Ova-browser NPM

Ova-browser

A browser-friendly version of Ova! Ova is an Object VAlidator that is light, extensible, and schema-based.

The Node.js version of Ova can be found here

What's New In 1.2.0

Added 'eq' rule to check for string/number equality

Installation

$ npm install ova-browser

Usage

First, model a schema of the object you want to validate. Then, call ova and see if it returns an error or null.

var ova = require('ova');

var movie = {
	title: '300',
	crew: {
		director: 'Zack Snyder',
		writers: ['Frank Miller', 'Zack Snyder']
	}
};

var movieSchema = {
	title: { _rules: { type: 'string' } },
	crew: {
		director: { _rules: { type: 'string' } },
		writers: { _rules: { type: 'array', arrayType: 'string' } }
	}
};

var error = ova(movie, movieSchema);

if (error != null) {
	console.log(error);
}

The _rules Object

Add all the rules that apply to a property in the _rules object in the schema.

var schema = {
	title: { _rules: { type: 'string' } },
	rating: { _rules: { type: 'number', required: true, null: false, min: 1, max: 10 } }
};

The Return Object

If there are no errors, ova() returns null.

If there are errors, she returns an object with each property that failed validation and the reason why.

var movie2 = {
	title: 300,
	crew: {
		director: 'Zack Snyder',
		writers: 'Frank Miller, Zack Snyder'
	}
};

var error = ova(movie2, movieSchema);

if (error != null) {
	console.log(error);
}

Output:

{
	title: 'Invalid type',
	crew: {
		writers: 'Invalid type'
	}
}

Rules

The following are keys you can use in the _rules object in your schema.

Rule precedence: If you have required and/or null rules, required will be evaluated first, then null, then any other rule.

Rule skip: Rules will not be evaluated if the property value is undefined. The exception is the required rule.

required

Data type: boolean

If true, property must be defined. If false, property can be undefined.

var schema = {
	title: { _rules: { required: true } }
};

Note: Setting this rule to false is logically the same as not using it at all.

null

Data type: boolean

If true, property can be null. If false, property cannot be null.

var schema = {
	rating: { _rules: { null: true } }
};

Note: required and null rules can coexist together.

type

Data type: string

Checks if property is of the specified type.

Possible values	Notes
array
boolean
date	Checks if property is a JavaScript Date object
dateString	Checks if property can be parsed with `Date.parse()`
jsonString	Checks if property can be parsed with `JSON.parse()`
number
numberString
string

var schema = {
	rating: { _rules: { type: 'number' } }
};

arrayType

Data type: string

Checks if an array's elements are of the specified type.

See type for possible values.

var schema = {
	writers: { _rules: { type: 'array', arrayType: 'string' } }
};

eq

Data type: string, number

Checks if property is equal to specified target.

var schema = {
	title: { _rules: { type: 'string', eq: '300' } },
	rating: { _rules: { type: 'number', eq: 1 } }
};

Important: Does not work for arrays and objects

min

Data type: number

Checks if property is equal to or greater than the specified number.

var schema = {
	rating: { _rules: { type: 'number', min: 1 } }
};

max

Data type: number

Checks if property is equal to or less than the specified number.

var schema = {
	rating: { _rules: { type: 'number', max: 10 } }
};

minLength

Data type: number

Checks if array/string has a length equal to or greater than the specified number.

var schema = {
	name: { _rules: { type: 'string', minLength: 1 } },
	writers: { _rules: { type: 'array', arrayType: 'string', minLength: 1 } }
};

maxLength

Data type: number

Checks if array/string has a length equal to or less than the specified number.

var schema = {
	name: { _rules: { type: 'string', maxLength: 100 } },
	writers: { _rules: { type: 'array', arrayType: 'string', maxLength: 10 } }
};

enum

Data type: array

If property is a single-value, checks if it is one of the enumerated values. If property is an array, checks if each of its elements is one of the enumerated values.

var schema = {
	director: { _rules: { type: 'string', enum: ['Zack Snyder', 'JJ Abrams'] } },
	cast: { _rules: { type: 'array', enum: ['Gerald Butler', 'Lena Headey', 'Michael Fassbender'] } }
};

regex

Data type: regular expression

Checks if property matches the specified regular expression.

var schema = {
	email: { _rules: { regex: /.+@.+/ } }
};

Custom Validators

You can add your own custom validator functions to ova, and use it in the _rules object in your schema.

ova.add(rule, fn)

Arguments:

rule (string): Name of the rule
fn (function): Validator function

The validator function must have a signature of function(val, ruleVal) where val is the value of the property of the object we are validating and ruleVal is the value of the rule.

var fn = function(val, ruleVal) {
	return (val !== ruleVal ? null : 'Value is disallowed');
};

ova.add('disallow', fn);

var person = {
	name: 'Stranger'
};

var error = ova(person,  {
	name: { _rules: { type: 'string', disallow: 'Stranger' } }
});

console.log(error);

Output: