From: Mike Taylor Date: Mon, 10 Nov 2014 16:59:55 +0000 (+0000) Subject: Rewrite "defining new kinds of widget" section. X-Git-Tag: 1.0.0~25 X-Git-Url: http://git.indexdata.com/?p=mkws-moved-to-github.git;a=commitdiff_plain;h=f15742ce1adcc967c50fb03b71bad68a55628c63 Rewrite "defining new kinds of widget" section. --- diff --git a/doc/mkws-developer.markdown b/doc/mkws-developer.markdown index 9d3ac4b..ffa831b 100644 --- a/doc/mkws-developer.markdown +++ b/doc/mkws-developer.markdown @@ -87,29 +87,30 @@ Defining new types of widget ---------------------------- Development with MKWS consists primarily of defining new types of -widgets. These can interact with the core functionality is several -defined ways. +widgets. This is done using exactly the same API as the the widgets +that come as part of the set: they have no privileged access. 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 -`
` will be widgets of this type. +example, if you register a `foo` widget, elements like +`
` will become widgets of this type. -The function promotes a bare widget object (passed as `this`) into a +The function promotes a bare widget object (which is created by the +core widget code and passed in 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. There are _no_ behaviours that Widgets are obliged to provide: you can make a doesn't-do-anything-at-all widget if you like: - mkws.registerWidgetType('Sluggard', function() {}); + 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 +`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() { + mkws.registerWidgetType('log', function() { var that = this; this.team.queue("log").subscribe(function(teamName, timestamp, message) { @@ -131,11 +132,11 @@ This simple widget illustrates several important points: * You can add functionality to a widget by subscribing it 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. + published. The arguments to the event-callback function are + different for different events. * As with so much JavaScript programming, the value of the special - variable `this` is lost inside the `subscribez` callback function, + variable `this` is lost inside the `subscribe` callback function, so it must be saved if it's to be used inside that callback (typically as a local variable named `that`).