# Multer
# Installation
# Multer Installation
npm install multer
# Usage
# Create Multer Middleware
In backend/src/middleware create a file called multer.js
# Define Multer Middleware
backend/src/middleware/multer.js
const multer = require("multer");
const storage = multer.diskStorage({
destination: function (req, file, cb) {
switch (req.baseUrl) {
case "/api/blogs":
cb(null, "uploads/blogs/");
break;
case "/api/auth":
cb(null, "uploads/users/");
break;
default:
cb(null, "uploads/");
break;
}
},
filename: function (req, file, cb) {
let fileExt = file.originalname.split(".").pop();
let fileName = Date.now() + "." + fileExt;
cb(null, fileName);
},
});
const fileFilter = (req, file, cb) => {
// Accept images only
if (file.mimetype.startsWith("image")) {
cb(null, true);
} else {
cb(new Error("Not an image! Please upload only images."), false);
}
};
const upload = multer({
storage: storage,
fileFilter: fileFilter,
limits: {
fileSize: 1024 * 1024 * 5, // 5MB max file size
},
});
module.exports = { upload };
# Add multer middleware to specific route for file/image upload
backend/src/routes/blogs.js
...
const { upload } = require("../middleware/multer");
...
/**
* POST /api/blogs
*/
router.post("/", protect, upload.single("image"), (req, res) => {
blogController.createBlogs(req, res);
});
...
/**
* Put /api/blogs/
*/
router.put("/:id", protect, upload.single("image"), (req, res) => {
blogController.updateBlogByID(req, res);
});
# Update Blogs Controller
...
const createBlogs = async (req, res) => {
try {
console.log(req.body);
const categoryIds = JSON.parse(req?.body?.categories).map((x) => x.id);
const blog = new Blog({
title: req.body.title,
description: req.body.description,
image: req?.file?.path
? req?.protocol + "://" + req?.headers?.host + "/" + req.file.path
: "",
content: JSON.parse(req.body.content),
authorId: req.body.authorId,
categoryIds: categoryIds,
});
const newBlog = await blog.save();
const blogRes = await Blog.findById(newBlog._id)
.populate({
path: "categoryIds",
})
.populate({ path: "authorId" });
res.status(201).json({
message: "Blog created!",
data: blogRes,
});
} catch (error) {
res.status(500).json({ message: error.message, data: {} });
}
};
...
const updateBlogByID = async (req, res) => {
console.log(req.body);
try {
const blog = await Blog.findById(req.params.id)
.populate({
path: "categoryIds",
})
.populate({ path: "authorId" });
if (blog) {
const categoryIds = JSON.parse(req?.body?.categories).map((x) => x.id);
blog.authorId = req?.body?.authorId || blog.authorId;
blog.categoryIds = categoryIds ? categoryIds : blog.categoryIds;
(blog.image = req?.file?.path
? req?.protocol + "://" + req?.headers?.host + "/" + req.file.path
: blog.image),
(blog.title = req?.body?.title || blog.title);
blog.description = req?.body?.description || blog.description;
blog.content = req.body.content ? JSON.parse(req.body.content) : blog.content;
const updatedBlog = await blog.save();
const blogRes = await updatedBlog.populate({
path: "categoryIds",
});
res.status(200).json({ message: "Blog updated!", data: blogRes });
} else {
res.status(404).json({ message: "Blog not found!", data: [] });
}
} catch (error) {
res.status(500).json({ message: error.message, data: {} });
}
};
# Update index.js
backend/src/index.js
...
const path = require("path");
...
app.use("/uploads", express.static(path.join(__dirname, "../uploads")));