Implementation

by Peter Foti, 2002/02/04

We explain here how to manipulate cookies with:

server side functions for getting the cookie.
client side javascript code for setting, getting and deleting the cookies.

Some of this code is almost a duplication of the websGetRequestDir function.

:!: The GoAhead webserver supports cookies, but there are no built-in methods for accessing them.
Perhaps this can be added to a future release (along with even more cookie support)?

Limitations

I have no way of returning the value of 1 specified cookie name.
For example, if the cookie string looked like:

"name=value; name2=value; name3=value;"

and you wanted the value of name2… still no way to do that).

Webs (ASP)

Add the following functions to the webserver code:

webs.h

extern char_t *websGetCookies(webs_t wp);

webs.c

/******************************************************************************/
/*
 * Get the cookies for this request
 */
 
char_t *websGetCookies(webs_t wp)
{
 a_assert(websValid(wp));
 
 if (wp->cookie == NULL) {
     return T("");
 }
 
 return wp->cookie;
}

main.c

/****************************** Forward Declarations **************************/
static int  getCookie(int eid, webs_t wp, int argc, char_t **argv);
 
websAspDefine(T("getCookie"), getCookie);
 
/******************************************************************************/
/*
 * Test Javascript binding for ASP. This will be invoked when "getCookie" is
 * embedded in an ASP page. See web/cookie.asp for usage. Set browser to
 * "localhost/cookie.asp" to test.
 */
int getCookie(int eid, webs_t wp, int argc, char_t **argv)
{
   char_t* name;
   char_t* str;
 
   int retval = -1;
 
   if (ejArgs(argc, argv, T("%s"), &name) >= 1)
   {
      /* Copy the cookie string so we dont trash it */
      fmtAlloc(&str, BUF_MAX, "%s", websGetCookies(wp));
 
      /* this is the interesting line -- we return our value to the
         interpreter instead of to the browser */
 
      ejSetResult(eid, str);
      bfree(B_L, str);
      retval = 0;
   }
   else
   {
      /*
       * !!! Add error handling support!
       */
   }
   return retval;
}

Example

Here is an example, cookie.asp:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
         "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd>
 
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
 <meta http-equiv="Content-Type" content='text/html; charset="UTF-8"'/>
 <title>Cookie Test Page</title>
 <style type="text/css">
 .clientside
 {
   border: 1px black solid;
   background-color: #eee;
   color: black;
   margin: 5px;
   padding: 4px;
 }
 
 .serverside
 {
   border: 1px black solid;
   background-color: #ccc;
   color: black;
   margin: 5px;
   padding: 4px;
 }
 </style>
 
 <script type="text/javascript">
 <!--
  // Cookie expires in 10 minutes
  expireDate = new Date();
  expireDate.setMinutes( expireDate.getMinutes() + 10 );
 
  function setCookie()
  {
   cookieValue = "";
 
   for ( i = 0; i < document.myform.length; i++)
   {
    if (document.myform[i].type == "text")
    {
     document.cookie = document.myform[i].name + "=" + document.myform[i].value + ";expires=" + 
                       expireDate.toGMTString();
    }
   }
  }
 
  function getCookie( cName )
  {
   if (document.cookie != "")
   {
    thisCookie = document.cookie.split(";");
    for ( i = 0; i < thisCookie.length; i++ )
    {
     cookieName = thisCookie[i].split("=")[0];
 
     if (cookieName == cName)
         return thisCookie[i].split("=")[1];
    }
    return "";
   }
  }
 
  function getCookies()
  {
   if (document.cookie != "")
   {
    thisCookie = document.cookie.split(";");
    for ( i = 0; i < thisCookie.length; i++ )
    {
     cookieName = thisCookie[i].split("=")[0];
     cookieVal = thisCookie[i].split("=")[1];
     document.write(cookieName + ": " + cookieVal + "<br \/>");
     eval("document.myform." + cookieName + ".value = \"" + cookieVal + "\"");
    }
   }
   else
      document.write("No Cookies");
  }
 
  function deleteCookie()
  {
   thisCookie = document.cookie.split(";");
   expireDate = new Date;
   expireDate.setYear( expireDate.getYear() - 1 );
   for ( i = 0; i < thisCookie.length; i++ )
   {
    cookieName = thisCookie[i].split("=")[0];
    document.cookie = cookieName + "=;expires=" + expireDate.toGMTString();
   }
  }
//-->
 </script>
</head>
 
<body>
<h1>  Sample Cookie functions </h1>
<form id="myform" name="myform" action="/goform/login" method="post">
 sessionError: <input type="text" name="sessionError" size="40" /><br />
 TestCookie: <input type="text" name="TestCookie" size="40" /><br />
 <input type="button" onclick="deleteCookie();" value="Delete Cookie"/>&nbsp;
 <input type="button" onclick="setCookie();" value="Update Cookies"/>
</form>
<div class="clientside">
 <h2>Client Side:</h2>
 <script type="text/javascript">
 <!--
  getCookies();
//-->
 </script>
</div>
 
<div class="serverside">
 <h2>Server Side:</h2>
 <%
    // Someday, would like to get back only the value for the cookie name specified
    val = getCookie("sessionError");
    write(val);
 %>
</div>
</body>
</html>

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documentation/goahead/cookies_asp.txt · Last modified: 2005/03/17 10:01 (external edit)