React Native

Unzip a Text File Entry into a StringBuilder Using ZipEntry.UnzipToSb

See more Zip Examples

This example demonstrates how to use the ZipEntry.UnzipToSb method to inflate a text file entry directly into a StringBuilder object.

The ZIP entry is uncompressed entirely in memory and appended to the StringBuilder without creating a temporary file on disk.

This is useful when:

• Processing text files directly in memory
• Avoiding temporary filesystem files
• Reading configuration files, JSON, XML, CSV, or source code from ZIP archives
• Automatically converting line endings while inflating the text

The srcCharset argument specifies how the uncompressed bytes should be interpreted, such as:

• utf-8
• utf-16
• windows-1252

The lineEndingBehavior argument controls line-ending conversion:

• 0 — Leave line endings unchanged
• 1 — Convert all line endings to bare LF
• 2 — Convert all line endings to CRLF

Suppose the ZIP archive contains:

config/settings.json

The example inflates the JSON file directly into a StringBuilder.

React Native

import { StringBuilder, Zip, ZipEntry } from '@chilkat/react-native'

async function chilkatExample() {
  let success = false;

  const zip = new Zip();

  // Open an existing ZIP archive.
  try {
    await zip.openZipAsync('qa_data/zips/configFiles.zip');
  } catch {
    console.log(zip.lastErrorText);
    return;
  }

  // Locate the JSON file entry within the ZIP archive.
  const entry = new ZipEntry();

  success = zip.entryOf('config/settings.json', entry);
  if (!success) {
    console.log('ZIP entry not found.');
    zip.closeZip();
    return;
  }

  // ------------------------------------------------------------
  // Inflate the ZIP entry directly into a StringBuilder.
  // 
  // The uncompressed text is appended to the StringBuilder.
  // 
  const sb = new StringBuilder();

  // Leave line endings unchanged.
  const lineEndingBehavior = 0;

  // Interpret the uncompressed bytes as UTF-8 text.
  const srcCharset = 'utf-8';

  try {
    await entry.unzipToSbAsync(lineEndingBehavior, srcCharset, sb);
  } catch {
    console.log(entry.lastErrorText);
    return;
  }

  console.log('Uncompressed text:');
  console.log('');
  console.log(sb.getAsString());

  zip.closeZip();

  console.log('Done.');
}