PHP variables with JSON data

[ohno]

I wasn't sure if this should be in the JS/AJAX section or PHP,as the JS part seems OK I guess here! I have this at the very top of my script : -

// Get the data from the AJAX request
	$searchQuery = isset($_POST['searchQuery']) ? $_POST['searchQuery'] : '';
	$sessionid = isset($_POST['sessionid']) ? $_POST['sessionid'] : '';
	// Declare as global variables
	// tried, no change // global $searchQuery, $sessionid;
	
	// Log the data to a text file
	$logData = "Received data from JavaScript:\n";
	$logData .= "Search Query: " . $searchQuery . "\n";
	$logData .= "Session ID: " . $sessionid . "\n\n";

	$logFilePath = __DIR__ . '/log.txt';
	file_put_contents($logFilePath, $logData, FILE_APPEND);

This is working fine as I have checked the log file, so the payload is received OK. I then have this code lower down in my script :

// Check if $searchQuery and $sessionid are not empty			
			if (!empty($searchQuery) && !empty($sessionid)) {
				// Check if the sessionid from the database matches the sessionid from the AJAX payload
				if ($data['sessionid'] == $sessionid) {					
					echo '<td class="center">***** ' . $searchQuery . ' *****</td>';
				} else {
					echo '<td class="center">No search query available</td>';
				}
			} else {
				echo '<td class="center">Missing search query or session ID</td>';
			}
			// End

With the above I get nothing, If I hard code a `sessionid` and a search term it appears in my HTML table for the correct user. Ie, with this it "works" :

 

			$searchQuery = 'This is where the data should appear!!';
			$sessionid = '28if81v4amdsl7qlh5f5ktvc1r';

			// Check if $searchQuery and $sessionid are not empty
			
			if (!empty($searchQuery) && !empty($sessionid)) {
				// Check if the sessionid from the database matches the sessionid from the AJAX payload
				if ($data['sessionid'] == $sessionid) {					
					echo '<td class="center">***** ' . $searchQuery . ' *****</td>';
				} else {
					echo '<td class="center">No search query available</td>';
				}
			} else {
				echo '<td class="center">Missing search query or session ID</td>';
			}
			// End

Why can I not use the variables set at the top of my page? Or, how can I fix this?! Thanks for any help

Edited October 17, 2023 by ohno

[requinix]

1 hour ago, ohno said:

I then have this code lower down in my script :

But what's everything in between?

Or rather, what's the whole script? Because there's something important here that isn't shown in what you've posted - if statements, function calls, reused variables...

Also, partly for good measure and partly because there's a rather high likelihood that doing so will help you discover the problem: have you verified that your error reporting/logging settings are appropriate, and then checked for error messages?