MongoDb cluster connection with React Native App - node.js

Question

I am very new to React Native. As part of my learning i was trying to connect a Mongodb Atlas cluster to my RN App. But I am very confused in developing the code for a post request to the Mongodb cluster. I was following a tutorial to develop a sample taxi booking app. It would be great if someone helps me to understand the code.
So my server code is as follows:
var express = require("express");
var path = require("path");
var bodyParser = require("body-parser");
var index = require("./routes/index");
var bookings = require("./routes/bookings");
var app = express();
var port = 3000;
app.listen(port,function(){
console.log("Server running on port",port);
})
//views
app.set("views", path.join(__dirname,"views"));
app.set("view engine","ejs");
app.engine("html", require("ejs").renderFile);
//Body Parser MW
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended:true}))
//Routes
app.use("/",index);
app.use("/api",bookings);
Then i have a bookings.js file as follows:
var express = require("express");
var router = express.Router();
var MongoClient = require("mongodb").MongoClient ;
var uri = "mongodb+srv://TheCarAdmin:admin0000#thecarcluster-3hqxd.mongodb.net/test?&w=majority";
router.post("/bookings",function(req,res,next){
var bookings =req.body.data;
if(!bookings.username){
res.status(400);
res.json({
error:"Bad data"
});
}
else {
MongoClient.connect(uri)
.then(client=>{
const db = client.db("TheCar");
const coll = db.collection("bookings");
coll.save(bookings,function(err,savedBooking){
if(err){
res.send(err);
}
res.json(savedBooking);
});
})
.catch(err=>console.log(err));
}
});
module.exports = router;
In my App code i have a function that handles logging the booking request to the MongoDB collection as follows:
import update from "react-addons-update";
import constants from "./actionConstants";
import Geolocation from "react-native-geolocation-service";
import {Dimensions} from "react-native";
import RNGooglePlaces from "react-native-google-places";
import request from "../../../util/request";
import calculateFare from "../../../util/fareCalaculator";
export function bookCar(){
return(dispatch,store)=>{
const payload = {
data:{
username:"eman",
pickUp:{
address :store().home.selectedAddress.selectedPickUp.address,
name : store().home.selectedAddress.selectedPickUp.name,
latitude: store().home.selectedAddress.selectedPickUp.location.latitude,
longitude: store().home.selectedAddress.selectedPickUp.location.longitude
},
dropOff:{
address :store().home.selectedAddress.selectedDropOff.address,
name : store().home.selectedAddress.selectedDropOff.name,
latitude: store().home.selectedAddress.selectedDropOff.location.latitude,
longitude: store().home.selectedAddress.selectedDropOff.location.longitude
},
fare: store().home.fare,
status:"pending"
}
}
request.post("http://172.20.10.2:3000/api")
.send(payload)
.finish((err,res)=>{
dispatch({
type : BOOK_CAR,
payload : res.body
});
console.log(err.message);
console.log(res.status);
});
};
}
So as shown above the Request is imported from the following file:
const request = require("superagent");
const defaultAjaxTimeout = 30000;
//const cookie = require("cookie");
request.Request.prototype.finish = function (callback) {
// this replaces superagent's .end() function to include our custom error handling (see above)
this.end((err,res)=>{
callback(err,res);
});
};
var requestWrapper = function(method) {
// this is here so that we can append the .timeout call to all of our ajax requests with the default value.
return function(url) {
return request[method](url)
.type("form")
.timeout(defaultAjaxTimeout);
};
};
export default {
get: requestWrapper("get"),
put: requestWrapper("put"),
post: requestWrapper("post"),
del: requestWrapper("del"),
};
When i was debugging I realised that its not getting redirected to the booking.js code to process the POST request and hence throwing error. Could anyone help me to understand how this gets redirected to bookings.js or correct me if the written code is wrong.
Thanks in advance!!!!!