validation-middleware

validation-middleware
====================
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[![Build Status][travis-badge]](https://travis-ci.org/Alejinho/validation-middleware)

Flexible asynchronous validation middleware to sanitize and validate parameters
at the same time.
Based on validator.

Installing
----------
``sh
npm install validation-middleware
`

Use
----------

Which parameters does it receive? options, source = 'body', context = 'request'.

First param, options, this field is an object with the items you want to validate, e.g:

`javascript
{
_id: 'isMongoId',
date: ['required', 'isDate'], // By default the parameters are not required
website: {
required: true,
isUrl: {
params: {
protocols: ['https'],
require_host: true
}
}
}
}
`

The second param, source, it will tell middleware function where to find
values to validate, by default it uses body key, but here you can find
the same rules of the next item.

The third param, context, it will specify an object useful if you want
to set your custom function and then have multiple options; those string values are allowed:
1. context will return an object {request: ..., response: ..}
2. request or response, ___by default we use___ request
3. Any key in the request object.

Validators
----------

Those are the available attributes for a validation stage.
`javascript
{
// Dot notation is allowed
'field.name': {
:{
// Everything here is optional

// It will be passes as parameters to the validation
// function, if it needs more than 1 parameter
// you should set an array
params: ,

// There's some custom messages, but you can specify it.
message: "Custom message, {{campo}} reference to the filed name",
^
----------
as: "It replace 'campo' value",
sanitize: {
// Sanitize stages that will be called if validation passes
// Same rules of validation are allowed here
}
}
}
}

`

It's flexible because there's different ways to make a validation middleware, you can
define custom functions too:

`javascript
{
email: ['required', 'isEmail'],
name: 'required',
'user.name': {
required: true, // First validation stage
custom: { // Second validation stage
function(value, pattern, next){
return value.match(pattern)
},
params: /.*/ig
},
... // Other stages
}
}
`

This is a list with the allowed validation function names, required validation stage is different,
if it's set to false and the value from the source is empty the next stages are skipped.


Some functions have associated sanitizers functions by default:
1. isBoolean
2. isDate
3. isInt
4. isFloat
5. isMongoId
6. There's other sanitize function that could be assigned

If you want to avoid this behavior you should specify it, otherwise next middleware functions
will get updated values:

`javascript
{
'product._id': {
required: true,
isMongoId: {
sanitize: false
}
}
}
`

Error case
----------
You can set your own error constructor, then an instance of this will be passed
to the next express middleware

`javascript
function ValidationError(message) {
Error.call(this)
this.message = message
}

Object.setPrototypeOf(ValidationError.prototype, Error.prototype);

require('validation-middleware').setHttpError({
constructor: ValidationError
});

middleware = validator({
email: ['required', 'isEmail']
});

app.get('/', middleware, function(request, response, err) {
...
})

app.use(function(request, response, next, error){
error.should.be.instanceOf(ValidationError);
error.should.be.instanceOf(Error);
error.message.should.match(/The email must be a valid email address\./);
})

`


Example
-------

`javascript
let middleware = validator({
'user.uuid': {
required: false,
custom: {
function(value, options, next){
setTimeout(function () {
const maxLimit = options.maxLimit
next(value < maxLimit ? new Error('Range error') : '')
}, 1)
},
params: {
maxLimit: 10
},
required: false
}
},
_id: 'isMongoId',
email: {
required: true,
isEmail: {
sanitize: {
normalizeEmail: {}
}
},
},
});

// request.body = {
// user: {
// uuid: '9'
// },
// _id: '51b14c2de8e185801f000006',
// email: 'EXAMPLE@ACME.COM',
// }
app.get('/', middleware, function(request, response, next){
// request.body = {
// _id: ObjectId('51b14c2de8e185801f000006'),
// email: 'example@acme.com'
// }
//
});

`

TODO

1. Add support for more languages.
+ en_US should have better error messages.
+ See validator and add more error messages for
other functions.
2. Support for custom params error.
3. process.nextTick` is called every 3 times, it should be customizable.

[npm-badge]: https://img.shields.io/npm/v/validation-middleware.svg
[npm-d-badge]: https://img.shields.io/npm/dt/validation-middleware.svg
[travis-badge]: https://img.shields.io/travis/Alejinho/validation-middleware.svg
[sanitizer-list]: https://www.npmjs.com/package/validator#sanitizers
[validation-list]: https://www.npmjs.com/package/validator#validators
[validator]: https://www.npmjs.com/package/validator