strong-params

 

Rails-style implementation of strong parameters. It supports Express, Koa and also can be used as standalone. The middleware adds the parameters object to the Express request (or ctx.parameters for Koa context) which returns an object, built from query string, request body and route params data. The returned object has some useful methods allows for data requiring and filtering.

Notice

The implementation of strong parameters was previously forked from koa-strong-params but now has it's own implementation. Along with this change only, except and merge methods have been dropped from the API as they do not exist in Rails Strong Parameters API.

Installation

Install the npm package.

npm install strong-params --save

Attach the middleware.

Express

var express = require('express')
var params = require('strong-params')
app.use(params.expressMiddleware())

Koa

var koa = require('koa')
var params = require('strong-params')
var app = new koa()
app.use(params.koaMiddleware())

Usage

Get strong parameters

Express

app.use(function (req, res, next) {
  var params = req.parameters
})

Koa

app.use(function (ctx, next) {
  var params = ctx.parameters
})

Standalone

var Parameters = require('strong-params').Parameters
var params = Parameters({
  id: '13',
  name: 'Bob',
  age: '13',
  hobbies: ['skydiving', 'football', 'photographing'],
  address: {
    country: 'US',
    street: '261 West'
  },
  contacts: [
    {
      type: 'e-mail',
      value: '[e-mail]'
    }, {
      type: 'mobile',
      value: '[phone]'
    }
  ]
})

Methods

// All available params
params.all()
// -> { id: '13', name: 'Bob', age: '13', hobbies: ['skydiving', 'football', 'photographing'], address: { country: 'US', street: '261 West' }, contacts: [{ type: 'e-mail', value: '[e-mail]' }, { type: 'mobile', value: '[phone]' }] }
 
// Only selected params
params.permit('name', 'age').value()
// -> { name: 'Bob', age: '13' }
 
params.permit('id', 'name', {hobbies: []}).value()
// -> { id: '13', name: 'Bob', hobbies: ['skydiving', 'football', 'photographing'] }
 
params.permit('id', 'name', {contacts: []}).value()
// -> { id: '13', name: 'Bob', contacts: [] }
 
params.permit('id', 'name', {contacts: ['type', 'value']}).value()
// -> { id: '13', name: 'Bob', contacts: [{ type: 'e-mail', value: '[e-mail]' }, { type: 'mobile', value: '[phone]' }] }
 
// All params of a sub-object
params.require('address').all()
// -> { country: 'US', street: '261 West' }
 
// All params of a sub-object
params.require('contacts').permit('type', 'value').value()
// -> [{ type: 'e-mail', value: '[e-mail]' }, { type: 'mobile', value: '[phone]' }]

Errors

// ParameterMissingError
try {
  params.require('missingKey')
} catch(err) {
  err instanceof ParameterMissingError // -> true
  err instanceof Error // -> true
}

Look Rails Strong Parameters specification for more information.

Contributing

Please follow Contributing