script type="text/javascript"> <!--
  // enable scrolling for overflow:auto elements in Mozilla
  function scrollMe(event)
  {
    var st = event.currentTarget.scrollTop;
    st += (event.detail * 12);
    event.currentTarget.scrollTop = st < 0 ? 0 : st;
    event.preventDefault();
  }
  if (document.body.addEventListener) {
    var divs = document.getElementsByTagName('DIV');
    for (var d in divs) {
      if (divs[d].className && divs[d].className == 'scroll') {
        try {
          divs[d].addEventListener(
               'DOMMouseScroll', scrollMe, false);
        } catch (ex) {}
      }
    }
  }
  // -->
</script>

I already posted a feature request to embed something similar in pearweb.