Router.express() -> What is the proper way for expressing router.use? - node.js

Question

For router.use, it does not work like this anymore:
router.use("/api", apiRoutes);
Instead an error is thrown:
throw new typeerror('router.use() requires a middleware function but got a ' + gettype(fn))
How do I re-purpose that expression so that it works? I have not found any examples that were useful so far. Here is some of my sample code:
routes/index.js (this does not work)
const path = require("path");
const router = require("express").Router();
const apiRoutes = require("./api");
// API Routes
router.use("/api", apiRoutes);**// this throws an error**
router.use(function(req, res) {
res.sendFile(path.join(__dirname, "../client/build/index.html"));
});
module.exports = router;
Here is an example of my attempt to re-purpose but I do not think it's correct:
var path = require("path");
var router = require("express").Router();
var apiRoutes = require("./api");
//API Routes
//authRouter.use(require('./authenticate').basic(usersdb))
//router.use("./api", apiRoutes);
console.log("Hitting API routes...")
router.use("./api", function(req, res, next) { **//re-purpsose attempt here**
res.send(apiRoutes)
console.log("API Routes:", apiRoutes)
next()
});
console.log("API Routes hit")
// //If no API routes are hit, send the React app
// router.use(function(req, res) {
// res.sendFile(path.join(__dirname, "../client/public/index.html"));
// });
module.exports = router
This is the overall error I'm getting (404 returned):
GET /api/website_1_function_call/scrape 404 4.004 ms - 173
I know that this may be due to something else indirectly but I really am not sure about the router.use part.
I know for sure that the routes are not being hit properly and would like to fix.
Any advice would be appreciated. Thank you in advance.
Here is more code:
server.js
require("dotenv").config();
var express = require("express");
var cors = require('cors');
var bodyParser = require('body-parser');
var logger = require("morgan");
//const mongoose = require("mongoose");
var db = require("./models")
var routes = require("./routes");
var app = express();
var PORT = process.env.PORT || 3001;
var path = require('path');
//Define middleware here
app.use(express.urlencoded({ extended: true }));
app.use(express.json());
app.use(bodyParser.json());
//Serve up static assets (usually on heroku)
if (process.env.NODE_ENV === 'production') {
app.use(express.static("client/build"));
}
app.use(cors());
app.use(logger("dev"));
//Add routes, both API and view
app.use(routes);
//replaced with below:
//app.use(app.router);
//routes.initialize(app);
// //Connect to the Mongo DB
// mongoose.connect(process.env.MONGODB_URI || "mongodb://localhost/kaibru");
var syncOptions = { force: false };
// If running a test, set syncOptions.force to true
// clearing the `testdb`
if (process.env.NODE_ENV === "test") {
syncOptions.force = true;
};
// Starting the server, syncing our models ------------------------------------/
db.sequelize.sync(syncOptions).then(function() {
app.listen(PORT, function() {
console.log(
"==> 🌎 Listening on port %s. Visit http://localhost:%s/ in your browser.",
PORT,
PORT
);
});
});
// //Start the API server
// app.listen(PORT, function() {
// console.log(`🌎 ==> API Server now listening on PORT ${PORT}!`);
// });
routes/index.js
var path = require("path");
var router = require("express").Router();
var apiRoutes = require("./api");
//API Routes
//authRouter.use(require('./authenticate').basic(usersdb))
//router.use("/api", apiRoutes);
console.log("Hitting API routes...")
router.use("/api", function(req, res, next) { // this is my re-purpose
attempt
apiRoutes
console.log("API Routes:", apiRoutes)
// next()
}); // this is my r-purpose attempt
console.log("API Routes hit")
// //If no API routes are hit, send the React app
// router.use(function(req, res) {
// res.sendFile(path.join(__dirname, "../client/public/index.html"));
// });
module.exports = router
routes/api/index.js
var router = require("express").Router();
require("./website_1");
var website_1Routes = require("./website_1_function_call");
//const userRoutes = require("./user");
//Website_1 routes
//http://localhost:3000/api/website_1_function_call/scrape
//authRouter.use(require('./authenticate').basic(usersdb))
//router.use("/website_1_function_call", website_1Routes);
//experimental use
router.use("/website_1_function_call", function(req, res, next) { // this is my re-purpose attempt
website_1Routes
console.log("website_1Routes:", website_1Routes)
// next()
}); //this is my re-purpose attempt
//router.use("/user", userRoutes);
module.exports = router
routes/api/website_1_function_call.js
require("./website_1");
require("./website_1_db");
require("./website_1_router");
//Call scrape functions from website_1 file
mainscrape();
//specificScrape() //let's leave this one dormant for now
//Now for saving to database
saveToDatabase();
//Now for the routes
routing();
I think my re-purpose attempt worked ( I removed next() since there are no defined routes right after). It seems to be processing. However, now my response hangs and this happens:
GET /api/website_1_function_call/scrape - - ms - -
This prints in the browser console:
GET http://localhost:3000/api/website_1_function_call/scrape
net::ERR_EMPTY_RESPONSE
0.chunk.js:871 Uncaught (in promise) Error: Network Error
at createError (0.chunk.js:871)
at XMLHttpRequest.handleError (0.chunk.js:366)
So now I think my scraper code and my code to update the database does not work.
Scrape function code:
//var express = require("express");
var router = require("express").Router();
require("../../controllers/website_1controller");
//requiring this website's models
var Items_1 = require("../../models/website_1");
//require("./website_1_db");
//require("./website_1_router");
// Our scraping tools
// Axios is a promised-based http library, similar to jQuery's Ajax method
// It works on the client and on the server
var axios = require("axios");
var cheerio = require("cheerio");
mainscrape = function() {
//Now to configure the routes
router.get("/scrape", function(req, res) {
//instead of simple res.render, user router.get
console.log("scraping started...");
//Grab the html body with axios
axios.get("url placeholder").then(function(response) {
//Load to cheerio and save to $ selector
console.log("Scraping all greenheartshop mainpage...");
var $ = cheerio.load(response.data);
var output = [];
var promises = [];
//Now we need to grab the title reference for each article
$("article").each(function(i, element) {
//save empty result object
var result = {};
//thumbnail
result.thumbnail = $(this)
//.children("article.product-grid-item.product-block").html()
.children("figure.product-item-thumbnail")
.children("a")
.attr("href")
//console.log("result thumbnail")
//console.log(result)
console.log(result.thumbnail)
var result = {}
//details
result.detail= $(this)
//.children("product-item-mask").html()
.children("div.product-item-details")
// .children("div.product-item-brand")
// .children("h5.product-item-title")
// .children("a")
// .children("div.product-item-price")
//.children("product-price-line")
//.children("price-value")
.text()
//result.detail = result.detail.trim();
//console.log("result detail")
//console.log(result)
console.log(result.detail)
//Capture the scraped data and save to database
console.log("Capturing Scrape")
if(result.detail !== '') {
var promise = Items_1
.saveToDatabase(result, result, {upsert:true, new:true})
console.log("saveToDatabase");
promises.push(promise);
}
Promise.all(promises).then((data) => {
res.json(data);
});
//saveToDatabase();
// if (result.thumbnail !== {} && result.detail !== "") {
// var promise = Items_1
// // .items_1_create({
// // resultThumbnail: result.thumbnail,
// // resultDetails: result.detail
// // })
// promises.push(promise)
// // .then(dbModel => output.push(dbModel));
// Promise.all(promises).then((data) => {
// res.json(data)
// })
// }
});
});
//Now to CREATE the results using controller file
// console.log("creating items in the database now...")
// router.post('/scrape', website_1Controller.items_1_create);
//Now to display the results
// console.log("Items now being displayed...")
// router.get('/scrape/display', website_1Controller.items_1_list)
});
}
module.exports = router;
module.exports = mainscrape;
module.exports = specificScrape;
Code to update the database:
require("../../controllers/website_1controller");
require("./website_1");
var Items_1 = require( "../../models");
//After scraping the main page, the following function is to save to the
database
saveToDatabase = function() {
//prepare the data
var result = {}
var dataToStore = Items_1.items_1_create
console.log(dataToStore)
//console.log(items_1_create)
//insert data to the database
// dataToStore.save().// We will not sue this part for now
// then(() => {
// console.log("Data successfully saved");
// }).catch(err => {
// console.log("Error: ", err);
// });
}
module.exports = saveToDatabase;
Code for final routing (after scrape is complete)
var website_1Controller = require("../../controllers/website_1controller");
var router = require("express").Router();
routing = function() {
//Now to CREATE the results using controller file
console.log("creating items in the database now...")
//router.route("/browse")
router.post('/browse', website_1Controller.items_1_create);
router.get('/browse', website_1Controller.items_1_list);
//Now to display the results
console.log("Items now being displayed...")
//router.route("/browse:search")
router.get('/:search', website_1Controller.items_1_specific);
};
require("./website_1");
module.exports = routing;
module.exports = router;
models
'use strict';
// Dependencies
// =============================================================
// Sequelize (capital) references the standard library
//var Sequelize = require("sequelize");
// sequelize (lowercase) references our connection to the DB.
//var sequelize = require("../config/connection.js");
// Creates a "Items_1" model that matches up with DB
module.exports = function(sequelize, DataTypes) {
var Items_1 = sequelize.define("Items_1", {
// the routeName gets saved as a string
detail: DataTypes.STRING,
// the name of the character (a string)
thumbnail: DataTypes.BLOB,
// the character's role (a string)
//role: Sequelize.STRING,
// the character's age (a string)
//age: Sequelize.INTEGER,
// and the character's force points (an int)
//forcePoints: Sequelize.INTEGER
}, {
// disable the modification of tablenames; By default, sequelize will
automatically
// transform all passed model names (first parameter of define) into
plural.
// if you don't want that, set the following
freezeTableName: true
});
return Items_1;
//Syncs with DB
//Items_1.sync();
// Makes the Items_1 Model available for other files (will also create a table)
};
controller
// *********************************************************************************
// website_1controllers.js - this file offers a set of routes for displaying and saving data to the db
// *********************************************************************************
// Dependencies
// =============================================================
var db = require("../models");
//display results for mainpage scrape
exports.items_1_create = function(req, res) {
db.Items_1.findOneAndUpdate(req.body, req.body, {upsert: true, new:
true})
.then(dbModel => res.json(dbModel))
.catch(err => res.status(422).json(err))
console.log("findOneAndUpdate complete")
},
exports.items_1_list = function(req,res) {
db.Items_1.findAll({})
},
exports.items_1_specific = function(req,res) {
db.Items_1.findById(req.params.search)
},
function(err, results) {
if (err) { return next(err); } //Error in API usage.
if (results.result.thumbnail==={} && results.result.detail==="") {//No
Results.
var err = new Error('Results not found');
err.status = 404;
return next(err)
}
//Successful, so render
res.render("click_results", { title: 'Click Results', resultThumbnail:
result.thumbnail, resultDetails: result.detail });
}
So the new issue is that the response hangs. I think it's because the code to update the database does not work (using sequelize). Let me know if anything else is needed and thank you in advance.

Answer 1

Thanks for all of the input everyone. After reviewing I found out that the function itself does not have to be re-purposed as I initially thought... I didn't know that if, for example, you are using "router.use("/directoy", directory) and you are using it in succession to point to different directories, the final directory hit must have a defined route like router.get(). I modularized my code to the point where the final directory was just a list of functions (one of these functions had the router.get method). This did not work. When I point the file directly to the code containing the router.get method, my scraped data returns to the terminal. Just thought I'd share my findings at least because I didn't know this at all . Many thanks to #mehta-rohan and #Anand Undavia for the insights. I'm still trying to get the data to render to the page but that's a different problem altogether.