knockout-validation

Knockout validation and error handling module.

Usage

npm install --save knockout-validation

In your JavaScript code

As AMD

require(['knockout', 'knockout-validation'], function (ko, koValidation) {
  var ob = ko.observable().extend({
    validate: [
      // a list of validators
      koValidation.string(),
    ]
  });

  ob('foo'); // this will success
  ob(123); // this will fail
});

As CMD

var ko = require('knockout');
var koValidation = require('knockout-validation');

var ob = ko.observable().extend({
  validate: [
    // a list of validators
    koValidation.string(),
  ]
});

ob('foo'); // this will success
ob(123); // this will fail

API

koValidation.string()

Create a string validator verifies if the observable has a string value.

koValidation.string.size(length)

Create a string validator with limited length.

koValidation.string.xss()

Create a string validator with XSS (cross site scripting) check.

koValidation.number()

Create a number validator verifies if the observable has a number value.

koValidation.number.size(integerLength, decimalLength)

Create a number validator with limited integer part length and decimal part length.

koValidation.number.range(min, max)

Create a number validator with a range.

koValidation.enum(values, nullable)

Create an enum validator validates if the observable has a value in the given value set.

koValidation.required(allowSpace)

Create a validator verifies if the observable has a value. If allowSpace is false, space only strings are treated as invalid.

koValidation.custom(isValid, message, blockInput)

Create a validator using customized validation method.

• isValid, the validation method in form of function (value) { return true; }
• message, the error message for validation failure
• blockInput, a boolean decides whether invalid value will be blocked. If it's true, setting the observable with an invalid value will turn into a noop. Otherwise, the observable will be updated with the message added to the its errors property

koValidation.run(value, validators)

Validate a value against an array of validators manually. Returns the error message of the first failed validator

Validator.prototype.set(options)

For each validator, you can call its set method to config the following options

• blockInput, whether or not the invalid values are blocked from setting to the observable
• message, the error message on validation failure

Validator.prototype.validate(value)

Validate a given value directly. Returns the error message if failed, otherwise returns undefined.