How to get value checkbox in doCLick event?

$("CheckBox", "choice",
                                {
                                    row: 2,
                                    column: 0,
                                    "Button.width": 20,
                                    "Button.height": 20,
                                    "ButtonBorder.figure": "Circle",
                                    "ButtonBorder.stroke": "blue",
                                    "ButtonIcon.figure": "Circle",
                                    "ButtonIcon.fill": "blue",
                                    "ButtonIcon.strokeWidth": 0,
                                    "ButtonIcon.desiredSize": new go.Size(10, 10)
                                },
                                $(go.TextBlock, "is hidden"),
                                {
                                    "_doClick": function (e, obj) {
                                        console.log(obj);
                                    }
                                }
                            ),

How did you define your “CheckBox”? The second argument should be the name of the data property that will be toggled. So maybe something like: obj.part.data.choice.

See the complete definition of the “CheckBox” builder at http://gojs.net/latest/extensions/Buttons.js.

See examples at CheckBoxes.

obj.part.data.option1 - undefined