Course Content
Backend Development with Node.js and Express.js
Backend Development with Node.js and Express.js
Building the DELETE Post by Id Endpoint
We'll dive into the implementation of the "DELETE POST BY ID" route within the postsRoutes.js
file. This route allows clients to delete a specific post by providing its unique ID.
Route Definition
The code below defines the "DELETE POST BY ID" route using router.delete()
:
router.delete("/post/:id", async (req, res, next) => { ... }
This route handles HTTP DELETE requests with a parameterized :id
in the route path. The :id
parameter is used to identify the post to be deleted. We don't need extra middleware like dataValidation
as we get all the necessary information from the URL parameter.
Extracting the Post ID
We extract the post ID from the request parameters using req.params.id
:
const postId = req.params.id;
This line captures the :id
value from the URL, allowing us to work with it in the subsequent code.
Delete the Post
Here's how we delete the post:
const data = await readData();
const postIndex = data.findIndex((post) => post.id === postId);
if (postIndex === -1) {
return res.status(404).json({ error: "Post not found" });
}
data.splice(postIndex, 1);
await fs.writeFile("./database/posts.json", JSON.stringify(data));
- We begin by reading the existing data from the JSON file using the asynchronous
readData
function, as explained earlier. - We find the index of the post to delete in the
data
array by comparing post IDs. - If the post is not found (i.e.,
postIndex === -1
), we return a 404 (Not Found) response with an error message. - Using the
splice
method, we remove the post data from thedata
array. ThepostIndex
variable determines the position of the post to delete. - The updated
data
array, with the post removed, is then written back to the JSON file to save the changes made during the deletion.
Sending a Response
A JSON response with a status code of 200 (OK) is sent to the client, indicating a successful deletion. The response includes a message confirming that the post was deleted successfully:
res.status(200).json({ message: "Post deleted successfully" });
Error Handling
We wrap the route code in a try-catch block to handle potential errors during data retrieval or request processing. Any errors that occur are logged to the console for debugging purposes:
try {
// ... (code for retrieving and processing data)
} catch (error) {
console.error(error.message);
}
Complete code of the postsRoutes.js file at this step
const express = require("express");
const fs = require("fs/promises");
const validatePostData = require("../middlewares/validateData");
const router = express.Router();
// Function to read data from the JSON file
async function readData() {
try {
// Read the contents of the `posts.json` file
const data = await fs.readFile("./database/posts.json");
// Parse the JSON data into a JavaScript object
return JSON.parse(data);
} catch (error) {
// If an error occurs during reading or parsing, throw the error
throw error;
}
}
// GET ALL POSTS
router.get("/", async (req, res, next) => {
try {
// Call the `readData` function to retrieve the list of posts
const data = await readData();
// Send the retrieved data as the response
res.status(200).send(data);
} catch (error) {
// If an error occurs during data retrieval or sending the response
console.error(error.message); // Log the error to the console for debugging
}
});
// GET POST BY ID
router.get("/post/:id", async (req, res, next) => {
try {
// Extract the post ID from the request parameters
const postId = req.params.id;
// Read data from the JSON file
const data = await readData();
// Find the post with the matching ID
const post = data.find((post) => post.id === postId);
// If the post is not found, send a 404 response
if (!post) {
res.status(404).json({ error: "Post not found" });
} else {
// If the post is found, send it as the response
res.status(200).send(post);
}
} catch (error) {
// Handle errors by logging them and sending an error response
console.error(error.message);
}
});
// CREATE POST
router.post("/", validatePostData, async (req, res, next) => {
try {
const newPost = {
id: Date.now().toString(), // Generate a unique ID for the new post
username: req.body.username,
postTitle: req.body.postTitle,
postContent: req.body.postContent,
};
// Read the existing data
const data = await readData();
// Add the new post to the data
data.push(newPost);
// Write the updated data back to the JSON file
await fs.writeFile("./database/posts.json", JSON.stringify(data));
// Send a success response with the new post
res.status(201).json(newPost);
} catch (error) {
// Handle errors by logging them to the console
console.error(error.message);
}
});
// UPDATE POST BY ID
router.put("/post/:id", validatePostData, async (req, res, next) => {
try {
// Extract the post ID from the request parameters
const postId = req.params.id;
// Extract the updated data from the request body
const updatedData = {
username: req.body.username,
postTitle: req.body.postTitle,
postContent: req.body.postContent,
};
// Read the existing data
const data = await readData();
// Find the index of the post with the specified ID in the data array
const postIndex = data.findIndex((post) => post.id === postId);
// If the post with the specified ID doesn't exist, return a 404 error
if (postIndex === -1) {
return res.status(404).json({ error: "Post not found" });
}
// Update the post data with the new data using spread syntax
data[postIndex] = {
...data[postIndex], // Keep existing data
...updatedData, // Apply updated data
};
// Write the updated data back
await fs.writeFile("./database/posts.json", JSON.stringify(data));
// Send a success response with the updated post
res.status(200).json(data[postIndex]);
} catch (error) {
console.error(error.message);
next(error);
}
});
// DELETE POST BY ID
router.delete("/post/:id", async (req, res, next) => {
try {
// Extract the post ID from the request parameters
const postId = req.params.id;
// Read the existing data
const data = await readData();
// Find the index of the post with the specified ID in the data array
const postIndex = data.findIndex((post) => post.id === postId);
// If the post with the specified ID doesn't exist, return a 404 error
if (postIndex === -1) {
return res.status(404).json({ error: "Post not found" });
}
// Remove the post from the data array using `splice`
data.splice(postIndex, 1);
// Write the updated data back to the data source (e.g., a JSON file)
await fs.writeFile("./database/posts.json", JSON.stringify(data));
// Send a success response with the JSON response indicating successful deletion
res.status(200).json({ message: "Post deleted successfully" });
} catch (error) {
console.error(error.message);
next(error);
}
});
module.exports = router;
Thanks for your feedback!