# fastify-formbody ![CI](https://github.com/fastify/fastify-formbody/workflows/CI/badge.svg) [![NPM version](https://img.shields.io/npm/v/fastify-formbody.svg?style=flat)](https://www.npmjs.com/package/fastify-formbody) [![NPM downloads](https://img.shields.io/npm/dm/fastify-formbody.svg?style=flat)](https://www.npmjs.com/package/fastify-formbody) [![JavaScript Style Guide](https://img.shields.io/badge/code_style-standard-brightgreen.svg)](https://standardjs.com) [![codecov](https://codecov.io/gh/fastify/fastify-formbody/branch/master/graph/badge.svg)](https://codecov.io/gh/fastify/fastify-formbody) [![Known Vulnerabilities](https://snyk.io/test/github/fastify/fastify-formbody/badge.svg)](https://snyk.io/test/github/fastify/fastify-formbody) A simple plugin for [Fastify][fastify] that adds a content type parser for the content type `application/x-www-form-urlencoded`. [fastify]: https://www.fastify.io/ This branch targets Fastify v3. Please refer to [this branch](https://github.com/fastify/fastify-formbody/tree/3.x) and related versions for Fastify `^2.0.0` compatibility. ## Example Given the following code: ```js const fastify = require('fastify')() fastify.register(require('fastify-formbody')) fastify.post('/', (req, reply) => { reply.send(req.body) }) fastify.listen(8000, (err) => { if (err) throw err }) ``` And a `POST` body of: ```html foo=foo&bar=bar&answer=42 ``` The sent reply would be the object: ```js { foo: 'foo', bar: 'bar', answer: 42 } ``` ## Options The plugin accepts an options object with the following properties: + `bodyLimit`: The maximum amount of bytes to process before returning an error. If the limit is exceeded, a `500` error will be returned immediately. When set to `undefined` the limit will be set to whatever is configured on the parent Fastify instance. The default value is whatever is configured in [fastify](https://github.com/fastify/fastify/blob/master/docs/Factory.md#bodylimit) (`1048576` by default). + `parser`: The default parser used is the querystring.parse built-in. You can change this default by passing a parser function e.g. `fastify.register(require('fastify-formbody'), { parser: str => myParser(str) })` ## Upgrading from 4.x Previously, the external [qs lib](https://github.com/ljharb/qs) was used that did things like parse nested objects. For example: - ***Input:*** `foo[one]=foo&foo[two]=bar` - ***Parsed:*** `{ foo: { one: 'foo', two: 'bar' } }` The way this is handled now using the built-in querystring.parse: - ***Input:*** `foo[one]=foo&foo[two]=bar` - ***Parsed:*** `{ 'foo[one]': 'foo', 'foo[two]': 'bar' }` If you need nested parsing, you must configure it manually by installing the qs lib (`npm i qs`), and then configure an optional parser: ```js const fastify = require('fastify')() const qs = require('qs') fastify.register(require('fastify-formbody'), { parser: str => qs.parse(str) }) ``` ## License Licensed under [MIT](./LICENSE)