wallter

Wallter is an express and restify middleware validator that uses validator.js and has the ability to build validation schema straight from your mongoose model. It can dig up to the deepest defined array and/or array of objects and validate the data.

It is highly influenced by ctavan/express-validator and relying from chriso/validator.js, wallter does almost the same goal as validator. The edge is, it supports auto validation for arrays, nested arrays, and/or nested arrays of objects without using customValidator workaround.

Installation

npm install --save wallter

Usage

Sample Mongoose Model

require('./model')()
const restify = require('restify')
const mongoose = require('mongoose')
 
const halter = require('wallter').halter
const Builder = require('wallter').builder
 
const server = restify.createServer({ name: 'myapp', version: '1.0.0'});
 
const builder = new Builder({
  uuid: true,
  model: mongoose.model('TestModel'),
  templates: {
    unique: `Expecting unique value in '%1$s' field. (Model: %2$s, Field: %3$s)`
  }
})
 
server.use(restify.plugins.acceptParser(server.acceptable))
server.use(restify.plugins.queryParser())
server.use(restify.plugins.bodyParser())
 
server.use(halter({
  customValidators: {
    // sample custom validator, supporting mongoose 'unique')
    unique: (value, modelName, field) => {
      return new Promise((resolve, reject) => {
        return setTimeout(() => {
          resolve()
        }, 500)
      })
    }
  }
}))
 
server.post('/test', function (req, res, next) {
  let validationSchema = builder
    .location('body')
    .exclude(['arr.*.foo'])
    .addRule('email', 'unique', ['modelName', 'email']) // custom validator above
    .build()
 
  req.halt(validationSchema).then(result => {
    if (result.length) {
      res.send(400, result)
    } else {
      res.send(200)
    }
    
    return next()
  })
})
 
server.listen(8080, function () {
  console.log('%s listening at %s', server.name, server.url);
})

Validator

All validator specified in validator.js v9.2.0 are attached and its validator name will be used as the rule name in validation schema.

Builder

Options

Option	Description
uuid	Force to add validation isUUID() to fields _id and ref. Default: false
uuidVersion	Version to use once uuid is enabled. Default: 5
model	Mongoose object model to parse to generate validation schema.
templates	Error message templates object for your custom validator (see section below for Error Messages).

Validation Schema Generator/Builder (Mongoose specific)

The messy problems arrives if you have multiple REST resource and you need to write validation schema in each resource, or clever way is to reuse some of them if possible. But still it is messy. So why not use a validation schema generator from a defined mongoose model?

const Builder = require('wallter').builder
 
const builder = new Builder({
  uuid: true,
  model: mongoose.model('TestModel'),
  templates: {
    unique: `Expecting unique value in '%1$s' field. (Model: %2$s, Field: %3$s)`
  }
})
 
let schema = builder.build()
console.log(schema)

Sample Mongoose Schema
Sample Validation Schema - Output

Validation Schema Manipulator

See basic tests for an in depth usage and samples.

Methods	Description
addRule(path, rule, options)	Add validation rule to existing validation item or create a new validation item params: - path {string} - path to property to validate - rule {string} - validation name, it can be from validator.js or your custom validator - options {array} - ordered params to pass to validator, successive array items can be used to print values in error message
addRules([[path, rule, options]])	Multilple addRule() param: rules {array} - array of addRule() params
build()	Generate schema.
cherryPick(options)	Set multiple location and select the defined items only (aka: pickByLoc()). param: options {object} - {location: [fieldPath, ...], ...} e.g. {query: ['_id'], body: ['foo.bar', 'arr.*.foo.bar']}
dropRule(path, rules)	Remove validation rule from schema item params: - path {string} - path to property to validate - rules {string|string[]} - validation rule names to remove
exclude(paths)	Remove specific field from pre generated schema (if mongoose model were attached) param: paths {(string|string[])} - path to property to validate
fresh()	Produce an empty schema (ignoring mongoose model)
select(paths)	Get specific field from pre generated schema (if mongoose model were attached) param: paths {(string|string[])} - path to property to validate`
setLocation(loc)	Adds specific location (in each property to validate, or to the selected ones) on where to pull the data. currently supported locations are 'params', 'query', 'body' param: loc {string} - possible values are: params|query|body
setLocations(options)	Multiple location setting. param: options {object} - {location: [fieldPath, ...], ...} e.g. {query: ['_id'], body: ['foo.bar', 'arr.*.foo.bar']}
setOptional(path)	Set field to validate as optional param: path {string} - path to property to validate
setRequired(path)	Set field to validate as required param: path {string} - path to property to validate
unstrict(arrPath)	Setting array of objects as optional even if object property inside is required param: arrPath {(string|string[])} - path to property

Error Messages

By default, error messages to some validators are templated (see it here), but you can specify your own message by passing your error message template to our builder options.

It uses sprintf.js (vsprintf specifically) as an underlying mechanism to pass values to error messages/templates.

let options = {
  uuid: true,
  model: mongoose.model('BasicModel'),
  templates: {
    unique: `Expecting unique value in '%1$s' field.`,
    yourValidator: `Your message here, you can pass param values using sprintf.js syntax`
  }
}

Printing param values

In addRule() the 3rd array param options handles all values that you want to attach to your error message, but there is a numbering scheme. By default, I attached the path as the first item of the options array, the 2nd and succeeding will be the options to be passed to validator options if needed. Check sprintf.js or these tests for an in depth usage.

License

MIT License