防止用户在需要验证的文本字段中输入null

Question

Is there a way to tell knockout that if a user typing null in a required textfield it will not be valid.

This will just force user to type anything but whitespaces.

ko.observable().extend({ required: true });

EDIT:

I've tried this without any success:

self.test = ko.observable().extend({ validation: { validator: self.notNullOrEmpty, message: '' } });

self.notNullOrEmpty = function (val) {
   return val != 'null' || val != '';
};

Exception:

http://localhost:50566/Scripts/knockout.validation.js

0x800a138f - JavaScript runtime error: Object expected

Answer 1

Try this custom validation.

ko.validation.rules['notNullOrEmpty'] = {
  validator: function (val) {
    return ko.validation.utils.isEmptyVal(val) || val !== 'null';
  },
  message: 'invalid input'
};
ko.validation.registerExtenders();

Fiddle Demo