Dojo TypeScript extension test. Output js files compiled using: tsc -m amd test.ts

dojo-test.d.ts

declare module "dijit/layout/ContentPane" {
    class ContentPane {
        // define methods etc. here
    }
    export = ContentPane;
}

LayerStylePane.js

/// <reference path="./dojo-test"/>
var __extends = this.__extends || function (d, b) {
    for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
    function __() { this.constructor = d; }
    __.prototype = b.prototype;
    d.prototype = new __();
};
define(["require", "exports", "dijit/layout/ContentPane"], function(require, exports, ContentPane) {
    

    var LayerStylePane = (function (_super) {
        __extends(LayerStylePane, _super);
        function LayerStylePane() {
            _super.apply(this, arguments);
        }
        LayerStylePane.prototype.addSymbol = function (label, symbol) {
            // impl here
        };
        return LayerStylePane;
    })(ContentPane);
    return LayerStylePane;
});

LayerStylePane.ts

/// <reference path="./dojo-test"/>

import ContentPane = require("dijit/layout/ContentPane");

export = LayerStylePane;

class LayerStylePane extends ContentPane {
    addSymbol(label: string, symbol: any) {
        // impl here
    }
}

test.js

define(["require", "exports", "./LayerStylePane"], function(require, exports, LayerStylePane) {
    var myPane = new LayerStylePane();
    myPane.addSymbol("test", {});
});

test.ts

import LayerStylePane = require("./LayerStylePane");

var myPane = new LayerStylePane();
myPane.addSymbol("test", {});

I was able to create a LayerStylePane from via parser.parse as well as dynamically. Not only that, I was able to do this:

var x: typeof LayerStylePane;
var y = new x({}, null);

Why was I under the impression you could not extend a dijit class? How would this work with a templated mixin?

Regarding the namespace aspect of this question, How would this code extend _Widget? How do you get a reference to it since it's within the "dijit/_Widget" module.

declare module "dijit/layout/ContentPane" {
class ContentPane extends dijit._Widget {
// define methods etc. here
}
export = ContentPane;
}

dojo-test.d.ts

declare module "dijit/_WidgetBase" {
    class _WidgetBase {
    }
    export = _WidgetBase;
}

declare module "dijit/layout/ContentPane" {
    import _WidgetBase = require("dijit/_WidgetBase");
    class ContentPane extends _WidgetBase {
        // define methods etc. here
    }
    export = ContentPane;
}

To use extends under 0.9.5, you'd need the style:

declare module "dijit/foo"
{
    class foo extends dijit._WidgetBase {}
    export = foo;
}

The style I use won't allow it:

declare module "dijit/foo"
{
    var foo : typeof dijit._WidgetBase;
    export = foo;
}

But there are a lot of places to change.