How to I attach the node ID to my web link? - php

Question

I have built a website where the user plays a simple guess the animal game with the system. The database that the script connects to is a one table binary tree, with each row having a node ID. I need to print the URL on screen that contains the current stage of the game so that if it were copied and pasted it would take another user to the same point. How do I do this?
$query = "SELECT `message`, `parentID`,`answerYesID`, `answerNoID`, `nodeID` FROM `creature`";
$where = "";
if(isset($_POST['answer'])){
$_SESSION['node'] = $_POST['answer'];}
elseif (isset($_SESSION['node'])){ $where = "WHERE `nodeID` = '{$_SESSION['node']}'";}
else { $where = "WHERE `parentID` IS NULL";}
?>
<?php
if (isset($_POST['reset'])){
$where = "WHERE `parentID` IS NULL";
$_SESSION['node'] = 1;
echo $_SESSION['node'];
}
if (isset($_POST['submit']) && (isset ($_POST['answer']))){
$where = "WHERE `nodeID` = '{$_POST['answer']}'";
}elseif (isset($_POST['submit']) && (!isset ($_POST['answer']))){
$where = "WHERE `nodeID` = '{$_SESSION['node']}'";
}
echo'<div class="form">';
$result = mysqli_query($dbconn, $query.$where);
$row = mysqli_fetch_assoc($result);
echo "<p class = \"answer\">";
echo$row['message'];
echo "</p>";
?>
<form action="assignment.php" method="POST">
<input type="radio" name="answer" value="<?php echo $row['answerYesID'];?>">Yes
<input type="radio" name="answer" value="<?php echo $row['answerNoID'];?>">No
<input type="submit" name="submit" value="submit" class = "submit">
<input type='submit' name='reset' value='reset' class = "reset">
click here...
</form>
</div>
<div class = "speech">
<span class= "welcome" ><h1>Welcome!</h1></span>
<p>My name is Barry and I'm the game keeper.<br>
This is the Creatures Expert Game. Answer <br>
the first question to begin. Let's see if I can <br>guess what creature you are thinking of!<br>
<br> Hit the reset button to restart at anytime.</p>
<a><img src="speech.png"></a>
</div>
<div class ="sparky">
<a><img src="sparkydog.png"></a>
</div>
<div class ="sign">
<a><img src="sign.png"></a>
</div>
</body>
</html>
the page is viewable at s573022.neongrit.net/assignment

Answer 1

Since you are using SESSION, instead of href="assignment.php" you can echo:
click here...
But the problem with your existing code is that you are setting $_SESSION['node'] only if you detect a $_POST['answer'] which is impossible if you do not submit a form.
Therefore, you need to first check if you have the nodeId set in the url like so at the very beginning of the file:
if (isset($_GET['nodeId']) && $_GET['nodeId'] != '') {
$_SESSION['node'] = $_GET['nodeId'];
}
else { //do whatever you do now to get the answer }