A rectangle with an HTML label (with a fallback to SVG label for IE).

Supported `attrs` properties

Selector | Node | Description
--- | --- | ---
root | SVGGElement | Container of all nodes
body | SVGRectElement | Rectangular body of the shape
label | HTMLDivElement | Text inside the body

    var textBlock = new joint.shapes.tandard.TextBlock();
    textBlock.resize(100, 100);
    textBlock.position(250, 610);
    textBlock.attr('root/title', 'joint.shapes.standard.TextBlock');
    textBlock.attr('body/fill', 'lightgray');
    textBlock.attr('label/text', 'Hyper Text Markup Language');
    // Styling of the label via `style` presentation attribute (i.e. CSS).
    textBlock.attr('label/style/color', 'red');
    textBlock.addTo(graph);