[SalesForce] maxlength attribute not working in lightning:input for number type

({
    limitCharacterTo : function(element, charLimit, evt) {
        var charCode = (evt.which) ? evt.which : event.keyCode;
        if(element.value.length >= charLimit && charCode != 8) {
           return false;
        }
    }
})

I haven't tried this in lightning, but if you can bind this to the aura:id field, you can call this function on keypress and pass in the desired parameters.

helper.getAccount is asynchronous. This means that until your init method has finished, myAccount will definitely be a null value, as you haven't had a chance to visit the server yet. You'll need to set mapMarkers after you've had a chance to load the data from the server. You'll want to read about how to Write Asynchronous JavaScript for more information on how you can simplify your code.