Awesome
revalidator 
A cross-browser / node.js validator with JSONSchema compatibility as the primary goal.
Example
The core of revalidator is simple and succinct: revalidator.validate(obj, schema):
var revalidator = require('revalidator');
console.dir(revalidator.validate(someObject, {
properties: {
url: {
description: 'the url the object should be stored at',
type: 'string',
pattern: '^/[^#%&*{}\\:<>?\/+]+$',
required: true
},
challenge: {
description: 'a means of protecting data (insufficient for production, used as example)',
type: 'string',
minLength: 5
},
body: {
description: 'what to store at the url',
type: 'any',
default: null
}
}
}));
This will return with a value indicating if the obj conforms to the schema. If it does not, a descriptive object will be returned containing the errors encountered with validation.
{
valid: true // or false
errors: [/* Array of errors if valid is false */]
}
In the browser, the validation function is exposed on window.validate by simply including revalidator.js.
Installation
Installing npm (node package manager)
$ curl http://npmjs.org/install.sh | sh
Installing revalidator
$ [sudo] npm install revalidator
Usage
revalidator takes json-schema as input to validate objects.
revalidator.validate (obj, schema, options)
This will return with a value indicating if the obj conforms to the schema. If it does not, a descriptive object will be returned containing the errors encountered with validation.
{
valid: true // or false
errors: [/* Array of errors if valid is false */]
}
Available Options
- validateFormats: Enforce format constraints (default true)
- validateFormatsStrict: When
validateFormatsis true treat unrecognized formats as validation errors (default false) - validateFormatExtensions: When
validateFormatsis true also validate formats defined invalidate.formatExtensions(default true) - additionalProperties: When
additionalPropertiesis true allow additional unvisited properties on the object. (default true) - cast: Enforce casting of some types (for integers/numbers are only supported) when it's possible, e.g.
"42" => 42, but"forty2" => "forty2"for theintegertype.
Schema
For a property an value is that which is given as input for validation where as an expected value is the value of the below fields
required
If true, the value should not be undefined
{ required: true }
allowEmpty
If false, the value must not be an empty string
{ allowEmpty: false }
type
The type of value should be equal to the expected value
{ type: 'string' }
{ type: 'number' }
{ type: 'integer' }
{ type: 'array' }
{ type: 'boolean' }
{ type: 'object' }
{ type: 'null' }
{ type: 'any' }
{ type: ['boolean', 'string'] }
pattern
The expected value regex needs to be satisfied by the value
{ pattern: /^[a-z]+$/ }
maxLength
The length of value must be greater than or equal to expected value
{ maxLength: 8 }
minLength
The length of value must be lesser than or equal to expected value
{ minLength: 8 }
minimum
Value must be greater than or equal to the expected value
{ minimum: 10 }
maximum
Value must be lesser than or equal to the expected value
{ maximum: 10 }
allowEmpty
Value may not be empty
{ allowEmpty: false }
exclusiveMinimum
Value must be greater than expected value
{ exclusiveMinimum: 9 }
exclusiveMaximum
Value must be lesser than expected value
{ exclusiveMaximum: 11 }
divisibleBy
Value must be divisible by expected value
{ divisibleBy: 5 }
{ divisibleBy: 0.5 }
minItems
Value must contain more than expected number of items
{ minItems: 2 }
maxItems
Value must contain fewer than expected number of items
{ maxItems: 5 }
uniqueItems
Value must hold a unique set of values
{ uniqueItems: true }
enum
Value must be present in the array of expected values
{ enum: ['month', 'year'] }
format
Value must be a valid format
{ format: 'url' }
{ format: 'email' }
{ format: 'ip-address' }
{ format: 'ipv6' }
{ format: 'date-time' }
{ format: 'date' }
{ format: 'time' }
{ format: 'color' }
{ format: 'host-name' }
{ format: 'utc-millisec' }
{ format: 'regex' }
conform
Value must conform to constraint denoted by expected value
{ conform: function (v) {
if (v%3==1) return true;
return false;
}
}
dependencies
Value is valid only if the dependent value is valid
{
town: { required: true, dependencies: 'country' },
country: { maxLength: 3, required: true }
}
Nested Schema
We also allow nested schema
{
properties: {
title: {
type: 'string',
maxLength: 140,
required: true
},
author: {
type: 'object',
required: true,
properties: {
name: {
type: 'string',
required: true
},
email: {
type: 'string',
format: 'email'
}
}
}
}
}
Custom Messages
We also allow custom messages for different constraints
{
type: 'string',
format: 'url'
messages: {
type: 'Not a string type',
format: 'Expected format is a url'
}
{
conform: function () { ... },
message: 'This can be used as a global message'
}
Tests
All tests are written with vows and should be run with npm:
$ npm test