` 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) {
@@ -83,11 +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`).
@@ -96,13 +145,13 @@ Widget 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:
+example, the `images` widget is the same as the `records` widget
+except that it defaults to using the `images` template for displaying
+its result list. It's defined as follows:
- mkws.registerWidgetType('Record', function() {
- mkws.promotionFunction('Records').call(this);
- if (!this.config.maxrecs) this.config.maxrecs = 1;
+ mkws.registerWidgetType('images', function() {
+ mkws.promotionFunction('records').call(this);
+ if (!this.config.template) this.config.template = 'images';
});
Remember that when a promotion function is called, it's passed a base
@@ -112,11 +161,11 @@ 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 simple 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 `
`, though it's not obvious why anyone
-would do that.)
+this case, it's a very simple matter of changing the `template`
+configuration setting to `'images'` unless it's already been given an
+explicit value. (That would occur if the HTML used an element like
+`
` to use a customised
+template.
Reference Guide
@@ -131,7 +180,8 @@ that is passed into `registerWidgetType`'s callback function, and can
be used by the derived widget.
* `String this.type` --
- A string containing the type of the widget.
+ A string containing the type of the widget (`search`,
+ `switch`, etc.)
* `Team this.team` --
The team object to which this widget belongs. The team has
@@ -139,7 +189,8 @@ be used by the derived widget.
below.
* `DOMElement this.node` --
- The DOM element of the widget
+ The DOM element of the widget. Most often used for inserting
+ HTML into the widget element.
* `Hash this.config` --
A table of configuration values for the widget. This table
@@ -148,7 +199,7 @@ be used by the derived widget.
inherits from the default configuration. Instances of widgets
in HTML can set configuration items as HTML attributes: for
example, the HTML element
- `
`.
+ `
`
creates a widget for which `this.config.maxrecs` is set to 10.
* `String this.toString()` --
@@ -170,16 +221,6 @@ be used by the derived widget.
widgets such as `Records` and `Facet` that display some part
of a search result.
-* `VOID hideWhenNarrow()` --
- Registers that this widget should hide itself when the page
- becomes "narrow" -- that is, fewer pixels in width that the
- threshhold value specified by the top-level configuration item
- `responsive_design_width`. Should be used for "unimportant"
- widgets that can be omitted from the mobile version of a site.
-
-* `expandValue()` --
- TODO: either document this or remove it from the API.
-
* `subwidget(type, overrides, defaults)` --
Returns the HTML of a subwidget of the specified type, which
can then be inserted into the widget using the
@@ -188,20 +229,15 @@ be used by the derived widget.
except where overrides are passed in. If defaults are also
provided, then these are used when the parent widget provides
no values. Both the `overrides` and `defaults` arguments are
- hashes: the latter is optional.
-
- See for example the `Credo` widget defined in the example
- area's `mkws-widget-credo.js` file. This uses several
- invocations of `subwidget` to create a complex compound widget
- with numerous text, facet and image panes. TODO: rename this
- widget and everything related to it.
+ hashes: the latter is optional. This can be used to assemble
+ compound widgets containing several subwidgets.
In addition to these properties and methods of the bare widget object,
some kinds of specific widget add other properties of their own. For
-example, the `Builder` widget uses a `callback` property as the
+example, the `builder` widget uses a `callback` property as the
function that it use to publish the widget definition that it
constructs. This defaults to the builtin function `alert`, but can be
-overridden by derived widgets such as `ConsoleBuilder`.
+overridden by derived widgets such as `console-builder`.
Team methods
@@ -282,7 +318,7 @@ API should get simpler.
Events
------
-TODO: list of events that can be usefully subscribed to.
+FIXME: list of events that can be usefully subscribed to.
- - -