{"id":109,"date":"2019-12-20T22:27:53","date_gmt":"2019-12-20T22:27:53","guid":{"rendered":"https:\/\/www.kindsonthegenius.com\/nodejs\/?p=109"},"modified":"2022-03-09T08:48:11","modified_gmt":"2022-03-09T08:48:11","slug":"rest-api","status":"publish","type":"post","link":"https:\/\/www.kindsonthegenius.com\/nodejs\/rest-api\/","title":{"rendered":"Node.js – Create a REST API"},"content":{"rendered":"

You can use Node.js to build REST APIs very easily.<\/p>\n

In this tutorial, we would build a REST API for managing user details. Our API would be able too<\/p>\n

 <\/p>\n

    \n
  1. Create the JSON LIbrary<\/a><\/li>\n
  2. Get list of users<\/a><\/li>\n
  3. Insert a user<\/a><\/li>\n
  4. Get a single user by Id<\/a><\/li>\n
  5. Delete a user by Id<\/a><\/li>\n<\/ol>\n

     <\/p>\n

    1. Create the JSON Library<\/strong><\/h5>\n

    As you know, if you are going to manipulate data, you need some database. In out case, we would just use data file in a directory.<\/p>\n

    The file containing list of users would be a json file named users.json.<\/p>\n

    The users file contain four fields: id, firstname, lastname and email.<\/p>\n

    The content of the user.json file is given below.
    \n<\/p>\n

    {\r\n  \"user1\"<\/span>: {\r\n    \"id\"<\/span>:1<\/span>,\r\n    \"firstname\"<\/span>:\"Munonye\"<\/span>,\r\n    \"lastname\"<\/span>:\"Kindson\"<\/span>,\r\n    \"email\"<\/span>:\"kany@gmail.com\"<\/span>\r\n  },\r\n\r\n  \"user2\"<\/span>:  {\r\n    \"id\"<\/span>:2<\/span>,\r\n    \"firstname\"<\/span>:\"Imolode\"<\/span>,\r\n    \"lastname\"<\/span>:\"Saffron\"<\/span>,\r\n    \"email\"<\/span>:\"saffron@gmail.com\"<\/span>\r\n  },\r\n\r\n  \"user3\"<\/span>:  {\r\n    \"id\"<\/span>:3<\/span>,\r\n    \"firstname\"<\/span>:\"Munonye\"<\/span>,\r\n    \"lastname\"<\/span>:\"Othniel\"<\/span>,\r\n    \"email\"<\/span>:\"othniel@gmail.com\"<\/span>\r\n  },\r\n\r\n  \"user4\"<\/span>: {\r\n    \"id\"<\/span>:4<\/span>,\r\n    \"firstname\"<\/span>:\"Yuba\"<\/span>,\r\n    \"lastname\"<\/span>:\"Oleander\"<\/span>,\r\n    \"email\"<\/span>:\"oleander@gmail.com\"<\/span>\r\n  }\r\n}\r\n<\/pre>\n
     <\/p>\n
    2. Return a List of Users<\/strong><\/h5>\n
    We would now create a REST API to return a list of users by reading the users.json file. We are going to use Express Framework<\/a>. You learnt this in the preceding section<\/a>.<\/p>\n
    So create\u00a0 a file named server.js and place it in the same directory with the users.json file. The content of the server.js file is shown below:<\/p>\n
     <\/p>\n
    \/\/REST API demo in Node.js<\/span>\r\nvar<\/span> express =<\/span> require('express'<\/span>); \/\/ requre the express framework<\/span>\r\nvar<\/span> app =<\/span> express();\r\nvar<\/span> fs =<\/span> require('fs'<\/span>); \/\/require file system object<\/span>\r\n\r\n\/\/ Endpoint to Get a list of users<\/span>\r\napp.get('\/getUsers'<\/span>, function<\/span>(req, res){\r\n    fs.readFile(__dirname +<\/span> \"\/\"<\/span> +<\/span> \"users.json\"<\/span>, 'utf8'<\/span>, function<\/span>(err, data){\r\n        console.log(data);\r\n        res.end(data); \/\/ you can also use res.send()<\/span>\r\n    });\r\n})\r\n\r\n\/\/ Create a server to listen at port 8080<\/span>\r\nvar<\/span> server =<\/span> app.listen(8080<\/span>, function<\/span>(){\r\n    var<\/span> host =<\/span> server.address().address\r\n    var<\/span> port =<\/span> server.address().port\r\n    console.log(\"REST API demo app listening at http:\/\/%s:%s\"<\/span>, host, port)\r\n})\r\n<\/pre>\n
     <\/p>\n
    Now, run the program using the command<\/p>\n
    Node server.js\r\n<\/pre>\n
    Then open your browser and\u00a0 visit http:\/\/localhost:8080<\/p>\n
    You will a list of users which is the content of the users.json file.<\/p>\n
     <\/p>\n
    3. Inserting a New User<\/strong><\/h5>\n
    We would now write the method to insert a new user. To achieve this, we would take three steps:<\/p>\n