node-validator is a library of string validation, filtering and sanitization methods.
To install node-validator, use npm:
$ npm install validator
To use the library in the browser, include validator-min.js
Example
var check = require('validator').check,
sanitize = require('validator').sanitize
//Validate
check('test@email.com').len(6, 64).isEmail(); //Methods are chainable
check('abc').isInt(); //Throws 'Invalid integer'
check('abc', 'Please enter a number').isInt(); //Throws 'Please enter a number'
check('abcdefghijklmnopzrtsuvqxyz').is(/^[a-z]+$/);
//Sanitize / Filter
var int = sanitize('0123').toInt(); //123
var bool = sanitize('true').toBoolean(); //true
var str = sanitize(' \s\t\r hello \n').trim(); //'hello'
var str = sanitize('aaaaaaaaab').ltrim('a'); //'b'
var str = sanitize(large_input_str).xss();
var str = sanitize('<a>').entityDecode(); //'<a>'
Web development
Often it's more desirable to check or automatically sanitize parameters by name (rather than the actual string). See this gist for instructions on binding the library to the request
prototype.
Example http://localhost:8080/?zip=12345&foo=1&textarea=large_string
get('/', function (req, res) {
req.onValidationError(function (msg) {
//Redirect the user with error 'msg'
});
//Validate user input
req.check('zip', 'Please enter a valid ZIP code').len(4,5).isInt();
req.check('email', 'Please enter a valid email').len(6,64).isEmail();
req.checkHeader('referer').contains('localhost');
//Sanitize user input
req.sanitize('textarea').xss();
req.sanitize('foo').toBoolean();
//etc.
});
List of validation methods
is() //Alias for regex()
not() //Alias for notRegex()
isEmail()
isUrl() //Accepts http, https, ftp
isIP()
isAlpha()
isAlphanumeric()
isNumeric()
isInt() //isNumeric accepts zero padded numbers, e.g. '001', isInt doesn't
isLowercase()
isUppercase()
isDecimal()
isFloat() //Alias for isDecimal
notNull()
isNull()
notEmpty() //i.e. not just whitespace
equals(equals)
contains(str)
notContains(str)
regex(pattern, modifiers) //Usage: regex(/[a-z]/i) or regex('[a-z]','i')
notRegex(pattern, modifiers)
len(min, max) //max is optional
List of sanitization / filter methods
trim(chars) //Trim optional `chars`, default is to trim whitespace (\r\n\t\s)
ltrim(chars)
rtrim(chars)
ifNull(replace)
toFloat()
toInt()
toBoolean() //True unless str = '0', 'false', or str.length == 0
toBooleanStrict() //False unless str = '1' or 'true'
entityDecode() //Decode HTML entities
entityEncode()
xss() //Remove common XSS attack vectors from text (default)
xss(true) //Remove common XSS attack vectors from images
Extending the library
When adding to the Validator prototype, use this.str
to access the string and this.error(this.msg || default_msg)
when the string is invalid
var Validator = require('validator').Validator;
Validator.prototype.contains = function(str) {
if (!~this.str.indexOf(str)) {
this.error(this.msg || this.str + ' does not contain ' + str);
}
return this; //Allow method chaining
}
When adding to the Filter (sanitize) prototype, use this.str
to access the string and this.modify(new_str)
to update it
var Filter = require('filter').Filter;
Filter.prototype.removeNumbers = function() {
this.modify(this.str.replace(/[0-9]+/g, ''));
return this.str;
}
Error handling
By default, the validation methods throw an exception when a check fails
try {
check('abc').notNull().isInt()
} catch (e) {
console.log(e); //Invalid integer
}
To set a custom error message, set the second param of check()
try {
check('abc', 'Please enter a valid integer').notNull().isInt()
} catch (e) {
console.log(e); //Please enter a valid integer
}
To attach a custom error handler, set the error
method of the validator instance
var Validator = require('validator').Validator;
var v = new Validator();
v.error = function(msg) {
console.log('Fail');
}
v.check('abc').isInt(); //'Fail'
Contributors
PING - Fixed entity encoding
LICENSE
(MIT License)
Copyright (c) 2010 Chris O'Hara cohara87@gmail.com
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.