(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).

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

Use ChilkatAx-win32.pkg

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

    // 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 ComGetHead Of hoHttp "https://www.chilkatsoft.com/hamlet.xml" To vResp
    If (IsComObject(vResp)) Begin
        Get Create (RefClass(cComChilkatHttpResponse)) To hoResp
        Set pvComObject Of hoResp To vResp
    End
    Get ComLastMethodSuccess Of hoHttp To bTemp1
    If (bTemp1 = 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 ComGetDtObj Of hoCkdt True To vDt
        If (IsComObject(vDt)) Begin
            Get Create (RefClass(cComChilkatDtObj)) To hoDt
            Set pvComObject Of hoDt To vDt
        End
        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
        Send Destroy of hoDt
    End

    Send Destroy of hoResp


End_Procedure