A simple AngularJS directive to make sure a number is not zero. It sets the formName.elementName.$error.zero value accordingly.

notZero.js

/**
 * @description A simple check to ensure a number is not zero. Sets the "zero" validation accordingly.
 * @usage <input ng-model="myModel" not-zero>
 */
angular.module("app").directive("notZero", function() {

    var linkFunc = function(scope, element, attrs, ngModel) {

        var zeroValidator = function(value) {
            var num = parseFloat(value);
            ngModel.$setValidity("zero", ! isNaN(num) && num !== 0);
            return value;
        };

        ngModel.$parsers.push(zeroValidator);
        ngModel.$formatters.push(zeroValidator);

    };

    return {
        require: "ngModel",
        link: linkFunc
    };

});