Question

Is there any way to catch the event if the value inside dijit.form.NumberSpinner widget gets incremented or decremented?

What I intent to do is whenever value goes below 0 set text inside NumberSpinner widget as “Never” and when user increments it from “Never” it should be again set to 0.

Answer 1

dojo.declare("MySpinner", [Spinner], {

    zeroValue: 'Never',

    adjust: function(/*Object*/ val, /*Number*/ delta){
        arguments[0] = val && val > 0 ? val : 0;
        return this.inherited(arguments);
    },

    _getValueAttr: function() {
      var v = this.inherited(arguments);
      return (!v || v <= 0) ? 0 : v;
    },

    format: function(/*Number*/ value, /*dojo.number.__FormatOptions*/ constraints){
      var v = this.inherited(arguments);
      if (v <= 0 || !v) 
         return this.zeroValue;

      return v;
    },

    isValid: function(/*Boolean*/ isFocused){
        var v = this.get('value');
        if (!v) {
            return true;
        }           
        return this.inherited(arguments);
    }
});  

Here’s the working example

http://jsfiddle.net/cswing/zDVep/