After all the work of WASP and others to promote clean markup, valid pages and graceful degradation via css - it sucks that we're going back to tag soup days by throwing javascript tags into our html.

The better way to do javascript is to do it unobtrusively. PPK and Simon Willison have been recommending this approach for ages. And it's definitely the way to go. The only problem is that it's a bit of a pain in the ass.

That's why I came up with Behaviour - my solution to unobtrusive javascript behaviours.

How does it work?

Behaviour lets you use CSS selectors to specify elements to add javascript events to. This means that instead of writing:

<li>
   <a onclick="this.parentNode.removeChild(this)" href="#">
      Click me to delete me
   </a>
</li>

You can use:

<ul id="example">
   <li>
      <a href="/someurl">Click me to delete me</a>
   </li>
</ul>

And then use css selectors to select that element and add javascript functions to it.

var myrules = {
   '#example li' : function(el){
      el.onclick = function(){
         this.parentNode.removeChild(this);

Usage

In your code you create a "rules" object, with sub-objects for each html element class name or id:

var myrules = {
   '.classname' : function(element) {
      // element event
      element.onclick = function() {
         // code here
      }
   },

Or use nested identifiers:

var myrules = {
   '.menu li a' : function(element) {
      element.onclick = function() {
         // code here
      }
   }
};

Apply the rules with:

Behaviour.register(myrules);

Example

<div id="demoblock" style="padding:1em; width:100px; text-align:center;">
MOUSE OVER ME
</div>

<script type="text/javascript">
// <![CDATA[
var myrules = {
   '#demoblock' : function(el) {
      var defaultColor = '#A3D6F8';
      var highlightColor = '#4A7FB5';
      
      el.style.backgroundColor = defaultColor;
      
      el.onmouseover = function() {
         this.style.backgroundColor = highlightColor;
         return false;
      }
      el.onmouseout = function() {
         this.style.backgroundColor = defaultColor;
         return false;
      }
   },
   '#demoblock span' : function(el) {
      
      var text = el.innerHTML;
      
      var fisherYates = function (inArray) {
        var i = inArray.length;
        if ( i == 0 ) return false;
        while ( --i ) {
          var j = Math.floor( Math.random() * ( i + 1 ) );
          var tempi = inArray[i];
          var tempj = inArray[j];
          inArray[i] = tempj;
          inArray[j] = tempi;
         }
      }
      
      var randomize = function(inText) {
         var letters = inText.split('');
         fisherYates(letters);
         return letters.join('');
      }
      el.onmouseover = function() {
         this.innerHTML = randomize(text);
         return false;
      }
      el.onmouseout = function() {
         this.innerHTML = text;
         return false;
      }
   }
};
Behaviour.register(myrules);
// ]]>
</script>

var myrules = {
   'table.test td' : function(element) {
      element.onmouseover = function() {
         this.style.backgroundColor = highlightColor;
         return false;
      }
      element = null; // by setting this IE will not leak  
   }
};   
Behaviour.register(myrules);

Development

• Google Groups: Behaviour Javascript Library
• Nabble - Behaviour Javascript Library forum & mailing list archive
• Behaviour2 - update in the making, since 2006

License

Links

• Behaviour website
• Behaviour Google Group

Installation Instructions

Like many other TWiki extensions, this module is shipped with a fully automatic installer script written using the BuildContrib.

• If you have TWiki 4.2 or later, you can install from the configure interface (Go to Plugins->Find More Extensions)
  • See the installation supplement on TWiki.org for more information.
• If you have any problems, then you can still install manually from the command-line:
  1. Download one of the .zip or .tgz archives
  2. Unpack the archive in the root directory of your TWiki installation.
  3. Run the installer script ( perl <module>_installer )
  4. Run configure and enable the module, if it is a plugin.
  5. Repeat for any missing dependencies.
• If you are still having problems, then instead of running the installer script:
  1. Make sure that the file permissions allow the webserver user to access all files.
  2. Check in any installed files that have existing ,v files in your existing install (take care not to lock the files when you check in)
  3. Manually edit LocalSite.cfg to set any configuration variables.

Contrib Settings

Contrib Info