Visual Basic Programming Code Examples

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Creating an internet cookie



Creating an internet cookie

The following code demonstates how to create internet cookies. Please read the "Notes" for an explaination of the current limitations of creating cookies using the wininet dll.

Option Explicit
Private Declare Function InternetSetCookie Lib "wininet.dll" Alias "InternetSetCookieA" (ByVal lpszUrlName As String, ByVal lpszCookieName As String, ByVal lpszCookieData As String) As Boolean
Private Declare Function InternetGetCookie Lib "wininet.dll" Alias "InternetGetCookieA" (ByVal lpszUrlName As String, ByVal lpszCookieName As String, ByVal lpszCookieData As String, lpdwSize As Long) As Boolean

'Purpose   :    Creates an internet cookie
'Inputs    :    sURL                    The URL to create the cookie for.
'               sCookieName             The name of the cookie.
'               sCookieData             The data to store in the cookie
'Outputs   :    Returns True if succeeded in creating the cookie.

'Notes     :    Cookies created by this function without an expiration date are stored in memory and are
'               available only in the same process that created them. Cookies that include an expiration
'               date are stored in the windows\cookies directory.
'               Creating a new cookie might cause a dialog box to appear on the screen if the appropriate
'               registry value, AllowCookies, is set.


Function InternetCookieCreate(sURL As String, sCookieName As String, sCookieData As String) As Boolean
    On Error GoTo ErrFailed
    InternetCookieCreate = InternetSetCookie(sURL, sCookieName, sCookieData)
    Exit Function

ErrFailed:
    Debug.Print Err.Description
    InternetCookieCreate = False
End Function


'Purpose   :    Returns ALL the data from an internet cookie
'Inputs    :    sURL                    The URL to create the cookie for.
'               sCookieName             Not supported in the current version of the wininet dll
'               sCookieData             The data to store in the cookie
'Outputs   :    Returns True if succeeded in creating the cookie.
'Notes     :

Function InternetCookieGet(sURL As String, sCookieName As String, sCookieData As String) As String
    Const clMaxCookieLen = 5012     'Arbitary limit
    Dim sResult As String * clMaxCookieLen
    Dim bRet As Boolean, lLen As Long
    
    On Error GoTo ErrFailed
    lLen = clMaxCookieLen
    bRet = InternetGetCookie(sURL, sCookieName, sResult, lLen)
    If bRet Then
        InternetCookieGet = Left$(sResult, lLen)
    End If
    Exit Function

ErrFailed:
    Debug.Print Err.Description
    InternetCookieGet = ""
End Function

'Demonstration routine
Sub Test()
    InternetCookieCreate "http://Example", "Red", "Test Cookie"
    Debug.Print InternetCookieGet("http://Example", "", "Test Cookie")
End Sub