README.md
# API Problem
RFC 7807 - Problem Details for HTTP APIs
[![license][license-img]][license-url]
[![release][release-img]][release-url]
[![super linter][super-linter-img]][super-linter-url]
[![test][test-img]][test-url]
[![semantic][semantic-img]][semantic-url]
> [RFC 7807 - Problem Details for HTTP APIs][]
## Install
``` bash
npm install api-problem
```
## API
### Constructor: `Problem(status[, title][, type][, members])`
| name | type | required | default | description | referece |
|---------------|----------|----------|--------------------|----------------------------------------------------------------------------------------|------------------|
| **`status`** | `String` | `✔` | `N/A` | The HTTP status code generated by the origin server for this occurrence of the problem | [Section 3.1][] |
| **`title`** | `String` | `✖` | HTTP status phrase | A short, human-readable summary of the problem type | [Section 3.1][] |
| **`type`** | `String` | `✖` | `about:blank` | A URI reference that identifies the problem type | [Section 3.1][] |
| **`details`** | `Object` | `✖` | `N/A` | additional details to attach to object | [Section 3.1][1] |
``` js
import Problem from 'api-problem'
// HTTP defaults
new Problem(404)
//=> { status: '404', title: 'Not Found', type: 'https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/404' }
// override defaults
new Problem(404, 'Oops! Page Not Found')
//=> { status: '404', title: 'Oops! Page Not Found', type: 'https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/404' }
// custom values
new Problem(403, 'You do not have enough credit', 'https://example.com/probs/out-of-credit')
//=> { status: '403', title: 'You do not have enough credit', type: 'https://example.com/probs/out-of-credit' }
// additional details
new Problem(403, 'You do not have enough credit', 'https://example.com/probs/out-of-credit', {
detail: 'Your current balance is 30, but that costs 50.',
instance: '/account/12345/msgs/abc',
balance: 30,
accounts: ['/account/12345', '/account/67890']
})
//=> { status: '403', title: 'You do not have enough credit', type: 'https://example.com/probs/out-of-credit', detail: 'Your current balance is 30, but that costs 50.', instance: '/account/12345/msgs/abc', balance: 30, accounts: ['/account/12345', '/account/67890'] }
// HTTP defaults + Details
new Problem(403, {
detail: 'Account suspended',
instance: '/account/12345',
date: '2016-01-15T06:47:01.175Z',
account_id: '12345'
})
//=> { status: '403', title: 'Forbidden', type: 'https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/403', detail: 'Account suspended', instance: '/account/12345', account_id: 12345, 'date: 2016-01-15T06:47:01.175Z' }
```
### Method : `<object>` `toObject()`
returns an object containing all the properties including: *(status, title, type, members)*
``` js
const prob = new Problem(403, 'You do not have enough credit', 'https://example.com/probs/out-of-credit', { user_id: 'x123' })
prob.toObject() //=> { status: 403, title: 'You do not have enough credit', type: 'https://example.com/probs/out-of-credit', user_id: 'x123' }
```
### Method : `<string>` `toString()`
returns a simplified, human-readable string representation
``` js
const prob = new Problem(403, 'You do not have enough credit', 'https://example.com/probs/out-of-credit')
prob.toString() //=> [403] You do not have enough credit ('https://example.com/probs/out-of-credit')
```
### Method : `<void>` `send(response)`
uses [`response.writeHead`][] and [`response.end`][] to send an appropriate error response message with the `Content-Type` response header to [`application/problem+json`][]
``` js
import http from 'http'
import Problem from 'api-problem'
let response = new http.ServerResponse()
Problem.send(response)
```
### Express Middleware
A standard connect middleware is provided. The middleware intercepts Problem objects thrown as exceptions and serializes them appropriately in the HTTP response while setting the `Content-Type` response header to [`application/problem+json`][]
``` js
import express from 'express'
import Problem from 'api-problem'
import Middleware from 'api-problem/lib/middleware'
const app = express()
app.get('/', (req, res) => {
throw new Problem(403)
})
app.use(Middleware)
```
[RFC 7807 - Problem Details for HTTP APIs]: https://tools.ietf.org/html/rfc7807
[Section 3.1]: https://tools.ietf.org/html/rfc7807#section-3.1
[1]: https://tools.ietf.org/html/rfc7807#section-3.2
[`response.writeHead`]: https://nodejs.org/docs/latest/api/http.html#http_response_writehead_statuscode_statusmessage_headers
[`response.end`]: https://nodejs.org/docs/latest/api/http.html#http_response_end_data_encoding_callback
[`application/problem+json`]: https://tools.ietf.org/html/rfc7807#section-3
----
> Author: [Ahmad Nassri](https://www.ahmadnassri.com/) •
> Twitter: [@AhmadNassri](https://twitter.com/AhmadNassri)
[license-url]: LICENSE
[license-img]: https://badgen.net/github/license/ahmadnassri/node-api-problem
[release-url]: https://github.com/ahmadnassri/node-api-problem/releases
[release-img]: https://badgen.net/github/release/ahmadnassri/node-api-problem
[super-linter-url]: https://github.com/ahmadnassri/node-api-problem/actions?query=workflow%3Asuper-linter
[super-linter-img]: https://github.com/ahmadnassri/node-api-problem/workflows/super-linter/badge.svg
[test-url]: https://github.com/ahmadnassri/node-api-problem/actions?query=workflow%3Atest
[test-img]: https://github.com/ahmadnassri/node-api-problem/workflows/test/badge.svg
[semantic-url]: https://github.com/ahmadnassri/node-api-problem/actions?query=workflow%3Arelease
[semantic-img]: https://badgen.net/badge/📦/semantically%20released/blue