{"id":22137,"date":"2020-08-10T15:16:01","date_gmt":"2020-08-10T15:16:01","guid":{"rendered":"http:\/\/node_js_file_upload_to_a_local_server_or_to_the_cloud"},"modified":"2024-06-04T15:59:47","modified_gmt":"2024-06-04T22:59:47","slug":"node_js_file_upload_to_a_local_server_or_to_the_cloud","status":"publish","type":"post","link":"https:\/\/cloudinary.com\/blog\/node_js_file_upload_to_a_local_server_or_to_the_cloud","title":{"rendered":"Node.js File Upload to a Local Server Or to the Cloud"},"content":{"rendered":"

Probably one of the best things to happen to JavaScript developers, Node.js empowers them to write and ship JavaScript on the back end. Thanks to Node.js, front-end developers can become full-stack developers in a snap.<\/p>\n

The procedures below describe how to Node.js file upload\u2019s<\/a> to your local server or to the cloud at Cloudinary.<\/p>\n

Set Up a Node Project<\/h2>\n

First, download and install Node.js on your system<\/a>. Afterwards, set up a Node.js back-end server with a package, such as Express. Do the following:<\/p>\n

    \n
  1. \n

    Create an upload<\/code> directory and run npm init<\/code> there to generate a package.json<\/code> file:<\/p>\n

    npm init\n<\/code><\/span><\/pre>\n<\/li>\n
  2. \n
    In the same directory, install Express:<\/p>\n
    npm install express --save\n<\/code><\/span><\/pre>\n<\/li>\n
  3. \n
    Create an index.js<\/code> file with the code below:<\/p>\n
        const<\/span> express = require<\/span>('express'<\/span>)\n    const<\/span> app = express()\n    const<\/span> port = 3000<\/span>\n\n    app.get('\/'<\/span>, (req, res) => res.json({ message<\/span>: 'Hello World!'<\/span> }))\n\n    app.listen(port, () => console<\/span>.log(`This is the beginning of the Node File Upload App`<\/span>))\n<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n<\/li>\n
  4. \n
    Run the project with the command node index.js<\/code>.<\/p>\n
    Your back-end server is now up and running.<\/p>\n
    \"upload\"<\/p>\n
    Afterwards, multer<\/code> creates an images<\/code> directory in which to display the details of the recently uploaded file in your console. See this example:<\/p>\n
    \"node<\/p>\n
    For simultaneous multiple file uploads, just change fileUpload.single<\/code> to fileUpload.array<\/code>:<\/p>\n<\/li>\n<\/ol>\n
    ...\napp.post('\/photos\/upload'<\/span>, fileUpload.array('image'<\/span>, 5<\/span>), function<\/span> (req, res, next<\/span>) <\/span>{\n      console<\/span>.log(\"Images \"<\/span>, req.file);  \n})\n<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n
    5<\/code> above can be any numeric value, denoting the number of files you plan to upload.<\/p>\n
    Step 2: Set up file uploads to Cloudinary<\/h3>\n
    Completing step 1 enables you to upload files to your local server<\/a>. For multiple files, best store them in a central location like Cloudinary and behind a content delivery network (CDN) at scale for efficient retrieval and delivery to users.<\/p>\n
    This step establishes the mechanics for uploading files to Cloudinary.<\/p>\n
    As a prerequisite, sign up for a free account on Cloudinary<\/a>. Note your cloud name and API keys on the dashboard.<\/p>\n
    \"media<\/p>\n
    Now do the following.<\/p>\n
      \n
    1. \n
      Rewrite multer<\/code> to accept zero arguments:<\/p>\n
      const<\/span> fileUpload = multer()\n<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n
      Instead of being written to a local directory, the uploaded files now reside in memory temporarily as a buffer.<\/p>\n<\/li>\n
    2. \n
      Install Cloudinary\u2019s Node.js SDK<\/a> and the streamifier<\/code> library:<\/p>\n
      npm install cloudinary \nnpm install streamifier\n<\/code><\/span><\/pre>\n<\/li>\n
    3. \n
      Make the cloudinary<\/code> and streamifier<\/code> required libraries in your codebase:<\/p>\n
      ...\nconst<\/span> cloudinary = require<\/span>('cloudinary'<\/span>).v2\nconst<\/span> streamifier = require<\/span>('streamifier'<\/span>)\n...\n<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n<\/li>\n
    4. \n
      Rewrite the \/upload<\/code> endpoint code to upload files to Cloudinary:<\/p>\n
      app.post('\/upload'<\/span>, fileUpload.single('image'<\/span>), function<\/span> (req, res, next<\/span>) <\/span>{\n    let<\/span> streamUpload = (req<\/span>) =><\/span> {\n        return<\/span> new<\/span> Promise<\/span>((resolve, reject<\/span>) =><\/span> {\n            let<\/span> stream = cloudinary.uploader.upload_stream(\n              (error, result<\/span>) =><\/span> {\n                if<\/span> (result) {\n                  resolve(result);\n                } else<\/span> {\n                  reject(error);\n                }\n              }\n            );\n\n          streamifier.createReadStream(req.file.buffer).pipe(stream);\n        });\n    };\n\n    async<\/span> function<\/span> upload<\/span>(req<\/span>) <\/span>{\n        let<\/span> result = await<\/span> streamUpload(req);\n        console<\/span>.log(result);\n    }\n\n    upload(req);\n});\n<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n<\/li>\n<\/ol>\n
      Recall that you rewrote multer<\/code> earlier to process and store uploaded files temporarily as a buffer. streamifier<\/code> now converts the uploaded buffer to a readable stream, after which Cloudinary\u2019s upload_stream<\/code> method streams directly to the cloud.<\/p>\n
      The returned result looks like this, complete with the details on the recently uploaded file:<\/p>\n
      \"node.js<\/p>\n
      Now you can fetch the URL from the JSON response and store it in the database. Mission accomplished.<\/p>\n
      A Word About Cloudinary\u2019s Node.js SDK<\/h2>\n
      Besides uploading images and videos, Cloudinary\u2019s Node.js SDK can also transform, optimizatize, and deliver them. You can seamlessly integrate those capabilities with your Node.js app. For details, see the related documentation<\/a>.<\/p>\n
      Want to Learn More About File Uploads?<\/h2>\n