(SQL Server) 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

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- This example requires the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    DECLARE @zip int
    -- Use "Chilkat_9_5_0.Zip" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Zip', @zip OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    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.
    DECLARE @success int
    EXEC sp_OAMethod @zip, 'NewZip', @success OUT, 'test.zip'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @zip, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @zip
        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.

    EXEC sp_OAGetProperty @zip, 'FileName', @sTmp0 OUT
    PRINT 'zip filename = ' + @sTmp0

    -- 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
    DECLARE @saveExtraPath int
    SELECT @saveExtraPath = 0
    EXEC sp_OAMethod @zip, 'AppendOneFileOrDir', @success OUT, '/temp/abc123/HelloWorld123.txt', @saveExtraPath
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @zip, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @zip
        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:
    DECLARE @entry int
    EXEC sp_OAMethod @zip, 'GetEntryByIndex', @entry OUT, 0
    EXEC sp_OASetProperty @entry, 'FileName', 'helloWorld.txt'
    EXEC @hr = sp_OADestroy @entry

    -- 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:
    EXEC sp_OAMethod @zip, 'AppendString2', @entry OUT, 'HelloWorld2.txt', 'hello world!', 'utf-8'
    EXEC @hr = sp_OADestroy @entry

    -- 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. 

    DECLARE @i int

    DECLARE @n int
    EXEC sp_OAGetProperty @zip, 'NumEntries', @n OUT
    SELECT @i = 0
    WHILE @i <= @n - 1
      BEGIN

        EXEC sp_OAMethod @zip, 'GetEntryByIndex', @entry OUT, @i
        EXEC sp_OAGetProperty @entry, 'FileName', @sTmp0 OUT

        EXEC sp_OAGetProperty @entry, 'EntryType', @iTmp0 OUT
        PRINT @sTmp0 + ', type=' + @iTmp0
        EXEC @hr = sp_OADestroy @entry

        SELECT @i = @i + 1
      END

    -- Write the "test.zip" file.
    EXEC sp_OAMethod @zip, 'WriteZip', @success OUT
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @zip, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @zip
        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:

    EXEC sp_OAGetProperty @zip, 'NumEntries', @n OUT
    SELECT @i = 0
    WHILE @i <= @n - 1
      BEGIN

        EXEC sp_OAMethod @zip, 'GetEntryByIndex', @entry OUT, @i
        EXEC sp_OAGetProperty @entry, 'FileName', @sTmp0 OUT

        EXEC sp_OAGetProperty @entry, 'EntryType', @iTmp0 OUT
        PRINT @sTmp0 + ', type=' + @iTmp0
        EXEC @hr = sp_OADestroy @entry

        SELECT @i = @i + 1
      END

    -- Finally, close the zip
    EXEC sp_OAMethod @zip, 'CloseZip', NULL

    EXEC @hr = sp_OADestroy @zip


END
GO