(DataFlex) Get the Last-Modified Date Before HTTP Download

Demonstrates how to send a HEAD request to get the last-modified date of a file on a web server (without downloading the file).

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 hoHttp
    Variant vResp
    Handle hoResp
    String sLastModStr
    Handle hoCkdt
    Variant vDt
    Handle hoDt
    String sTemp1
    Integer iTemp1
    Integer iTemp2
    Integer iTemp3
    Boolean bTemp1

    Move False To iSuccess

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

    Get Create (RefClass(cComChilkatHttp)) To hoHttp
    If (Not(IsComObjectCreated(hoHttp))) Begin
        Send CreateComObject of hoHttp
    End

    Get Create (RefClass(cComChilkatHttpResponse)) To hoResp
    If (Not(IsComObjectCreated(hoResp))) Begin
        Send CreateComObject of hoResp
    End
    Get pvComObject of hoResp to vResp
    Get ComHttpNoBody Of hoHttp "HEAD" "https://www.chilkatsoft.com/hamlet.xml" vResp To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoHttp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Examine the response header.
    Get ComHeader Of hoResp To sTemp1
    Showln sTemp1

    // Here is a sample response header:

    // 	Content-Length: 279658
    // 	Content-Type: text/xml
    // 	Last-Modified: Thu, 12 May 2016 15:14:08 GMT
    // 	Accept-Ranges: bytes
    // 	ETag: "c1cd8bee60acd11:0"
    // 	Server: Microsoft-IIS/8.5
    // 	X-Powered-By: ASP.NET
    // 	X-Powered-By-Plesk: PleskWin
    // 	Date: Thu, 25 Jul 2019 16:40:54 GMT

    // Get the Last-Modified header.
    Get ComGetHeaderField Of hoResp "Last-Modified" To sLastModStr
    // If the header exists...
    Get ComLastMethodSuccess Of hoResp To bTemp1
    If (bTemp1 = True) Begin
        // Parse the RFC822 format date/time string
        Get Create (RefClass(cComCkDateTime)) To hoCkdt
        If (Not(IsComObjectCreated(hoCkdt))) Begin
            Send CreateComObject of hoCkdt
        End
        Get ComSetFromRfc822 Of hoCkdt sLastModStr To iSuccess

        // If we want to access individual date/time parts (in the local timezone)
        Get Create (RefClass(cComChilkatDtObj)) To hoDt
        If (Not(IsComObjectCreated(hoDt))) Begin
            Send CreateComObject of hoDt
        End
        Get pvComObject of hoDt to vDt
        Send ComToDtObj To hoCkdt True vDt

        Get ComDay Of hoDt To iTemp1
        Get ComMonth Of hoDt To iTemp2
        Get ComYear Of hoDt To iTemp3
        Showln "day/month/year = " iTemp1 "/" iTemp2 "/" iTemp3
    End



End_Procedure