(DataFlex) Chilkat Zip API Concepts

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

Note: This example requires Chilkat v11.0.0 or greater.

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

Use ChilkatAx-win32.pkg

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

    Move False To iSuccess

    // 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 = False) 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 AddFile
    // Note: On Windows, forward slashes are equivalent to backslashes
    Move False To iSaveExtraPath
    Get ComAddFile Of hoZip "/temp/abc123/HelloWorld123.txt" iSaveExtraPath To iSuccess
    If (iSuccess = False) 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 Create (RefClass(cComChilkatZipEntry)) To hoEntry
    If (Not(IsComObjectCreated(hoEntry))) Begin
        Send CreateComObject of hoEntry
    End
    Get pvComObject of hoEntry to vEntry
    Get ComEntryAt Of hoZip 0 vEntry To iSuccess
    Set ComFileName Of hoEntry To "helloWorld.txt"

    // 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 ComAddString Of hoZip "HelloWorld2.txt" "hello world!" "utf-8" To iSuccess

    // 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, AddFile, 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 AddEmpty. 

    Get ComNumEntries Of hoZip To n
    For i From 0 To (n - 1)
        Get pvComObject of hoEntry to vEntry
        Get ComEntryAt Of hoZip i vEntry To iSuccess
        Get ComFileName Of hoEntry To sTemp1
        Get ComEntryType Of hoEntry To iTemp1
        Showln sTemp1 ", type=" iTemp1
    Loop

    // Write the "test.zip" file.
    Get ComWriteZip Of hoZip To iSuccess
    If (iSuccess = False) 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 pvComObject of hoEntry to vEntry
        Get ComEntryAt Of hoZip i vEntry To iSuccess
        Get ComFileName Of hoEntry To sTemp1
        Get ComEntryType Of hoEntry To iTemp1
        Showln sTemp1 ", type=" iTemp1
    Loop

    // Finally, close the zip
    Send ComCloseZip To hoZip


End_Procedure