Creating Dynamic, Session-Aware Links

 $name = urlencode(session_name()); $id = urlencode(session_id()); echo "<a href=\"page.php?$name=$id\">dynamic   link</a>"; 

Using session.use_trans_sid to automatically update all links to contain the session ID, if required, is a good thing; however, it does not work if those links are dynamically generated by PHP. However, PHP offers two functions that provide all information that is needed:

• session_name() returns the name of the session.

• session_id() returns the current session's ID.

Therefore, the preceding code creates a dynamic link that contains this information, enabling the programmer to make dynamic links session-aware.

One potential output of this code is the following:

 <a href="page.php?PHPSESSID=    5b25b64843fad0d1afb4286cfe0ed448">dynamic    link</a> 

TIP

When you use an HTML form, PHP automatically appends the session ID to the action attribute of the form. However, if you want to use dynamic forms, you can add a hidden form field to the form, containing the session information:

 <?php   $name = htmlspecialchars(session_name());   $id = htmlspecialchars(session_id());   echo "<input type=\"hidden\" name=\"$name\"     value=\"$id\" />"; ?>