Sengi-express NPM

Sengi Express

This package is part of the Sengi family.

An ExpressJS RESTful host for a Sengi-based document service.

This modules provides a createSengiExpress function that returns an Express Request handler that you can mount using app.use.

Installation

npm install sengi-express

Usage

import { MemDocStore } from 'sengi-docstore-mem'
import { createSengiExpress } from 'sengi-express'
import { v4 } from 'uuid'

const docTypes = [] // import implementations of DocType interface
const clients = [] // import implementations of Client interface

const memDocStore = new MemDocStore({ docs, generateDocVersionFunc: v4 })
const sengiExpress = createSengiExpress({
  docStore: memDocStore,
  docTypes,
  clients
})

const app = express()
app.use(bodyParser.json())
app.use('/', sengiExpress)

Constructor

To instantiate a sengi-express server you pass the constructor parameters defined for a sengi-engine plus the following additional properties:

additionalComponentsCount - The number of additional components to be expected between the / and /docTypeName component parts of the request url. This can be used for capturing additional url parameters (e.g. tenant id).
getDocStoreOptions - A function that returns an object that will be provided to the DocStore and included in DocStore callbacks.
getRequestOptions - A functino that returns an object that will be provided to the Sengi Engine and included in Sengi Engine callbacks.
getUuid - A function that generates a unique identifier, used for ensuring uniqueness of operations and patches. If not supplied then the uuid/v4 package is used by default.

The getDocStoreOptions and getRequestOptions callbacks will be passed a SengiExpressCallbackProps object. This contains the following properties:

headers - An object where each key name is a header name and each value is the corresponding header value sent with a request.
path - The path of the request.
matchedResourceType - The type of resource that was matched from the RestResourceType enum.
method - The method of the request, e.g. GET, POST, etc
urlParams - The parameters pulled from the url as a consequence of matching the resource type. Possible keys are adc, docTypePluralName, id and operationName.

Routes

A SengiExpress mounted at the / path would make a number of different routes accessible. If you want to divide your doc types into collections, then mount multiple handlers at different points, e.g. /cars and /bikes.

The examples below assume that Sengi is mounted at /sengi.