(DataFlex) Compress and Decompress Base64

Imagine we have data represented as a base64 string. This example demonstrates how to decode, compress, and re-encode to smaller base64 representing the compressed data.

Note: This example requires Chilkat v9.5.0.66 or greater.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    String sStrBase64
    Handle hoCompress
    Variant vBinDat
    Handle hoBinDat
    String sCompressedBase64
    String sDecompressedBase64

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

    Move "VGhlIHF1aWNrIGJyb3duIGZveCBqdW1wZWQgb3ZlciB0aGUgbGF6eSBkb2cuDQpUaGUgcXVpY2sgYnJvd24gZm94IGp1bXBlZCBvdmVyIHRoZSBsYXp5IGRvZy4NClRoZSBxdWljayBicm93biBmb3gganVtcGVkIG92ZXIgdGhlIGxhenkgZG9nLg0KVGhlIHF1aWNrIGJyb3duIGZveCBqdW1wZWQgb3ZlciB0aGUgbGF6eSBkb2cuDQpUaGUgcXVpY2sgYnJvd24gZm94IGp1bXBlZCBvdmVyIHRoZSBsYXp5IGRvZy4NCg0K" To sStrBase64

    Get Create (RefClass(cComChilkatCompression)) To hoCompress
    If (Not(IsComObjectCreated(hoCompress))) Begin
        Send CreateComObject of hoCompress
    End
    Set ComAlgorithm Of hoCompress To "deflate"

    Get Create (RefClass(cComChilkatBinData)) To hoBinDat
    If (Not(IsComObjectCreated(hoBinDat))) Begin
        Send CreateComObject of hoBinDat
    End
    // Load the base64 data into a BinData object.
    // This decodes the base64. The decoded bytes will be contained in the BinData.
    Get ComAppendEncoded Of hoBinDat sStrBase64 "base64" To iSuccess

    // Compress the BinData.
    Get pvComObject of hoBinDat to vBinDat
    Get ComCompressBd Of hoCompress vBinDat To iSuccess

    // Get the compressed data in base64 format:
    Get ComGetEncoded Of hoBinDat "base64" To sCompressedBase64
    Showln "compressed base64:"
    Showln sCompressedBase64

    // The compressed base64 is: C8lIVSgszUzOVkgqyi/PU0jLr1DIKs0tSE1RyC9LLVIoAcrnJFZVKqTkp+vxcoUMYeW8XAA=

    // Now decompress:
    Get ComClear Of hoBinDat To iSuccess
    Get ComAppendEncoded Of hoBinDat sCompressedBase64 "base64" To iSuccess
    Get pvComObject of hoBinDat to vBinDat
    Get ComDecompressBd Of hoCompress vBinDat To iSuccess

    Get ComGetEncoded Of hoBinDat "base64" To sDecompressedBase64
    Showln "decompressed base64:"
    Showln sDecompressedBase64

    // The output is the original data:
    // VGhlIHF1aWNrIGJyb3duIGZveCBqdW1wZWQgb3ZlciB0aGUgbGF6eSBkb2cuDQpUaGUgcXVpY2sgYnJvd24gZm94IGp1bXBlZCBvdmVyIHRoZSBsYXp5IGRvZy4NClRoZSBxdWljayBicm93biBmb3gganVtcGVkIG92ZXIgdGhlIGxhenkgZG9nLg0KVGhlIHF1aWNrIGJyb3duIGZveCBqdW1wZWQgb3ZlciB0aGUgbGF6eSBkb2cuDQpUaGUgcXVpY2sgYnJvd24gZm94IGp1bXBlZCBvdmVyIHRoZSBsYXp5IGRvZy4NCg0K


End_Procedure