Question

Technologies:

javascript

npm

Tolerim

21 hours ago

How can I use JavaScript npm to parse multipart/form-data?

As a JavaScript developer, I need to find a way to parse json files in a multipart/form-data format and save them as separate files using an available NPM script. The files need to be split into individual parts. Can anyone provide me with some guidance to accomplish this? Below is an example of the json files:

{
    "@timestamp": "2023-04-28T18:54:32.204432Z",
    "user_agent": {
        "original": "Jersey/2.31 (HttpUrlConnection 1.8.0_121)"
    },
    "host": {
        "ip": "172.20.10.2"
    },
    "message": "--Boundary66157566581682708071578\r\nContent-Type: multipart/form-data\r\nContent-Disposition: form-data; filename=\"123.json\"; name=\"file\"\r\n\r\n{\"firmware\":{\"version\":\"1.0.0\"},\"ENABLED\":false,\"SEQUENCE\":1,\"METHOD\":417}\n\r\n--Boundary66157566581682708071578\r\nContent-Type: multipart/form-data\r\nContent-Disposition: form-data; filename=\"123.json\"; name=\"file\"\r\n\r\n{\"firmware\":{\"version\":\"1.0.0\"},\"ENABLED\":false,\"SEQUENCE\":1,\"METHOD\":417}",
    "http": {
        "request": {
            "body": {
                "bytes": "1195069"
            },
            "mimetype": "multipart/form-data;boundary=Boundary66157566581682708071578"
        },
        "method": "POST",
        "version": "HTTP/1.1"
    }
}

Any help is much appreciated!

Answers(1)

Accepted Answer

To achieve this, you can use the multiparty module of Node.js. You can install it using the following command:

npm install multiparty

Here's an example code snippet that shows how you can parse the multipart/form-data files and store them as separate files:

const multiparty = require('multiparty');
const fs = require('fs');

// Assuming that the JSON files are sent as a part of a form-data request
const form = new multiparty.Form();

form.parse(request, (err, fields, files) => {
  if (err) throw err;

  // files object contains all the files that were sent in the request
  // Loop through the files and write them to separate files
  for (const file of files.file) {
    const fileName = file.originalFilename.replace('.json', '');
    const fileContent = fs.readFileSync(file.path);
    fs.writeFileSync(`${fileName}.json`, fileContent);
  }
});

In this example, we first import the required modules (multiparty and fs). We then create a new instance of multiparty.Form() and call its parse method with the request object as the first argument. The second callback function is called after all the form data is parsed. Inside the callback function, we loop through all the files using a for loop. We first create a new file name for each file by removing the .json extension from the original file name. We then read the content of the file using fs.readFileSync() and write it to a new file with the new file name using fs.writeFileSync(). Note that this code assumes that each file has a unique name, otherwise, files with the same name will overwrite each other.