<\/p>\n\n\n\n
var mymath = require(\".\/mymodule\")\n\nconsole.log(mymath.add(5,6));\nconsole.log(mymath.sub(5,6));\nconsole.log(mymath.mul(5,6));\nconsole.log(mymath.div(5,6));\nconsole.log(mymath.mod(5,6));\n\ncobj = new mymath.MyCircle(5);\ncobj.area();<\/code><\/pre>\n\n\n\nmymodule.js<\/h1>\n\n\n\nexports.add = (x, y) => x + y;\nexports.sub = (x, y) => x \u2013 y;\nexports.mul = (x, y) => x * y;\nexports.div = (x, y) => x \/ y;\nexports.mod = (x, y) => x % y;\n\nexports.MyCircle = class {\n\nconstructor(r) {\n this.radius = r;\n console.log(\"Hello I am My Circle Constructor...\");\n}\n\narea() {\n let area = Math.PI * this.radius * this.radius;\n console.log(`Area: ${area.toFixed(2)}`);\n}\n}<\/code><\/pre>\n\n\n\n<\/p>\n\n\n\n
NODE http MODULE<\/h1>\n\n\n\nindex.js<\/h1>\n\n\n\nvar http = require(\u201chttp\u201d)\n\nhttp.createServer((req, res) => {\n\/\/ res.writeHead(\u2018Content-Type\u2019, \u2018text\/plain\u2019);\n\/\/ res.writeHead(\u2018Content-Type\u2019, \u2018application\/json\u2019);\nres.writeHead(200, {\u2018Content-Type\u2019 : \u2018text\/html\u2019});\nres.write(\"this is line 1\u2026.\");\n\nconsole.log(req.url);\n\nif(req.url == \"\/\") {\n res.write(\"Home req hit<\/br>\")\n} else \n\nif(req.url == \"\/teacher\") {\n res.write(\"Teacher req hit<\/br>\")\n} else \n\nif(req.url == \"\/student\") {\n res.write(\"Student req hit<\/br>\")\n} else \n\n{\n res.end(\"Page Not Found....\");\n}\n\nres.end(\"hello world....\");\n}).listen(8989, () => {\nconsole.log(\"listening at port 8989\u2026\")\n});<\/code><\/pre>\n\n\n\n<\/p>\n\n\n\n
EXPRESS ROUTING<\/h1>\n\n\n\nindex.js<\/h1>\n\n\n\nvar express = require(\"express\");\nvar app = express();\n\napp.get(\"\/\", (req, res) => {\n res.send(\"Home Page\");\n});\n\napp.get(\"\/student\", (req, res) => {\n data = { result: \"Student GET Request\" };\n res.send(data);\n});\n\napp.post(\"\/student\", (req, res) => {\n data = { result: \"Student post Request\" };\n res.send(data);\n});\n\napp.put(\"\/student\", (req, res) => {\n data = { result: \"Student put Request\" };\n res.send(data);\n});\n\napp.delete(\"\/student\", (req, res) => {\n data = { result: \"Student delete Request\" };\n res.send(data);\n});\n\napp\n .route(\"\/teacher\")\n .get((req, res) => {\n data = { result: \"Teacher get Request\" };\n res.send(data);\n })\n .post((req, res) => {\n data = { result: \"Teacher post Request\" };\n res.send(data);\n })\n .put((req, res) => {\n data = { result: \"Teacher put Request\" };\n res.send(data);\n })\n .delete((req, res) => {\n data = { result: \"Teacher delete Request\" };\n res.send(data);\n });\n\n\napp.listen(8989, () => {\n console.log(\"Listening at port 8989\");\n});\n<\/code><\/pre>\n\n\n\nRUN COMMAND<\/h1>\n\n\n\n#if file is index.js then you can simply run using . instead of filename\nnode .\nnode app.js\n\n#install nodemon\nnpm i nodemon\nOR\nnpm i -g nodemon\n\nnodemon .\nnodemon app.js\n\nOR\n \n.\/node_modules\/nodemon\/bin\/nodemon.js .\n.\/node_modules\/nodemon\/bin\/nodemon.js app.js<\/code><\/pre>\n\n\n\nEXPRESS MODULAR ROUTING<\/h1>\n\n\n\nindex.js<\/h1>\n\n\n\nvar express = require(\"express\");\nvar app = express();\nvar home = require(\".\/home\");\nvar student = require(\".\/student\");\nvar teacher = require(\".\/teacher\");\n\napp.use(\"\/\", home);\napp.use(\"\/student\", student);\napp.use(\"\/teacher\", teacher);\n\napp.use(function (req, res, next) {\n res.status(404);\n res.send(\"404: File Not Found\");\n});\n\napp.listen(8989, () => {\n console.log(\"Listening at port 8989\");\n});\n<\/code><\/pre>\n\n\n\nstudent.js<\/h1>\n\n\n\nconst express = require(\"express\");\nconst router = express.Router();\n\nrouter\n .route(\"\/\")\n .get((req, res) => {\n res.send(\"student listing\");\n })\n\n .post((req, res) => {\n res.send(\"student post\");\n })\n\n .put((req, res) => {\n res.send(\"student put\");\n })\n\n .delete((req, res) => {\n res.send(\"student delete\");\n });\n\nmodule.exports = router;\n<\/code><\/pre>\n\n\n\nteacher.js<\/h1>\n\n\n\nconst express = require(\"express\");\nconst router = express.Router();\nrouter\n .route(\"\/\")\n .get((req, res) => {\n res.send(\"teachers listing\");\n })\n .post((req, res) => {\n res.send(\"teachers post\");\n })\n .put((req, res) => {\n res.send(\"teachers put\");\n })\n .delete((req, res) => {\n res.send(\"teachers delete\");\n });\n\nmodule.exports = router;\n<\/code><\/pre>\n\n\n\nEXPRESS READ DATA <\/h1>\n\n\n\nindex.js<\/h2>\n\n\n\nconst express = require(\"express\");\nconst app = express();\napp.use(express.json());\n\napp\n .route(\"\/\")\n .get((req, res) => {\n data = req.query;\n res.send(data);\n })\n .post((req, res) => {\n data = req.body;\n res.send(data);\n })\n .put((req, res) => {\n data = req.body;\n res.send(data);\n });\n\n\napp.listen(8989, () => {\n console.log(\"Listening at port 8989\");\n});\n<\/code><\/pre>\n\n\n\nAssignment: WA Web Service to read number from user and return square and cube of that number. Return data in JSON format.<\/p>\n\n\n\n
Database Connection<\/h1>\n\n\n\ndbconn.js<\/h2>\n\n\n\nconst express = require(\"express\");\nconst mysql = require(\"mysql2\");\nconst cors = require(\"cors\");\n\nconst app = express();\napp.use(cors());\napp.use(express.json());\n\nconst db = mysql.createConnection({\n host: \"localhost\",\n user: \"root\",\n password: \"your_mysql_password\",\n database: \"todo_app\"\n});\n\ndb.connect();\n\n\/\/ GET all todos\napp.get(\"\/todos\", (req, res) => {\n db.query(\"SELECT * FROM todos\", (err, rows) => {\n res.json(rows);\n });\n});\n\n\/\/ GET todo by id\napp.get(\"\/todos\/:id\", (req, res) => {\n const sql = `SELECT * FROM todos WHERE id=${req.params.id}`;\n db.query(sql, (err, rows) => {\n res.json(rows[0]);\n });\n});\n\n\/\/ CREATE todo\napp.post(\"\/todos\", (req, res) => {\n const sql = `INSERT INTO todos (title) VALUES ('${req.body.title}')`;\n db.query(sql, (err, result) => {\n res.json({ id: result.insertId, title: req.body.title, completed: false });\n });\n});\n\n\/\/ UPDATE todo\napp.put(\"\/todos\/:id\", (req, res) => {\n const sql = `UPDATE todos SET title='${req.body.title}', completed=${req.body.completed} WHERE id=${req.params.id}`;\n db.query(sql, () => {\n res.json({ message: \"Updated\" });\n });\n});\n\n\/\/ DELETE todo\napp.delete(\"\/todos\/:id\", (req, res) => {\n const sql = `DELETE FROM todos WHERE id=${req.params.id}`;\n db.query(sql, () => {\n res.json({ message: \"Deleted\" });\n });\n});\n\napp.listen(3000, () => {\n console.log(\"Server running on http:\/\/localhost:3000\");\n});\n\n<\/code><\/pre>\n\n\n\nFetch Api<\/h2>\n\n\n\n<table border=1>\n\t<thead>\n\t\t<th>Id<\/th>\n\t\t<th>Name<\/th>\n\t\t<th>Email<\/th>\n\t\t<th>Aavatar<\/th>\n\t<\/thead>\n\t<tbody id=\"records<\/strong>\">\n\t\t<tr>\n\t\t\t<td>sample <\/td>\n\t\t\t<td>sample<\/td>\n\t\t\t<td>sample<\/td>\n\t\t\t<td>sample<\/td>\n\t\t<\/tr>\n\t<\/tbody>\n\n<\/table>\n<img id=\"image\" \/>\n<script>\n\turl = \"https:\/\/reqres.in\/api\/users?page=1\";<\/strong>\n\n\tfetch(url)\n\t.then(res => res.json())\n\t.then(result => {\n\t\tconsole.table(result.data);\n\t\tconsole.log(result.data[0]['avatar'])\n\t\tdocument.getElementById(\"image\").src = result.data[0]['avatar'];\n\t\trecords = result.data;\n\t\toutput = '';\n\t\tfor(i = 0;i<records.length; i++){\n\t\t\toutput += `<tr>`\n\t\t\toutput += `<td>${records[i]['id']} <\/td>`\n\t\t\toutput += `<td>${records[i]['first_name']} ${records[i]['last_name']}<\/td>`\n\t\t\toutput += `<td>${records[i]['email']}<\/td>`\n\t\t\toutput += `<td><img id=\"image\" src=\"${records[i]['avatar']}\" \/><\/td>`\n\t\t\toutput += `<\/tr>`\n\t\t\tconsole.log(records[i]['id'])\n\t\t}\n\tdocument.getElementById(\"records\").innerHTML = output;\n\t\n\t})\n\t\n<\/script><\/code><\/pre>\n\n\n\nExpress File Upload<\/h2>\n\n\n\n\/\/get directory name\nconsole.log(`Project Path: ${__dirname}`);\n\nconst express = require(\"express\");\nconst fileUpload = require(\"express-fileupload\");\nconst app = express();\n\n\/\/options \/ middleware\napp.use(fileUpload());\n\napp.post(\"\/file_upload\", (req, res) => {\n\t\n\tconsole.log(req.body);\n\tconsole.log(req.files);\n\t\n\tlet file_to_upload = req.files.file_to_upload;\n\t\n\t\/\/file_to_upload.mv(path,callbackfun);\n\tconst upload_path = __dirname + '\/uploads\/' + file_to_upload.name;\n\t\/\/file_to_upload.mv(upload_path);\n\t\n\tfile_to_upload.mv(upload_path, (err) => {\n\t\tif(err) {\n\t\t\tres.status(500)\n\t\t\tres.send(err);\n\t\t}\n\t\t\n\t\tres.status(200)\n\t\tres.send(\"File Upload successfully...\")\n\t})\n\t\n});\n\napp.listen(8989, () => {\n\tconsole.log(\"Listening at port 8989\");\n})<\/code><\/pre>\n\n\n\njson webtoken<\/strong><\/p>\n\n\n\nconst express = require(\"express\");\nconst jwt = require(\"jsonwebtoken\");\nconst cors = require(\"cors\");\n\nconst app = express();\napp.use(express.json());\napp.use(cors());\n\n\/\/ Secret key (keep in env var in production)\nconst SECRET_KEY = \"shhhhh\";\n\n\/\/ Dummy credentials\nconst USERNAME = \"admin\";\nconst PASSWORD = \"@dmin\";\n\n\/\/ ---------------------------\n\/\/ \ud83d\udd10 JWT Auth Middleware\n\/\/ ---------------------------\nfunction verifyToken(req, res, next) {\n const authHeader = req.headers.authorization;\n\n if (!authHeader || !authHeader.startsWith(\"Bearer \")) {\n return res.status(401).json({ message: \"No token provided\" });\n }\n\n const token = authHeader.split(\" \")[1];\n\n jwt.verify(token, SECRET_KEY, (err, decoded) => {\n if (err) {\n return res.status(403).json({ message: \"Invalid or expired token\" });\n }\n\n req.user = decoded; \/\/ attach decoded data to request\n next();\n });\n}\n\n\/\/ ---------------------------\n\/\/ \ud83e\udde9 Routes\n\/\/ ---------------------------\n\n\/\/ Login route - issues token\napp.post(\"\/login\", (req, res) => {\n const { username, password } = req.body;\n\n if (username !== USERNAME || password !== PASSWORD) {\n return res.status(401).json({ message: \"Invalid credentials\" });\n }\n\n const token = jwt.sign({ username, role: \"manager\" }, SECRET_KEY, {\n expiresIn: \"1h\",\n });\n\n res.json({ token });\n});\n\n\/\/ Protected routes\napp.get(\"\/dashboard\", verifyToken, (req, res) => {\n res.json({ message: `Welcome ${req.user.username} to the dashboard` });\n});\n\napp.get(\"\/employees\", verifyToken, (req, res) => {\n res.json({ message: \"Employee page data\", user: req.user });\n});\n\n\/\/ ---------------------------\n\/\/ \ud83c\udfc3 Start Server\n\/\/ ---------------------------\napp.listen(8080, () => {\n console.log(\"\u2705 Server listening at http:\/\/localhost:8080\");\n});\n\n\n<\/code><\/pre>\n\n\n\natlas.js<\/h2>\n\n\n\nconst conn_str = \"mongodb+srv:\/\/<username>:<password><\/strong>@clusterurl_obtained_from_mongodbatlas\/<databasename><\/strong>?retryWrites=true&w=majority\";\n\/\/please replace username password and database name \nconst mongoose = require(\"mongoose\");\n\nmongoose.connect(conn_str)\n.then(() => console.log(\"Connected successfully...\"))\n.catch( (error) => console.log(error) );\n\n\nconst express = require(\"express\");\nconst app = express();\napp.use(express.json());\n\nconst empSchema = new mongoose.Schema({});\nconst emp = new mongoose.model(\"emps\", empSchema);\n\n\nvar cors = require('cors')\napp.use(cors())\n\n\napp.get(\"\/employees\", async (req, res) => {\n \/\/ var data = [{name: \"hari\", salary: 25000}, {name: \"sameer\", salary: 23000}]\n let data = await emp.find();\n res.send(data)\n})\n\napp.listen(8989, () => {\n\tconsole.log(\"listening 8989...\");\n});\n<\/code><\/pre>\n\n\n\nindex.js<\/h2>\n\n\n\n<link href=\"https:\/\/cdn.jsdelivr.net\/npm\/bootstrap@5.3.2\/dist\/css\/bootstrap.min.css\" rel=\"stylesheet\" integrity=\"sha384-T3c6CoIi6uLrA9TneNEoa7RxnatzjcDSCmG1MXxSR1GAsXEV\/Dwwykc2MPK8M2HN\" crossorigin=\"anonymous\">\n<script src=\"https:\/\/cdn.jsdelivr.net\/npm\/bootstrap@5.3.2\/dist\/js\/bootstrap.bundle.min.js\" integrity=\"sha384-C6RzsynM9kWDrMNeT87bh95OGNyZPhcTNXj1NW7RuBCsyN\/o0jlpcV8Qyq46cDfL\" crossorigin=\"anonymous\"><\/script>\n\n<table class=\"table table-striped\">\n <thead>\n <tr>\n <th>Name<\/th>\n <th>City<\/th>\n <th>Phone No.<\/th>\n <th>Salary<\/th>\n <th>Action<\/th>\n <\/tr>\n <\/thead>\n <tbody id=\"records\"><\/tbody>\n<\/table>\n\n\n<script>\n\nurl = \"http:\/\/localhost:8989\/employees\"\n\nfetch(url)\n.then(res => res.json())\n.then(res => {\n console.log(res)\n console.table(res)\n\n output = ''\n\n for(let i = 0; i < res.length; i++) {\n\n output += `<tr>\n <td>${res[i]['name']}<\/td>\n <td>${res[i]['address']}<\/td>\n <td>${res[i]['contact_number']}<\/td>\n <td>${res[i]['salary']}<\/td>\n <td><button class=\"btn btn-danger\">Delete<\/button><\/td>\n <\/tr>`\n }\n\n document.getElementById(\"records\").innerHTML = output\n})\n\n<\/script><\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"NODE CUSTOM MODULE index.js mymodule.js NODE http MODULE index.js EXPRESS ROUTING index.js RUN COMMAND EXPRESS MODULAR ROUTING index.js student.js teacher.js EXPRESS READ DATA index.js Assignment: WA Web Service to read number from user and return square and cube of that number. Return data in JSON format. Database Connection dbconn.js Fetch Api Express File Upload json […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[18],"tags":[],"_links":{"self":[{"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/posts\/1003"}],"collection":[{"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/comments?post=1003"}],"version-history":[{"count":33,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/posts\/1003\/revisions"}],"predecessor-version":[{"id":2942,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/posts\/1003\/revisions\/2942"}],"wp:attachment":[{"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/media?parent=1003"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/categories?post=1003"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/codeinsightacademy.com\/blog\/wp-json\/wp\/v2\/tags?post=1003"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}