(DataFlex) Chilkat Zip API Concepts

This example helps clarify some common misconceptions w/ using the Chilkat Zip API.

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

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoZip
    Boolean iSuccess
    Boolean iSaveExtraPath
    Variant vEntry
    Handle hoEntry
    Integer i
    Integer n
    String sTemp1
    Integer iTemp1

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

    Get Create (RefClass(cComChilkatZip)) To hoZip
    If (Not(IsComObjectCreated(hoZip))) Begin
        Send CreateComObject of hoZip
    End

    // To clarify some concepts, this example will create a new .zip containing 2 files.

    // The NewZip method is called to initialize the zip object to a new and empty state.
    // It does not actually create the .zip file.  It simply intializes the object.
    // if the zip object did not contain anything previously, then this method could be skipped
    // altogether.  It has the side-effect of setting the zip.FileName property.
    Get ComNewZip Of hoZip "test.zip" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoZip To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // The FileName property should now contain "test.zip".  This is the name of the .zip
    // that is written when WriteZip or WriteZipAndClose is called.
    Get ComFileName Of hoZip To sTemp1
    Showln "zip filename = " sTemp1

    // When a file is "appended" to the zip object, we are really just appending a reference
    // to the file in the filesystem.  A "zip entry" is added to the zip object and this entry
    // can be one of several types.  It can point to a file.  It can contain uncompressed binary
    // or text data, it can point to an entry in the already-opened zip (if we had called OpenZip 
    // instead), etc.  

    // Now.. add a reference to a single file by calling AppendOneFileOrDir
    // Note: On Windows, forward slashes are equivalent to backslashes
    Move False To iSaveExtraPath
    Get ComAppendOneFileOrDir Of hoZip "/temp/abc123/HelloWorld123.txt" iSaveExtraPath To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoZip To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // We now have a zip object with one entry, which points to the file /temp/abc123/HelloWorld123.txt
    // If desired, we could change the filename of the zip entry so that when the zip is written,
    // the file has a different name:
    Get ComGetEntryByIndex Of hoZip 0 To vEntry
    If (IsComObject(vEntry)) Begin
        Get Create (RefClass(cComChilkatZipEntry)) To hoEntry
        Set pvComObject Of hoEntry To vEntry
    End
    Set ComFileName Of hoEntry To "helloWorld.txt"
    Send Destroy of hoEntry

    // When the zip is actually written, the entry's data will stream from /temp/abc123/HelloWorld123.txt
    // and be compressed into an entry within the .zip having the filename "helloWorld.txt"

    // Now add another entry, this time from a string containing the file content:
    Get ComAppendString2 Of hoZip "HelloWorld2.txt" "hello world!" "utf-8" To vEntry
    If (IsComObject(vEntry)) Begin
        Get Create (RefClass(cComChilkatZipEntry)) To hoEntry
        Set pvComObject Of hoEntry To vEntry
    End
    Send Destroy of hoEntry

    // Examine the entries in the zip so far..
    // Each entry can be one of the following types:

    // 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. 

    Get ComNumEntries Of hoZip To n
    For i From 0 To (n - 1)

        Get ComGetEntryByIndex Of hoZip i To vEntry
        If (IsComObject(vEntry)) Begin
            Get Create (RefClass(cComChilkatZipEntry)) To hoEntry
            Set pvComObject Of hoEntry To vEntry
        End
        Get ComFileName Of hoEntry To sTemp1
        Get ComEntryType Of hoEntry To iTemp1
        Showln sTemp1 ", type=" iTemp1
        Send Destroy of hoEntry
    Loop

    // Write the "test.zip" file.
    Get ComWriteZip Of hoZip To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoZip To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Our zip object still contains 2 entries, but now they point to the entries within the 
    // test.zip  (We called WriteZip, which writes the .zip but does not close it.  Instead,
    // the entries of the zip object are updated to become "mapped" entries.
    // For example:

    Get ComNumEntries Of hoZip To n
    For i From 0 To (n - 1)

        Get ComGetEntryByIndex Of hoZip i To vEntry
        If (IsComObject(vEntry)) Begin
            Get Create (RefClass(cComChilkatZipEntry)) To hoEntry
            Set pvComObject Of hoEntry To vEntry
        End
        Get ComFileName Of hoEntry To sTemp1
        Get ComEntryType Of hoEntry To iTemp1
        Showln sTemp1 ", type=" iTemp1
        Send Destroy of hoEntry
    Loop

    // Finally, close the zip
    Send ComCloseZip To hoZip


End_Procedure