(Excel) Compress String Feed to Base64

This example receives incoming text data in chunks, compresses as a stream, and accumulates the compressed data in base64.

The purpose is to demonstrate the BeginCompressStringENC, MoreCompressStringENC, and EndCompressStringENC methods.

Download Excel Class Modules Chilkat Excel Class Modules

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

Dim sbCompressedBase64 As Chilkat.StringBuilder
Set sbCompressedBase64 = Chilkat.NewStringBuilder

Dim compress As Chilkat.Compression
Set compress = Chilkat.NewCompression
compress.Algorithm = "deflate"
compress.Charset = "utf-8"
compress.EncodingMode = "base64"

Dim sbIndex As Chilkat.StringBuilder
Set sbIndex = Chilkat.NewStringBuilder

For i = 0 To 24
    ' Note: It is possible (and normal) for a BeginCompress* or MoreCompress* method to return
    ' an empty string (or 0 bytes).  When this happens, the input data is not lost.  It will be flushed
    ' in a subsequent call.
    sbIndex.Clear 
    success = sbIndex.AppendInt(i)
    If (i = 0) Then
        success = sbCompressedBase64.Append(compress.BeginCompressStringENC(sbIndex.GetAsString()))
    Else
        success = sbCompressedBase64.Append(compress.MoreCompressStringENC(sbIndex.GetAsString()))
    End If

    success = sbCompressedBase64.Append(compress.MoreCompressStringENC(": This is a line of data to be compressed..." & vbCrLf))
Next

' Flush any remaining output.
success = sbCompressedBase64.Append(compress.EndCompressStringENC())

Debug.Print "The base64 encoded compressed text:"
Debug.Print sbCompressedBase64.GetAsString()

' Now decompress in one call:

originalText = compress.DecompressStringENC(sbCompressedBase64.GetAsString())
Debug.Print originalText