express-validator
An express.js middleware for
node-validator.
This is basically a copy of a gist by
node-validator author chriso.
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.assert('getparam', 'Invalid getparam').isInt();
req.assert('urlparam', 'Invalid urlparam').isAlpha();
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
};
}
}));
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>"
}
}
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 extend the Validator
and Filter
objects to add custom validation
and sanitization method.
Custom validation which always fails. Useful for debugging or for
adding messages manually when doing complex validation:
var expressValidator = require('express-validator');
expressValidator.Validator.prototype.fail = function() {
this.error(this.msg);
return this;
};
Custom sanitization which lower-cases the string:
expressValidator.Filter.prototype.toLowerCase = function(){
this.modify(this.str.toLowerCase());
return this.str;
};
Changelog
v0.4.1
v0.4.0
- Added
req.checkBody()
(@zero21xxx). - Upgraded validator dependency to 1.1.3
v0.3.0
req.validationErrors()
now returns null
instead of false
if there are no errors.
v0.2.4
- Support for regex routes (@Cecchi)
v0.2.3
- Fix checkHeader() (@pimguilherme)
v0.2.2
- Add dot-notation for nested input (@sharonjl)
- Add validate() alias for check()
v0.2.1
- Fix chaining validators (@rapee)
v0.2.0
- Added
validationErrors()
method (by @orfaust) - Added support for nested form fields (by @orfaust)
- Added test cases
v0.1.3
v0.1.2
- Expose Filter and Validator instances to allow adding custom methods
v0.1.1
- Use req.param() method to get parameter values instead of accessing
req.params directly.
- Remove req.mixinParams() method.
v0.1.0
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