README.md

Node File System, Building a Server, and Using Express

Objective: Gain practical experience with the Node.js File System module, building servers, and using Express for routing.

Tasks Overview

• File System Task: Learn to read and write files.
• Building a Server: Create a server that renders HTML.
• Express Routing: Implement routing with Express.
• PUT Request Implementation: Handle PUT requests to update JSON data.

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File System Task

Goal: Manipulate text files and HTML with Node.js.

1. In the node-server folder, create textfile.txt.
2. Add sample text to textfile.txt.
3. Run node src/index.js to output file contents in the console.
4. Create index.html with basic HTML structure.
5. Modify src/index.js to serve index.html, and rerun the server.

---

Building a Server

Goal: Build a server to render HTML content.

1. Enhance index.html with more complex HTML.

2. Use the following code in src/index.js to serve index.html:

   var http = require("http"),
     fs = require("fs");
   
   var server = http
     .createServer(function (request, response) {
       fs.readFile("./index.html", function (err, html) {
         if (err) {
           throw err;
         }
         response.writeHeader(200, { "Content-Type": "text/html" });
         response.write(html);
         response.end();
       });
     })
     .listen(8080);

3. Start the server and navigate to http://localhost:8080/ to see the HTML page.

4. Modify the server for different URL conditions, returning a 404 status for unmatched routes.

Visual Aid for Building a Server

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Express Routing

Goal: Implement Express routing to handle JSON data.

1. Install Express dependencies: Run npm install in the terminal.

2. Open server.js and set up Express:

   var express = require("express");
   var app = express();
   app.use(express.json()); // For parsing JSON requests

3. Add a GET route in server.js to return profiles.json content at http://localhost:8080/profiles.

4. Test the server with node src/server.js and visit the URL in a browser or Postman.

5. Implement an additional GET route for http://localhost:8080/profiles/view to return profile information as HTML.

Expected Results for Express Routing

Visiting http://localhost:8080/profiles/view displays profile names and bios as HTML.

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PUT Request Implementation

Goal: Update profiles.json via PUT requests.

Steps for PUT Request

1. Open server.js in the logger folder.

2. Implement a PUT route /api/profiles/:id.

3. Update profiles.json with new data upon receiving a PUT request.

4. Test using Postman with the following JSON data:

   {
     "firstname": "Jessica",
     "lastname": "Jones",
     "age": 35
   }

Handling and Testing

• Ensure correct functionality by replacing the specified profile in profiles.json.
• Handle non-existent IDs with a 404 Not Found status.

Expected Outcomes

• Success: PUT http://localhost:3000/profiles/1 updates the profile and returns 200 OK.
• Failure: PUT http://localhost:3000/profiles/567 returns 404 Not Found if the ID does not exist.

Conclusion

This README provides a step-by-step guide to understand file handling, server setup, Express routing, and PUT request handling in Node.js.