Basic rest api with express framework for node

install

$ git clone https://github.com/star-ter-js/starter-express-api.git
$ cd starter-express-api
$ npm install
$ npm run serve

Server runs at this address http://localhost:8888/

getting started: geocoder example

In app/services directory put code like this in "esriGeocode.service.js" file:

// services/esriGeocode.service.js
const fetch = require('node-fetch');

async function geocode(address) {
  address = encodeURIComponent(address.trim());
  const url = `https://geocode.arcgis.com/arcgis/rest/services/World/GeocodeServer/FindAddressCandidates?F=pjson&SingleLine=${address}`;
  
  try {
    let resp = await fetch(url).then(resp => resp.json());

    //do stuff with "resp"

    return resp;
  } catch (err) {
    throw new Error(err);
  }
} // geocode

module.exports = geocode;

that you can use in routers definition file in app/routers directory

// routers/esriGeocode.router.js
const express = require('express');
const {addRoute} = require('.');
const geocode = require('../services/esriGeocode.service.js');

let router = express.Router();
addRoute({
  router,
  path: '/:address',
  method: 'GET',
  transformRequest: req => req.params.address,
  getResponce: geocode,
  transformResponce: resp => resp.candidates.map(candidate => `${candidate.address} [${candidate.extent.xmin}, ${candidate.extent.ymin}, ${candidate.extent.xmax}, ${candidate.extent.ymax}]`),
});

module.exports = router;

and finnally in config/routes.js

// config/routes.js
const routes = {
  .....
  '/geocode': 'esriGeocode.router',
  ....
}; // routes
module.exports = routes;

Now in the working directory you can type

npm  run serve

in the browser you can type "http://localhost:8888/geocode/empire+state+building+ny" and you can get the response:

{
  "status": "OK",
  "results": [
    "Empire State Building [-73.99066999999997, 40.74343000000004, -73.98066999999998, 40.753430000000044]"
  ],
  "items": 1
}

set expresss ROUTER

addRoute function input

router: express.Router instance;
method: method router ('GET' 'POST', etc)
url: string endpoint api;
handler function if handler returns handler
transformRequest: [function,] functions that transform request object and returns variable for input in getResults. Default is req => ({ params: req.params, query: req.query });
getResponse: function that take variable returned by transformRequest and returns a Promise object with response of the api
transformResponse: function that transform the response returned by getResults. Default is null.
wrapResponce boolean
mime: mime type string for the responce. Default is 'application/json'.
endResponse: function. Default is null for standard response.

File structure

services directory

In services/ directory put .js file to define service

routers directory

In routers/ directory put .js file to define router instance express.Router()

config directory

In config/ directory the file

routes.js define the routes;
server.js define the server variable like port.

License

MIT