Backbone.viewOptions

A mini Backbone.js plugin to declare and get/set options on views.

Benefits

• Use a simple declarative syntax to attach white-listed initialization options directly to your views.
• Optionally define default values for options, and assert that required options are supplied.
• Can be mixed into any view class.

Usage

// Add the view options functionality to all our views.
Backbone.ViewOptions.add( Backbone.View.prototype );

ButtonView = Backbone.View.extend( {
	options : [ "label" ],

	initialize : function( options ) {
		this.setOptions( options );  // set the view's options from initialization options.

		// Options that are white-listed in the view's `options`
		// property are now attached to the view object.
		console.log( this.label );
	}
} );

// Outputs "OK" to the console.
myButtonView = new ButtonView( { "label" : "OK" } );

// Another example showing default values and required options.
WidgetView = Backbone.View.extend( {
	options : [
		{ "label" : "OK" },  // Use this object syntax to give an option a default value.
		"type!"  // Use a trailing exclamation mark to indicate that an option is required.
	],

	initialize : function( options ) {
		this.setOptions( options );
	},

	render : function() {
		console.log( this.label );
	}
} );

// Outputs "OK" to the console (because the "label" option defaults to "OK").
myWidgetView = new WidgetView( { "type" : "button" } ).render();

// Throws an exception (because the required "type" option is missing).
myOtherWidgetView = new WidgetView( { "label" : "Cancel" } ).render();

Methods and Properties

Backbone.ViewOptions.add( view, [ optionsDeclarationsProperty ] )

Initialize the view plugin on a view class or instance. Backbone.ViewOptions.add( Backbone.View.prototype ) will make the plugin available on all backbone views. optionsDeclarationsProperty specifies which view property holds the options declarations array and defaults to "options". (If using Backbone < 1.1.0, specify another value to as these older version of Backbone conflict with view.options.)

view.options

An "option declarations" array should be supplied as the options property of the view class (or as the optionsDeclarationsProperty property). Each element in the array must be a string or an object.

• A string element simply white-lists the name of an option that should be attached to the view when it is supplied in view.setOptions()'s optionsHash (see below). The name may optionally be followed by an exclamation mark, which indicates a "required" option.
• An object element may be used to give an option a default value, the key of the object being the option's name and the value its default value.

You may alternatively supply a function that returns an array, very much like how you may supply a function that returns a hash for the built-in backbone view.events property.

view.setOptions( optionHash )

Sets the view's options to the values in optionHash as appropriate. If a "required" option is not supplied (and not already on the view) an exception is raised.

view.getOptions()

Returns a hash mapping all option names to current values.

view.onOptionsChanged( newValues, previousValues ) callback

This method, if it exists on a view, is called when option(s) that are already present on the view object are changed via view.setOptions(). newValues and previousValues are hashes of the changed options to their new and old values respectively. This method also has an alias, _onOptionsChanged.

Requirements / Compatibility

• Backbone 1.0.0 or later
• Underscore

Change log

0.2.0

• Changed view.getOptionsNames() to view.getOptions()
• Added support for underscored view._onOptionsChanged
• Added optionsDeclarationsProperty argument to support Backbone < 1.1.0

0.1.0

• Initial release