instantiate drawing programatically

[cscrum]

I am needing to draw a rectangle on the map without having to press a button. I'm having difficulty figuring out how to put the map into drawing mode without the button. I've tried based on examples from leaflet-draw, but nothing seems to be working for me. Is there a way to enable the drawing mode to add a rectangle programatically?

[cscrum]

I have tried this based on other issues here, but I keep getting an error.
setRectmode(){
var self = this;
var shapeOptions = {
stroke: true,
color: '#f06eaa',
weight: 4,
opacity: 0.5,
fill: true,
fillColor: null, //same as color by default
fillOpacity: 0.2,
clickable: true,
editable: true
};
var rectDraw = new (L as any).Draw.Rectangle(self.map, shapeOptions); <<<error here
rectDraw.enable();
this.drawnItems.addLayer(rectDraw);
}

ERROR TypeError: Cannot read property 'Rectangle' of undefined

  I've also tried changing the line where the error occurs to this
  var rectDraw = new (L as any).Rectangle(self.map, shapeOptions);

  ERROR TypeError: Cannot read property 'lat' of undefined

Any pointers as to what I might be doing wrong? The goal is to put the map into a mode where I can draw a rectangle on the map.