validate.js
function(value, options) {
      options = v.extend({}, this.options, options);
      if (options.allowEmpty !== false ? !v.isDefined(value) : v.isEmpty(value)) {
        return options.message || this.message || "can't be blank";
      }
    }
function(value, options) {
      options = v.extend({}, this.options, options);
      if (options.allowEmpty !== false ? !v.isDefined(value) : v.isEmpty(value)) {
        return options.message || this.message || "can't be blank";
      }
    }
function ( value , options ) { options = v . extend ( { } , this . options , options ) ; if ( options . allowEmpty !== false ? ! v . isDefined ( value ) : v . isEmpty ( value ) ) { return options . message || this . message || "can't be blank" ; } }
Presence validates that the value isn't empty
Presence validates that the value isn t empty