dijit/form/_RadioButtonMixin.js

Dijit provides a complete collection of user interface controls based on Dojo, giving you the power to create web applications that are highly optimized for usability, performance, internationalization, accessibility, but above all deliver an incredible u

define([
	"dojo/_base/array", // array.forEach
	"dojo/_base/declare", // declare
	"dojo/dom-attr", // domAttr.set
	"dojo/_base/lang", // lang.hitch
	"dojo/query!css2", // query
	"../registry"    // registry.getEnclosingWidget
], function(array, declare, domAttr, lang, query, registry){

	// module:
	//		dijit/form/_RadioButtonMixin

	return declare("dijit.form._RadioButtonMixin", null, {
		// summary:
		//		Mixin to provide widget functionality for an HTML radio button

		// type: [private] String
		//		type attribute on `<input>` node.
		//		Users should not change this value.
		type: "radio",

		_getRelatedWidgets: function(){
			// Private function needed to help iterate over all radio buttons in a group.
			var ary = [];
			query("input[type=radio]", this.focusNode.form || this.ownerDocument).forEach(// can't use name= since query doesn't support [] in the name
				lang.hitch(this, function(inputNode){
					if(inputNode.name == this.name && inputNode.form == this.focusNode.form){
						var widget = registry.getEnclosingWidget(inputNode);
						if(widget){
							ary.push(widget);
						}
					}
				})
			);
			return ary;
		},

		_setCheckedAttr: function(/*Boolean*/ value){
			// If I am being checked then have to deselect currently checked radio button
			this.inherited(arguments);
			if(!this._created){
				return;
			}
			if(value){
				array.forEach(this._getRelatedWidgets(), lang.hitch(this, function(widget){
					if(widget != this && widget.checked){
						widget.set('checked', false);
					}
				}));
			}
		},

		_getSubmitValue: function(/*String*/ value){
			return value == null ? "on" : value;
		},

		_onClick: function(/*Event*/ e){
			if(this.checked || this.disabled){ // nothing to do
				e.stopPropagation();
				e.preventDefault();
				return false;
			}

			if(this.readOnly){ // ignored by some browsers so we have to resync the DOM elements with widget values
				e.stopPropagation();
				e.preventDefault();
				array.forEach(this._getRelatedWidgets(), lang.hitch(this, function(widget){
					domAttr.set(this.focusNode || this.domNode, 'checked', widget.checked);
				}));
				return false;
			}

			// RadioButton has some unique logic since it must enforce only a single button being checked at once
			// For this reason the "_onClick" method does not call this.inherited

			var canceled = false;
			var previouslyCheckedButton;

			array.some(this._getRelatedWidgets(), function(radioButton){
				if(radioButton.checked){
					previouslyCheckedButton = radioButton;
					return true;
				}
				return false;
			});

			// We want to set the post-click values correctly for any event handlers, but since
			// the event handlers could revert them, we don't want to fully update the widget state
			// yet and trigger notifications
			this.checked = true;
			previouslyCheckedButton && (previouslyCheckedButton.checked = false);

			// Call event handlers
			// If event handler prevents it, the clicked radio button will not be checked
			if(this.onClick(e) === false || e.defaultPrevented){
				canceled = true;
			}

			// Reset internal state to how it was before the click
			this.checked = false;
			previouslyCheckedButton && (previouslyCheckedButton.checked = true);

			if(canceled){
				e.preventDefault();
			}else{
				this.set('checked', true);
			}

			return !canceled;
		}
	});
});