express-validator
An express.js middleware for
node-validator.
Installation
npm install express-validator
Usage
var util = require('util'),
express = require('express'),
expressValidator = require('express-validator'),
app = express.createServer();
app.use(express.bodyParser());
app.use(expressValidator([options]));
app.post('/:urlparam', function(req, res) {
req.checkBody('postparam', 'Invalid postparam').notEmpty().isInt();
req.checkParams('urlparam', 'Invalid urlparam').isAlpha();
req.checkQuery('getparam', 'Invalid getparam').isInt();
req.sanitize('postparam').toBoolean();
var errors = req.validationErrors();
if (errors) {
res.send('There have been validation errors: ' + util.inspect(errors), 400);
return;
}
res.json({
urlparam: req.param('urlparam'),
getparam: req.param('getparam'),
postparam: req.param('postparam')
});
});
app.listen(8888);
Which will result in:
$ curl -d 'postparam=1' http://localhost:8888/test?getparam=1
{"urlparam":"test","getparam":"1","postparam":true}
$ curl -d 'postparam=1' http://localhost:8888/t1est?getparam=1
There have been validation errors: [
{ param: 'urlparam', msg: 'Invalid urlparam', value: 't1est' } ]
$ curl -d 'postparam=1' http://localhost:8888/t1est?getparam=1ab
There have been validation errors: [
{ param: 'getparam', msg: 'Invalid getparam', value: '1ab' },
{ param: 'urlparam', msg: 'Invalid urlparam', value: 't1est' } ]
$ curl http://localhost:8888/test?getparam=1&postparam=1
There have been validation errors: [
{ param: 'postparam', msg: 'Invalid postparam', value: undefined} ]
Middleware Options
####errorFormatter
function(param,msg,value)
The errorFormatter
option can be used to specify a function that can be used to format the objects that populate the error array that is returned in req.validationErrors()
. It should return an Object
that has param
, msg
, and value
keys defined.
app.use(expressValidator({
errorFormatter: function(param, msg, value) {
var namespace = param.split('.')
, root = namespace.shift()
, formParam = root;
while(namespace.length) {
formParam += '[' + namespace.shift() + ']';
}
return {
param : formParam,
msg : msg,
value : value
};
}
}));
####customValidators
{ "validatorName": function(value, [additional arguments]), ... }
The customValidators
option can be used to add additional validation methods as needed. This option should be an Object
defining the validator names and associated validation functions.
Define your custom validators:
app.use(expressValidator({
customValidators: {
isArray: function(value) {
return Array.isArray(value);
},
gte: function(param, num) {
return param >= num;
}
}
}));
Use them with their validator name:
req.checkBody('users', 'Users must be an array').isArray();
req.checkQuery('time', 'Time must be an integer great than or equal to 5').isInt().gte(5)
Validation errors
You have two choices on how to get the validation errors:
req.assert('email', 'required').notEmpty();
req.assert('email', 'valid email required').isEmail();
req.assert('password', '6 to 20 characters required').len(6, 20);
var errors = req.validationErrors();
var mappedErrors = req.validationErrors(true);
errors:
[
{param: "email", msg: "required", value: "<received input>"},
{param: "email", msg: "valid email required", value: "<received input>"},
{param: "password", msg: "6 to 20 characters required", value: "<received input>"}
]
mappedErrors:
{
email: {
param: "email",
msg: "valid email required",
value: "<received input>"
},
password: {
param: "password",
msg: "6 to 20 characters required",
value: "<received input>"
}
}
Optional input
You can use the optional()
method to check an input only when the input exists.
req.checkBody('email').optional().isEmail();
Nested input data
Example:
<input name="user[fields][email]" />
Provide an array instead of a string:
req.assert(['user', 'fields', 'email'], 'valid email required').isEmail();
var errors = req.validationErrors();
console.log(errors);
Output:
[
{
param: "user_fields_email",
msg: "valid email required",
value: "<received input>"
}
]
Alternatively you can use dot-notation to specify nested fields to be checked:
req.assert(['user.fields.email'], 'valid email required').isEmail();
Regex routes
Express allows you to define regex routes like:
app.get(/\/test(\d+)/, function() {});
You can validate the extracted matches like this:
req.assert(0, 'Not a three-digit integer.').len(3, 3).isInt();
Extending
You can add your own validators using the customValidators
option. See Middleware Options for usage details.
Changelog
See CHANGELOG.md
Contributors
- Christoph Tavan dev@tavan.de - Wrap the gist in an npm package
- @orfaust - Add
validationErrors()
and nested field support - @zero21xxx - Added
checkBody
function
License
Copyright (c) 2010 Chris O'Hara cohara87@gmail.com, MIT License