React Native

Compress and Decompress Hex String

See more Compression Examples

Imagine we have data represented as a hex string. This example demonstrates how to decode, compress, and re-encode to a smaller hex string representing the compressed data. An even better choice is to re-encode to a more compact encoding such as base64.

Note: This example requires Chilkat v9.5.0.66 or greater.

React Native

import { BinData, Compression } from '@chilkat/react-native'

async function chilkatExample() {
  // This example assumes the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  const strHex = '54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A0D0A';

  const compress = new Compression();
  compress.algorithm = 'deflate';

  const binDat = new BinData();
  // Load the hex string into a BinData object.
  // This decodes the hexidecimal. The decoded bytes will be contained in the BinData.
  binDat.appendEncoded(strHex, 'hex');

  // Compress the BinData.
  await compress.compressBdAsync(binDat);

  // Get the compressed data in hex format:
  const compressedHex = binDat.getEncoded('hex');
  console.log('compressed hex:');
  console.log(compressedHex);

  // The compressed hex is: 0BC94855282CCD4CCE56482ACA2FCF5348CBAF50C82ACD2D484D51C82F4B2D522801CAE72456552AA4E4A7EBF172850C61E5BC5C00

  // Even better, get the compressed data in base64 format:
  // (base64url and modbase64 are other valid choices...)
  const compressedBase64 = binDat.getEncoded('base64');
  console.log('compressed base64:');
  console.log(compressedBase64);

  // The compressed base64 is: C8lIVSgszUzOVkgqyi/PU0jLr1DIKs0tSE1RyC9LLVIoAcrnJFZVKqTkp+vxcoUMYeW8XAA=

  // Now decompress:
  binDat.clear();
  binDat.appendEncoded(compressedHex, 'hex');
  await compress.decompressBdAsync(binDat);

  const decompressedHex = binDat.getEncoded('hex');
  console.log('decompressed hex:');
  console.log(decompressedHex);

  // The output is the original hex string:
  // 54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A0D0A
}