source: Dev/trunk/src/client/dijit/form/_ButtonMixin.js

define([
        "dojo/_base/declare", // declare
        "dojo/dom", // dom.setSelectable
        "dojo/has",
        "../registry"        // registry.byNode
], function(declare, dom, has, registry){

        // module:
        //              dijit/form/_ButtonMixin

        var ButtonMixin = declare("dijit.form._ButtonMixin" + (has("dojo-bidi") ? "_NoBidi" : ""), null, {
                // summary:
                //              A mixin to add a thin standard API wrapper to a normal HTML button
                // description:
                //              A label should always be specified (through innerHTML) or the label attribute.
                //
                //              Attach points:
                //
                //              - focusNode (required): this node receives focus
                //              - valueNode (optional): this node's value gets submitted with FORM elements
                //              - containerNode (optional): this node gets the innerHTML assignment for label
                // example:
                // |    <button data-dojo-type="dijit/form/Button" onClick="...">Hello world</button>
                // example:
                // |    var button1 = new Button({label: "hello world", onClick: foo});
                // |    dojo.body().appendChild(button1.domNode);

                // label: HTML String
                //              Content to display in button.
                label: "",

                // type: [const] String
                //              Type of button (submit, reset, button, checkbox, radio)
                type: "button",

                __onClick: function(/*Event*/ e){
                        // summary:
                        //              Internal function to divert the real click onto the hidden INPUT that has a native default action associated with it
                        // type:
                        //              private
                        e.stopPropagation();
                        e.preventDefault();
                        if(!this.disabled){
                                // cannot use on.emit since button default actions won't occur
                                this.valueNode.click(e);
                        }
                        return false;
                },

                _onClick: function(/*Event*/ e){
                        // summary:
                        //              Internal function to handle click actions
                        if(this.disabled){
                                e.stopPropagation();
                                e.preventDefault();
                                return false;
                        }
                        if(this.onClick(e) === false){
                                e.preventDefault();
                        }
                        var cancelled = e.defaultPrevented;

                        // Signal Form/Dialog to submit/close.  For 2.0, consider removing this code and instead making the Form/Dialog
                        // listen for bubbled click events where evt.target.type == "submit" && !evt.defaultPrevented.
                        if(!cancelled && this.type == "submit" && !(this.valueNode || this.focusNode).form){
                                for(var node = this.domNode; node.parentNode; node = node.parentNode){
                                        var widget = registry.byNode(node);
                                        if(widget && typeof widget._onSubmit == "function"){
                                                widget._onSubmit(e);
                                                e.preventDefault(); // action has already occurred
                                                cancelled = true;
                                                break;
                                        }
                                }
                        }

                        return !cancelled;
                },

                postCreate: function(){
                        this.inherited(arguments);
                        dom.setSelectable(this.focusNode, false);
                },

                onClick: function(/*Event*/ /*===== e =====*/){
                        // summary:
                        //              Callback for when button is clicked.
                        //              If type="submit", return true to perform submit, or false to cancel it.
                        // type:
                        //              callback
                        return true;            // Boolean
                },

                _setLabelAttr: function(/*String*/ content){
                        // summary:
                        //              Hook for set('label', ...) to work.
                        // description:
                        //              Set the label (text) of the button; takes an HTML string.
                        this._set("label", content);
                        var labelNode = this.containerNode || this.focusNode;
                        labelNode.innerHTML = content;
                }
        });

        if(has("dojo-bidi")){
                ButtonMixin = declare("dijit.form._ButtonMixin", ButtonMixin, {
                        _setLabelAttr: function(){
                                this.inherited(arguments);
                                var labelNode = this.containerNode || this.focusNode;
                                this.applyTextDir(labelNode);
                        }
                });
        }

        return ButtonMixin;
});