jski

jski - json schema validator
============================

JSON Schema support
-------------------
jski validates a subset of json schema v4. Following features are missing or restricted:

* no union types
* array: additionalItems can only be true or false, not a schema
* object: additionalProperties can only be true or false
* object: no patternProperties
* object: no dependencies
* $ref: definitions are solely looked up by name in options.definitions or jski.object({...}).defintions({...})
* not: not supported

Installation
------------

npm install jski

Usage
-----

var J = require('jski')();

Examples
--------

$3

``javascript

var J = require('jski')();

var validator = J.object({
foo: J.number(),
bar: J.string().maxLength(255)
});

var errs = validator.validate({ foo: 11, bar: 'hello' });

`

$3

`javascript

var J = require('jski')();

var js = {
foo: { type: 'number' },
bar: { type: 'string', maxLength: 255 }
};

var validator = J.createValidator(js);

var errs = validator.validate({ foo: true, bar: 'hello' });

`

$3

`javascript

var J = require('jski')();

var json = J.object({ foo: J.string() }).toJSON();

`

API
---

$3

#### Types

* J.boolean()
* J.number().minimum(1).maximum(10).multipleOf()
* J.integer() - Same as number
J.string().minLength(1).maxLength(10).pattern('[0-9]').format('email')
* J.array(J.number()).minItems(1).maxItems(10).uniqueItems(true).additionalItems(false)
* J.array(J.number(), J.string(), J.boolean())
* J.object({ foo: J.number() }).minProperties(1).maxProperties(10).required('foo', 'bar').additionalProperties(false)
* J.enum(1, 2, 3)
* J.any()
* J.null()
* J.allOf(schema1, schema2, schema3)
* J.anyOf(schema1, schema2, schema3)
* J.oneOf(schema1, schema2, schema3)

#### Common methods available to all types

* J.number().title('foo').description('bar').default(11)

$3

validate(value, options) returns an error array. When the value is valid, the array is empty.

* var errors = J.number().maximum(127).validate(128)

$3

Add Defintions:

* by method: J.object({...}).definitions({...})
* by options: var errors = J.object({...}).validate({...}, { definitions: {...} })

$3

* J.createValidator(Schema JSON)
* J.object({ foo: j.string() }).toJSON()

$3

* J.createValue(J.number())
* J.createValue({ type: 'number' })

$3

J.object().validate(value, { definitions: defs, omitRefs: true })

* definitions - Dict where $refs are lookuped by name
* omitRefs - Do not validate $refs

$3

Simple way to reuse definitions without using an actual $ref

`javascript
var validator = J
.mixin('foo', J.object({ bar: J.string() }))
.mixin('bar', J.object({ baz: J.number() }))
.object({
un: J.foo(),
dos: J.bar()
});
`

$3

`javascript
var J = require('jski)();
var v1 = J.object({ foo: J.string() });
assert(v1.context === J);
`

$3

Error messages look like:

{ message: "Value is too long", code: "maxLength", path: "foo.bar[0].baz" }`