(JavaScript) Control Stored ZIP Paths Using AppendFromDir and saveExtraPath

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This example demonstrates how the AppendFromDir property and the saveExtraPath argument work together to determine the stored paths of files within a ZIP archive.

The example adds the same local filesystem file three times, but stores it in the ZIP archive using three different paths.

The local filesystem file is:

/temp/a/hamlet.xml

The resulting ZIP archive contains:

hamlet.xml
a/hamlet.xml
temp/a/hamlet.xml

The example demonstrates:

• How saveExtraPath controls whether path information is stored in the ZIP archive
• How AppendFromDir establishes the base directory used for relative file paths
• How the same filesystem file can be stored in a ZIP archive using different relative paths
• That methods such as AddFile initially add only references to filesystem files, and that the actual file reading and compression occur later when WriteZipAndClose is called

The example also illustrates an important rule: when AppendFromDir is set, the filename passed to AddFile should normally be a relative path rather than a fully qualified absolute path.

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;

success = false;

var zip = new CkZip();

// Initialize the Zip object and set the output filename.
// The .zip file is not created until WriteZip or WriteZipAndClose is called.
success = zip.NewZip("myZip.zip");
if (success == false) {
    console.log(zip.LastErrorText);
    return;
}

// This example adds the same local filesystem file three times,
// each time using a different stored path in the ZIP archive.
// 
// The local file is:
// 
//     /temp/a/hamlet.xml
// 
// The ZIP will contain:
// 
//     hamlet.xml
//     a/hamlet.xml
//     temp/a/hamlet.xml
// 

// ------------------------------------------------------------
// Case 1:
// Add the file using only the filename.
// 
// AddFile adds a reference to the file in the local filesystem.
// The file is not read or compressed at this point.  The referenced
// file is consumed later when WriteZipAndClose is called.
var saveExtraPath = false;

success = zip.AddFile("/temp/a/hamlet.xml",saveExtraPath);
if (success == false) {
    console.log(zip.LastErrorText);
    return;
}

// Because saveExtraPath = false, only the filename is stored
// in the ZIP archive:
// 
//     hamlet.xml
// 

// ------------------------------------------------------------
// Case 2:
// Store the path "a/hamlet.xml" in the ZIP archive.
// 
// AppendFromDir specifies the base directory for relative file paths.
// The AppendFromDir path itself is not stored in the ZIP.
// 
// Because AppendFromDir is set to "/temp", the relative path
// "a/hamlet.xml" refers to the local filesystem file:
// 
//     /temp/a/hamlet.xml
// 
// Because saveExtraPath = true, the relative path is stored
// in the ZIP as:
// 
//     a/hamlet.xml
// 
zip.AppendFromDir = "/temp";

saveExtraPath = true;

success = zip.AddFile("a/hamlet.xml",saveExtraPath);
if (success == false) {
    console.log(zip.LastErrorText);
    return;
}

// ------------------------------------------------------------
// Case 3:
// Store the path "temp/a/hamlet.xml" in the ZIP archive.
// 
// AppendFromDir is changed to "/" so that the relative path
// "temp/a/hamlet.xml" again refers to the same local filesystem file:
// 
//     /temp/a/hamlet.xml
// 
// Because saveExtraPath = true, the stored ZIP path is:
// 
//     temp/a/hamlet.xml
// 
zip.AppendFromDir = "/";

saveExtraPath = true;

success = zip.AddFile("temp/a/hamlet.xml",saveExtraPath);
if (success == false) {
    console.log(zip.LastErrorText);
    return;
}

// ------------------------------------------------------------
// Write the ZIP archive.
// 
// This is where the referenced file is actually read from disk
// and compressed into the .zip archive.
// 
// The resulting ZIP contains the same file three times,
// each with a different stored path:
// 
//     hamlet.xml
//     a/hamlet.xml
//     temp/a/hamlet.xml
// 
success = zip.WriteZipAndClose();
if (success == false) {
    console.log(zip.LastErrorText);
    return;
}

console.log("ZIP archive created successfully.");