Read zip files recursively with zip.js

[Venkatesh0625]

I have some zip inside the zip file which i want to read recursively

[gildas-lormeau]

You could use the function below which accepts a ZipReader instance as parameter and returns all the entries recursively.

async function getAllEntries(zipReader, options) {
  let entries = await zipReader.getEntries(options);
  entries = await Promise.all(entries.map(async entry => {
    if (entry.filename.toLowerCase().endsWith(".zip")) {
      const innerZipReader = new zip.ZipReader(new zip.BlobReader(await entry.getData(new zip.BlobWriter())));
      return getAllEntries(innerZipReader, options);
    } else {
      return entry;
    }
  }));
  return entries.flat();
}

Here is below an example of code showing how to use it.

/* global zip, Blob */

"use strict";

const TEXT_CONTENT = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod...";
const TEXT_CONTENT_BLOB = new Blob([TEXT_CONTENT], { type: "text/plain" });

test().catch(error => console.error(error));

async function test() {  
  // creates a zip file containing 3 text files
  let zipWriter = new zip.ZipWriter(new zip.BlobWriter("application/zip"));  
  await zipWriter.add("lorem1.txt", new zip.BlobReader(TEXT_CONTENT_BLOB));  
  await zipWriter.add("lorem2.txt", new zip.BlobReader(TEXT_CONTENT_BLOB));
  await zipWriter.add("lorem3.txt", new zip.BlobReader(TEXT_CONTENT_BLOB));  
  const loremZip1 = await zipWriter.close();  

  // creates a zip file containing 2 text files
  zipWriter = new zip.ZipWriter(new zip.BlobWriter("application/zip"));
  await zipWriter.add("another_lorem1.txt", new zip.BlobReader(TEXT_CONTENT_BLOB));
  await zipWriter.add("another_lorem2.txt", new zip.BlobReader(TEXT_CONTENT_BLOB));
  const loremZip2 = await zipWriter.close();

  // creates a zip file containing the first zip file and a text file
  zipWriter = new zip.ZipWriter(new zip.BlobWriter("application/zip"));
  await zipWriter.add("lorem1.zip", new zip.BlobReader(loremZip1));
  await zipWriter.add("another_lorem3.txt", new zip.BlobReader(TEXT_CONTENT_BLOB));
  const loremZip3 = await zipWriter.close();

  // creates a zip file containing the 2 previous files and a text file
  zipWriter = new zip.ZipWriter(new zip.BlobWriter("application/zip"));
  await zipWriter.add("lorem3.zip", new zip.BlobReader(loremZip3));
  await zipWriter.add("lorem2.zip", new zip.BlobReader(loremZip2));
  await zipWriter.add("yet_another_lorem.txt", new zip.BlobReader(TEXT_CONTENT_BLOB));  
  const compressedFile = await zipWriter.close();

  // get all the entries recursively
  const entries = await getAllEntries(new zip.ZipReader(new zip.BlobReader(compressedFile)));
  document.body.innerHTML = entries.map(entry => entry.filename).join("<br>");
}

async function getAllEntries(zipReader, options) {
  let entries = await zipReader.getEntries(options);
  entries = await Promise.all(entries.map(async entry => {
    if (entry.filename.toLowerCase().endsWith(".zip")) {
      const innerZipReader = new zip.ZipReader(new zip.BlobReader(await entry.getData(new zip.BlobWriter())));
      return getAllEntries(innerZipReader, options);
    } else {
      return entry;
    }
  }));
  return entries.flat();
}

You can run this code here: https://plnkr.co/edit/yhSnJFmsKyq6m4uH

[Venkatesh0625]

Very Thank you!! @gildas-lormeau