(JavaScript) Get Compressed ZIP Entry Data as Base64 Using ZipEntry.CopyToBase64

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This example creates a small ZIP archive containing a text file added from memory, writes the ZIP to disk, re-opens it, and then uses ZipEntry.CopyToBase64 to retrieve the compressed data for the text file as a Base64-encoded string.

The Base64 string returned by CopyToBase64 represents the compressed bytes stored for the entry inside the ZIP archive. It is not the original uncompressed text data.

Note: This example requires Chilkat v11.0.0 or greater.

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

var success = false;

// ------------------------------------------------------------
// First create a sample ZIP archive containing a small text file.

var zip = new CkZip();

success = zip.NewZip("c:/temp/sampleText.zip");
if (success == false) {
    console.log(zip.LastErrorText);
    return;
}

// Add a small text file from memory.
// The text is stored in the ZIP as "hello.txt".
success = zip.AddString("hello.txt","Hello from a ZIP entry!","utf-8");
if (success == false) {
    console.log(zip.LastErrorText);
    return;
}

// Write the ZIP archive to disk and close it.
success = zip.WriteZipAndClose();
if (success == false) {
    console.log(zip.LastErrorText);
    return;
}

// ------------------------------------------------------------
// Now open the ZIP archive we just created.

var zip2 = new CkZip();

success = zip2.OpenZip("c:/temp/sampleText.zip");
if (success == false) {
    console.log(zip2.LastErrorText);
    return;
}

// Get the text file entry.
var entry = new CkZipEntry();

success = zip2.EntryOf("hello.txt",entry);

if (success == false) {
    console.log("Entry not found.");
    return;
}

// Get the compressed ZIP entry data as Base64.
// 
// This is the compressed data stored inside the ZIP file,
// not the uncompressed text "Hello from a ZIP entry!".
var b64 = entry.CopyToBase64();

console.log("Base64 compressed ZIP entry data:");
console.log(b64);

zip2.CloseZip();

console.log("Done.");