Sencha Touch - add KeyDown event on NumberField

Question

I've been banging my head against the wall for days trying to get a KeyPress or a KeyDown event to fire on a Sencha Touch textfield.

I'm trying to accomplish two things: 1) Limit the max length to 3 and 2) Ensure that the user is entering only numbers (no letters or special chars)

Is there no way using Javascript to attach these events? I'm using Sencha 2.3.1

Update: I've tried using numberfield and also using maxLength...neither work.

   var numberfield = 
    {
        xtype: 'numberfield',
        value: textValue,
        readOnly: true,
        cls: 'opBuyoffPartialCell',
        inputCls: 'opBuyoffCenterText',
        maxLength: 3,
        enforceMaxLength: 3
    };

Answer 1

As @MonicaOlejniczak wrote, use a numberfield.

If you don't want to use a numberfield, at least have a look at its code and find that Sencha uses

this.getComponent().input.dom.setAttribute("type", "number");

to ensure that the user can only input numbers. That way, the "number" ,,,, which your code would allow, will also be taken care of.

To ensure a maxLength, sencha already has maxLength config which is available on both the numberfield and the textfield.