Slugs PHP Categories and substr functions that I don't understand.

Hi Folks,

I’m attempting to create a new category template in someone else’s code.
I’m unfamiliar with how the original programmer is using slugs and categories in wordpress.
Could someone please explain how this code opens a “tour” in a specific single template:

<?php // check to see if this is a tour menu page ?>
<?php if(is_tour(the_slug(false,'solo'))){
	include('single-tour-template.php');
} else { ?>
<?php get_header(); ?>

Its pretty clear that the is_tour function is doing something to decide that the tour page is the current page and it decides to use the “single-tour-template.php” I just can’t figure out how to add a new template to this function without breaking all the other tours on the site. I’d be adding in say: ‘single-tour-template-new.php’.

Here is the custom Function : is_tour

function the_slug($echo = true, $slugtype = 'solo') {

	$preslug = $_SERVER['REQUEST_URI'];
	$fullSlug = substr($preslug,1,strlen($preslug));
	substr_count($preslug,"/",1) > 0 ? $slug_length = strpos($preslug,"/",1) : $slug_length = strlen($preslug);
	$rootSlug = substr($preslug,1,$slug_length-1);
	$slug = substr($preslug, strrpos($preslug,"/")+1); 

	switch ($slugtype) {
		case 'solo':
			$out = $slug;
			break;
		case 'root':
			$out = $rootSlug;
			break;
		case 'full':
			$out = $fullSlug;
			break;
	}

	if ( $echo ){
		echo $out;
	} else {
		return $out;
	}
}

as well as this I believe:

function is_tour($slug){
	global $wpdb;
	$is_tour = false;
	$post_id = $wpdb->get_var("SELECT ID FROM $wpdb->posts WHERE post_name = '$slug'");
	$cats = get_the_category($post_id);
	foreach($cats as $cat){
		if($cat->slug == 'tour-itinerary'){
			$is_tour = true;
			break;
		}
	}

	return $is_tour;
}

I tried a conditional statement that would make a server request which would pull in the current URL and if it was on the specific page I put in the code then it would use the new template. It appears that the PHP code only reads the IS_tour function and doesn’t get to the elseif part of the code.

<?php if(is_tour(the_slug(false,'solo'))){
	include('single-tour-template.php');
} elseif ($_SERVER['REQUEST_URI'] == '/destinations/quebec-city/3-day-french-trips-chartered-by-motorcoach-springsummer'){
	include('single-tour-template-new.php');
}
	else { ?>

Is there someway I can do both? An if statement that will look at both and choose the URL option instead of the ‘solo’ option?

If anyone could help me with even a basic understand of what the is_tour function is I’d greatly appreciate it!

I’ve been stuck on this for a couple days now.

Link to the Destination page with the tours at the bottom:
https://visitcanada.com/destinations/quebec-city
Look at the blue links at the bottom the tour I’m changing is the first one down.

Link to tour I’m building a new template for:
https://visitcanada.com/destinations/quebec-city/3-day-french-trips-chartered-by-motorcoach-springsummer

Please let me know if you need anymore details.

Thank you again,
D