INTRODUCTION
============

Development with MKWS consists primarily of defining new types of
widgets. These can interact with the core functionality is several
defined ways.

You create a new widget type by calling the mkws.registerWidgetType
function, passing in the widget name and a function. The name is used
to recognise HTML elements as being widgets of this type -- for
example, if you register a "Foo" widget, elements like <div
class="mkwsFoo"> will be widgets of this type.

The function promotes a bare widget object (passed as `this') into a
widget of the appropriate type. MKWS doesn't use classes or explicit
prototypes: it just makes objects that have the necessary
behaviours. Widgets have *no* behaviours that they have to provide:
you can make a doesn't-do-anything-at-all widget if you like:

	mkws.registerWidgetType('Sluggard', function() {});

More commonly, widgets will subscribe to one or more events, so that
they're notified when something interesting happens. For example, the
"Log" widget asks to be notified when a "log" event happens, and
appends the logged message to its node, as follows:

	mkws.registerWidgetType('Log', function() {
	    var that = this;

	    this.team.queue("log").subscribe(function(teamName, timestamp, message) {
		$(that.node).append(teamName + ": " + timestamp + message + "<br/>");
	    });
	});

This simple widget illustrates several important points:

* The base widget object (`this') has several baked-in properties and
  methods that are available to individual widgets. These include
  this.team (the team that this widget is a part of) and this.node
  (the DOM element of the widget).

* The team object (`this.team') also has baked-in properties and
  methods. These include the queue function, which takes an event-name
  as its argument. It's possible to subscribe to an event's queue
  using this.team.queue("EVENT").subscribe. The argument is a function
  which is called whenever the event is published. The arguments to
  the function are different for different events.

* The value of `this' is lost inside the subscribe callback, so it
  must be saved if it's to be used inside that callback (typically as
  a local variable named `that').


SPECIALISATION (INHERITANCE)
============================

Many widgets are simple specialisations of existing widgets. For
example, the "Record" widget is the same as the "Records" widget
except that it defaults to displaying a single record. It's defined as
follows:

	mkws.registerWidgetType('Record', function() {
	    mkws.promotionFunction('Records').call(this);
	    if (!this.config.maxrecs) this.config.maxrecs = 1;
	});

Remember that when a promotion function is called, it's passed a base
widget object that's not specialised for any particular task. To make
a specialised widget, first promote that base widget into the type
that you want to specialise from -- in this case, "Records" -- using
the promotion function that's been registered for that type.

Once this has been done, the specialisations can be introduced. In
this case, it's a very matter of changing the "maxrecs" configuration
setting to 1 unless it's already been given an explicit value. (That
would occur if the HTML used an element like <div class="mkwsRecord"
maxrecs="2">, though it's not obvious why anyone would do that.