React Native

Enable FTP MODE Z Compression

Demonstrates the Chilkat Ftp2.SetModeZ method, which enables MODE Z compression for subsequent data connections. It takes no arguments. Call it after connecting and only when the HasModeZ property is true.

Background: MODE Z compresses data on the fly (using zlib) as it crosses the wire, which can meaningfully speed up transfers of compressible content — text, HTML, logs — over a slow link. It is a server extension, so check HasModeZ first and expect it to be unavailable on many servers. There is little benefit for already-compressed data such as images or archives, where the CPU cost of compression buys almost nothing.

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React Native

import { Ftp2 } from '@chilkat/react-native'

async function chilkatExample() {
  // Demonstrates the Ftp2.SetModeZ method, which enables MODE Z compression for subsequent data
  // connections.  It takes no arguments.  Call it after connecting, and only when the HasModeZ
  // property indicates the server supports it.

  const ftp = new Ftp2();

  ftp.hostname = 'ftp.example.com';
  ftp.username = 'myFtpLogin';

  // Normally you would not hard-code the password in source.  You should instead obtain it
  // from an interactive prompt, environment variable, or a secrets vault.
  ftp.password = 'myPassword';

  try {
    await ftp.connectAsync();
  } catch {
    console.log(ftp.lastErrorText);
    return;
  }

  try {
    await ftp.changeRemoteDirAsync('public_html');
  } catch {
    console.log(ftp.lastErrorText);
    return;
  }

  // Only enable compression if the server advertises MODE Z support.
  if (ftp.hasModeZ) {
    try {
      await ftp.setModeZAsync();
    } catch {
      console.log(ftp.lastErrorText);
      return;
    }

    console.log('MODE Z compression enabled.');
  } else {
    console.log('The server does not support MODE Z.');
  }

  // Subsequent uploads, downloads, and listings are transferred compressed.

  try {
    await ftp.disconnectAsync();
  } catch {
    console.log(ftp.lastErrorText);
    return;
  }
}