STEP 2: Initialize the project

Let’s start from the beginning. Open the terminal and create a project folder

>mkdir api-access-test
>cd api-access-test
>npm init

This creates a vanilla node project.

Now let’s install a few libraries:

npm install --save axios custom-env express jwt-simple moment querystring

Next, fire up your favorite editor. I will be using Visual Studio Code.

STEP 3: Build the Controller class

In the project’s root folder, create a controller class. This will be the main class for managing connections to iFormBuilder

iform-api-controller.js

Starts with setting up all the required libraries

const jwt = require('jwt-simple');
const moment = require('moment');
const axios = require('axios');
const qs = require('querystring');
require('custom-env').env();

Next set up all the required environment variables

const CLIENT_SECRET = process.env.IFORM_CLIENT_SECRET;
const CLIENT_KEY = process.env.IFORM_CLIENT_KEY;
const SERVERNAME = process.env.IFORM_SERVERNAME;
const DOMAIN = process.env.IFORM_DOMAIN;
const PROFILE_ID = process.env.IFORM_PROFILE_ID;
const PAGE_ID=process.env.IFORM_PAGE_ID;const OAUTH_URL = `https://${SERVERNAME}.${DOMAIN}/exzact/api/oauth/token`
const BASE_URL = `https://${SERVERNAME}.${DOMAIN}/exzact/api/v60/profiles/${PROFILE_ID}/pages/${PAGE_ID}/records`

This example assumes you are trying to pull data from iFormBuilder. If you are accessing other API, your BASE_URL will be different.

Notice we are trying to load environment variables.

Let’s set up the env file for development

Create the file: [.env] in the project’s root folder

IFORM_CLIENT_SECRET = "XXX"
IFORM_CLIENT_KEY = "XXX"
IFORM_SERVERNAME = "[servername]"
IFORM_DOMAIN = "iformbuilder.com"
IFORM_PROFILE_ID = 999
IFORM_PAGE_ID=999

Going back to the controller class

We will start by defining the class name

class IFormAPIController{constructor(){
    this.accessToken=null;
    this.tokenExpiration=Number.MAX_VALUE;
}

The next two functions uses OAuth to authenticate to iFormBuilder using JWT:

async _getAccessToken() {
    const expires = moment().add(5, 'minutes').unix();
    const timestamp = moment().unix();    let token = jwt.encode({
        iss: CLIENT_KEY,
        aud: OAUTH_URL,
        exp: expires,
        iat: timestamp
    }, CLIENT_SECRET);    const params = {
        grant_type:'urn:ietf:params:oauth:grant-type:jwt-bearer',
        assertion:token
    }    const config = {
        headers: {
            'Content-Type': 'application/x-www-form-urlencoded'
        }
    }    try {
        let t = await axios.post(OAUTH_URL, qs.stringify(params), config)
        this.accessToken = t.data.access_token;
        this.tokenExpiration = moment().add(t.data.expires_in,'seconds').unix();        console.log("Token = "+this.accessToken);
        return (this.accessToken)
    } catch (err){
        if (err.response) {
            console.log(err.response.data)
            return(err.response.data)
        } else if (err.request) {
            console.log(err.request)
            return(err.request)
        } else {
            console.log(err)
            return(err)
        }
    }
  }async getAccessToken(){
    if (!this.accessToken || moment().add(1, 'minutes').unix() > this.tokenExpiration) {
    await this._getAccessToken();
    }
    return this.accessToken;
}

The _getAccessToken function creates a JWT token in order to obtain an access token. The getAccessToken function checks if there is an existing access token and to see if the token has expired. If so, it will call _getAccessToken to obtain a new token, otherwise, it will just return the existing token.

From here on, you can just call getAccessToken() to authenticate.

Next, let’s write a get request to receive data from iFormBuilder.

async getData(field1){    await this.getAccessToken();
    let url = `${BASE_URL}?fields=field1${field1?'(="'+field1+'")':''},field2`    const config = {
        headers: {
            'Authorization': 'Bearer ' + this.accessToken
         }
    }    try {
        let res = await axios.get(url,config)
        console.log(res.data)
        return (res.data)
    } catch (err){
        if (err.response) {
            return(err.response.data)
        } else if (err.request) {
            return(err.request)
        } else {
            return(err)
        }
    }
}}//Close classmodule.exports = IFormAPIController;

This function illustrates how to send a get request to the iFormBuilder API. It pulls 2 fields: field1 and field2, with field1 being a parameter one can search from. See iFormBuilder API documentation for other API url.

POST, PUT, and DELETE request takes similar forms.

Now that we have the controller done, we will create an Express router.

The goal of the router is to route HTTP traffic to the controller and return data back to the client.

Create the file [iform-router.js]:

const IFormAPIController = require('./iform-api-controller');
const express = require('express');class IFormAPIRouter{    constructor(){
        this.init();
        this.controller = new IFormAPIController();
    }    init(){
        this.router = express.Router();
        this.router.get('/', async (req, res) => {
            console.log("GET")
            console.log(req.query);
            let field1 = req.query['field1']
            
            try {
                let data = await this.controller.getData(field1);
                res.send(data);            } catch (err){
                console.log("ERR In ROUTER")
                console.log(err.message)
                res.send('ERROR:'+err.message)            }        })     }}module.exports = IFormAPIRouter;

This router routes any get quests to the ‘/’ path to the controller. If you want to handle other HTTP requests, you will create additional routes.

var express = require('express')
var bodyParser = require('body-parser')
var path = require('path');
var IFormAPIRouter = require('./iform-api-router');
require('custom-env').env()// declare a new express app
var app = express()
app.use(bodyParser.json())const apiRouter = new IFormAPIRouter();
app.use('/api', apiRouter.router)app.listen(3000, function() {
    console.log("App started")
});

To start the server,

>node index.js

Now you should be able to point your browser, or your frontend, to HTTP://localhost:3000/api?field1=value

Here is the complete controller file. Enjoy.