(Node.js) Zip Append Files and Entry Type

See more Zip Examples

Demonstrates appending files to a zip object for writing a .zip. Also explains the "entry type".

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    var success;

    var zip = new chilkat.Zip();
    // entry: ZipEntry
    var entry;

    var zipPath = "c:/temp/qa_output/out.zip";

    // Initialize the zip object with the path of the .zip to be created.
    zip.NewZip(zipPath);

    // Recursively append to the zip object the paths of the files and directories in a directory tree.
    // At this point we are not creating the .zip, nor are we reading the contents of the files.
    // We are simply appending references to the files and directories in the local filesystem
    // that will get processed when WriteZip is called.
    var recurse = true;
    var saveExtraPath = false;
    var archiveOnly = false;
    var includeHidden = true;
    var includeSystem = false;
    success = zip.AppendFilesEx("c:/temp/files_to_zip",recurse,saveExtraPath,archiveOnly,includeHidden,includeSystem);
    if (success == false) {
        console.log(zip.LastErrorText);
        return;
    }

    // Note: We can iterate over the references to the files that will be processed when zipping:
    var count = zip.NumEntries;
    var i = 0;
    while (i < count) {
        entry = zip.GetEntryByIndex(i);
        console.log(entry.FileName + " entryType = " + entry.EntryType);

        i = i+1;
    }

    console.log("----");

    // Sample output for the above loop:
    // The entry type = 1, because these are entries that are references to files in the local filesystem
    // that are to be processed when the zip is written.

    // hamlet.xml entryType = 1
    // hello.pdf entryType = 1
    // ...
    // ...

    // Possible entry type values:
    // 0 - Mapped Entry: An entry in an existing Zip file.
    // 1 - File Entry: A file not yet in memory, but referenced. These entries are added by calling AppendFiles, AppendFilesEx, AppendOneFileOrDir, etc.
    // 2 - Data Entry: An entry containing uncompressed data from memory. These entries are added by calling AppendData, AppendString, etc.
    // 3 - Null Entry: An entry that no longer exists in the .zip.
    // 4 - New Directory Entry: A directory entry added by calling AppendNewDir. 

    // The application can continue to add additional entries.
    // For example:
    // eTemp: ZipEntry
    var eTemp = zip.AppendString("helloWorld.txt","Hello World");

    // Now let's have a look at what will get zipped when we write the zip:
    count = zip.NumEntries;
    i = 0;
    while (i < count) {
        entry = zip.GetEntryByIndex(i);
        console.log(entry.FileName + " entryType = " + entry.EntryType);

        i = i+1;
    }

    console.log("----");

    // You can see that "helloWorld.txt" is added. 
    // Its entryType = 2, which means it is in-memory data (it is not a reference to a file in the local filesystem).

    // hamlet.xml entryType = 1
    // hello.pdf entryType = 1
    // ...
    // ...
    // helloWorld.txt entryType = 2

    // ----------------------------------------------------------------------------
    // Now we'll write the zip to a .zip file.
    zip.FileName = zipPath;
    success = zip.WriteZip();
    if (success == false) {
        console.log(zip.LastErrorText);
        return;
    }

    // Let's look again at the entries in the .zip
    count = zip.NumEntries;
    i = 0;
    while (i < count) {
        entry = zip.GetEntryByIndex(i);
        console.log(entry.FileName + " entryType = " + entry.EntryType);

        i = i+1;
    }

    console.log("----");

    // After writing the .zip, the entry types change to 0.
    // Entry type 0 indicates that it's a "mapped entry", which is an entry in an existing (and currently open) .zip file.

    // hamlet.xml entryType = 0
    // hello.pdf entryType = 0
    // ...
    // ...
    // helloWorld.txt entryType = 0

    // ----------------------------------------------------------------------------
    // If desired, we could continue adding additional entries of any kind (files or data) to the currently open .zip archive...

    eTemp = zip.AppendString("helloWorld2.txt","Hello World 2");

    // Write the .zip, including the new entries..
    success = zip.WriteZip();
    if (success == false) {
        console.log(zip.LastErrorText);
        return;
    }

    // Finally, let's look again at the entries in the .zip
    count = zip.NumEntries;
    i = 0;
    while (i < count) {
        entry = zip.GetEntryByIndex(i);
        console.log(entry.FileName + " entryType = " + entry.EntryType);

        i = i+1;
    }

    console.log("----");

    // hamlet.xml entryType = 0
    // hello.pdf entryType = 0
    // ...
    // ...
    // helloWorld.txt entryType = 0
    // helloWorld2.txt entryType = 0

    zip.CloseZip();

    console.log("Success");

}

chilkatExample();