@ojizero/portal NPM

portal

HTTP API clients ... simplified.

Motivation

Inspired when developing an internal API client in my company Yamsafer :heart:, and by the design of the Cloudflare NodeJS client :heart:.

This library aims to simplify the creation of HTTP API clients by providing a declarative abstraction of HTTP requests.

Instead of worrying about how to consume some HTTP API, we should focus on the buisness logic behind this API call, so instead of worrying about whether the HTTP request library uses promises, or callbacks, or how the response object is formated, you simply declare what you want, and move on with your life.

So instead of having the focus be centered around how you make the request like the following,

import request from 'request' // or who knows what you wanna use ¯\_(ツ)_/¯

function myApiWrapper (arg1, arg2) {
  return new Promise((resolve, reject) => {
    request(
      `https://some.api/some/url/${arg1}/some-resource/${arg2}`,
      /*other options who knows,*/
      (error, response, data) => {
        if (error) reject(error)

        resolve(response) // or data ¯\_(ツ)_/¯
      }
    )
  })
}

/// TOO MUCH BOILERPLATE !!

The above boilerplate where you worry about whether you're using request or request-promise or whatnot, and you worry about how to resolve your response and what it looks like, get completely abstracted and unified into,

import portal from '@ojizero/portal'

const portalBase = portal({ baseUrl: 'https://some.api' })

const myApiWrapper = portalBase.route({ path: '/some/url/:arg1/some-resource/:arg2' })

/// Woosh done :D

And you gain the consistent response structure (placed inside a promise). This can be extended even further into building entire clients for you APIs!

It also adds support for standardized validation for request arguments, query strings, and payload (provided using Joi :heart:)

Installation

With NPM

npm i -S @ojizero/portal

Or if you're into Yarn

yarn add @ojizero/portal

Usage

Aimed to be used as a building block for API client libraries

/// In your library or definition file
import portal from '@ojizero/portal'

const client = portal({ baseUrl: 'some.base.url' }) // Initial configuration can be passed here

// Get method without path variables
export const someGetMethod = client.route({ path: '/some/path' })
// Get method with path variables
export const someGetMethodWithParam = client.route({ path: '/some/path/:withInnerVariable' })
// Post method with path variables
export const somePostMethodWithParam = client.route({ path: '/some/path/:withInnerVariable', method: 'POST' })

/// NOTE: ideally this wouldn't be a module level instance but this is to simplify this example 😬

/* ******************* */

/// In your application
import * as YourAPIClient from 'your-client-module'

const someGetMethodPromise = YourAPIClient.someGetMethod() // GET http://some.base.url/some/path
const someGetMethodWithParamPromise = YourAPIClient.someGetMethodWithParam(5) // GET http://some.base.url/some/path/5
const somePostMethodWithParamPromise = YourAPIClient.someGetMethodWithParam(5, { payload: { some: 'payload' } }) // POST http://some.base.url/some/path/5 { some: 'payload' }

Examples can be found in the examples folder

API Documentation

(default export) createPortalClient(config)

Used to create a portal base client. Returns a portal object

config

All config options are required unless otherwise stated.

baseUrl

Type: string (required).

The base URL used by the client, all related URIs are prepended by it.

headers

Type: OutgoingHttpHeaders

The default headers to be attached to all requests.

authentication

Type: Authentication

Authentication

type

Type: AuthenticationTypes (required)

Valid AuthenticationTypes are:

None = 'none'
- No authentication required. (same as not providing the authentication option)
BasicAuth = 'basic',
- Use username and password to generate a token.
- Token is added to the Authorization header prepended with basic.
BearerAuth = 'bearer',
- Use authToken as is.
- Token is added to the Authorization header prepended with bearer.

username

Type: string

Required if using BasicAuth type.

password

Type: string

Required if using BasicAuth type.

authToken

Type: string

Required if using BearerAuth type.

retries

Type: number

Number of retries to execute on failures, default is 0.

timeout

Type: number

Request timeout in seconds, default is 30

onError

Type: 'reject' | 'resolve'

TODO: I think it's not working currently 🤔

If set to resolve error won't throw, instead will return a normal response, default is reject.

Portal Object

The returns object has three attributes,

route

A function (representing a MethodFactory), used to generate client routes. It takes for an input a MethodSpec and returns a function representing the API call.

MethodSpec

An object with the following attributes

path (required) string

The URL path for the route, it should be a relateive path given the baseUrl defined when initiating the portal client.

method (optional) string

The method for the HTTP call, defaults to GET.

params (optional) ValdiationSpec

An optional validation specification for the path arguments in of the route.

body (optional) ValdiationSpec

An optional validation specification for the payload arguments of the route.

queryString (optional) ValdiationSpec

An optional validation specification for the query string arguments in of the route.

contentType (optional) string

The Content-Type header value of the request, defaults to application/json.

accept (optional) string

The Accept header value of the request, defaults to application/json.

headers (optional) OutgoingHttpHeaders

Additional headers to always be added to requests to the given route, defaults to {}.

Usage example

/* --- snip --- */

const getRoute = portalObject.route({ path: '/some/base/path' })
await getRoute() // GET /some/base/path
await getRoute({ queryString: { a: 10 } }) // GET /some/base/path?a=10

/* --- snip --- */

const postRoute = portalObject.route({ path: '/some/base/path', method: 'POST' })
await postRoute({ payload: { some: 'payload' } }) // POST /some/base/path { some: 'payload' }

/* --- snip --- */

RouteFunction

Type: (...args: any[]): Promise<Response>

A function that takes any number of arguments and performs the HTTP request.

The only special argument is the last one, which can be an object hodling any request options that can be used by the underlying client, as well as the payload (under the key payload) and query string (under the key queryString) objects if needed.

Example calls would be

getMethod(arg1, arg2, /*...,*/ argn)
getMethod(arg1, arg2, /*...,*/ argn, { queryString: { q: 'hello' } })
postMethod(arg1, arg2, /*...,*/ argn, { payload: { q: 'hello' } })

All calls to a RouteFunction produce a promise that resolves to an oject of Response type.

Response

An object with the following attributes,

status, which is an object holding the HTTP status both as a message and a code.
body, any response body returns from the HTTP request
headers, HTTP headers returned for the response
_rawResponse, the raw underlying HTTP response object (from the underlying client library)

export interface Response {
  status: {
    code?: number,
    word?: string,
  },
  body: any,
  headers: IncomingHttpHeaders,
  [Symbol.for('portal:symbols:raw-response')]: RawResponse,
}

resource

A function (representing a ResourceFactory), and can be used to generate client resources. A resource is a basic CRUD API for a given route, providing a default set of APIs for list, get, edit, add, and delete, those APIs correspond to the following HTTP calls,

list -> GET /some-uri
get -> GET /some-uri/:id
edit -> PUT /some-uri/:id { some payload to update the ID with }
add (aliased as set) POST /some-uri { some payload to create a new reource with }
del (aliased as delete) DELETE /some-uri/:id

It takes a ResourceConfig object as input and returns a ResourceFactory function. When calling the ResourceFactory, the result is an object with the list of CRUD operations (and any additional ones defined in the resource config) as function defined on it.

The result from using the resource factory, is an object with the enabled default resource method, and any other extra ones as its keys, and each of those keys poiting to the RouteFunction used to execute the API call.

ResourceConfig

An object with the following attributes,

baseRoute (required) string

The base API route to generate the CRUD around.

enabledRoutes (optional) Array<string>

The list of routes to enable, by default all basic CRUD APIs are enabled.

extraMethods (optional) { [k:string]: MethodSpec }

A JSON with string keys mapping to corresponding MethodSpec. Each key will be added an added method defined by it's corresponding spec. Defaults to {}.

Usage example

/* --- snip --- */

const apiResource = portalObject.resource({ baseRoute: '/some/base/path' })
/**
 * apiResource has the following methods on it
 *   list, get, edit, add, set, del, delete
 * corresponding the default set of APIs in an HTTP resource
 */

await apiResource.list() // GET /some/base/path
await apiResource.get(someId) // GET /some/base/path/:someId
// ... etc

/* --- snip --- */

Each method defined on the resource object follows the type RouteFunction.

_client

The underlying client instance used by the two previous factories. This is exposed only for transparncy but is not intended to be used ideally by anyone external.

Usage of the portal object

RouteFunction

Status

This is still a work in progress :D any help is appreciated

TODO

Finish documentations
- Why?
- More on external API
Support non JSON payload
Get onError: resolve to work
Support simplified form for validation
Finalize behvaiour of genreator method functions
- What to do with their arguments (ambiguity of options/payload/querystring in args)
- Document RouteFunction behvaiour
Browser support through Ky ?