[WordPress] Working with Custom Rewrite Rules and Page Templates in WordPress

00-read-query.php

<?php 

$query = $this->query->query([
    'post_type' => 'page',
    'meta_key' => '_wp_page_template',
    'meta_value' => ['template-alpha.php', 'template-beta.php'],
]);

if (!$query) {
    return;
}

// More to come...

001-store-templated-pages.php

<?php

foreach ($query as $post) {
    $slug = get_page_template_slug($post->ID);

    if ('template-alpha.php' === $slug) {
        $this->alphaPages[] = $post;
    }

    if ('template-find-a-camp.php' === $slug) {
        $this->betaPages[] = $post;
    }
}

02-country-state-rules.php

<?php

add_rewrite_tag('%country%', '([^&]+)');
add_rewrite_tag('%state%', '([^&]+)');

foreach ($this->alphaPages as $post) {
    add_rewrite_rule(
        '^'.$post->post_name.'/([^/]*)/([^/]*)/?',
        'index.php?page_id='.$post->ID.'&country=$matches[1]&state=$matches[2]',
        'top'
    );

    add_rewrite_rule(
        '^'.$post->post_name.'/([^/]*)/?',
        'index.php?page_id='.$post->ID.'&country=$matches[1]',
        'top'
    );
}

03-acme-id-rules.php

<?php

add_rewrite_tag('%acme-id%', '([^&]+)');

foreach ($this->betaPages as $post) {
    add_rewrite_rule(
        '^(.*)?/([A-Za-z0-9-]+-)(\d+)/?',
        'index.php?page_id='.$post->ID.'&acme-id=$matches[3]',
        'top'
    );
}

04-final-functions.php

<?php

public function addRewriteRules()
{
    $query = $this->query->query([
        'post_type' => 'page',
        'meta_key' => '_wp_page_template',
        'meta_value' => ['template-alpha.php', 'template-beta.php'],
    ]);

    if (!$query) {
        return;
    }

    $this->setPageTypes($query);
    $this->setAlphaRewriteRules();
    $this->setBetaRewriteRules();
}

private function setPageTypes($query)
{
    foreach ($query as $post) {
        $slug = get_page_template_slug($post->ID);

        if ('template-alpha.php' === $slug) {
            $this->alphaPages[] = $post;
        }

        if ('template-find-a-camp.php' === $slug) {
            $this->betaPages[] = $post;
        }
    }
}

private function setAlphaRewriteRules()
{
    add_rewrite_tag('%country%', '([^&]+)');
    add_rewrite_tag('%state%', '([^&]+)');

    foreach ($this->alphaRules as $post) {
        add_rewrite_rule(
            '^'.$post->post_name.'/([^/]*)/([^/]*)/?',
            'index.php?page_id='.$post->ID.'&country=$matches[1]&state=$matches[2]',
            'top'
        );

        add_rewrite_rule(
            '^'.$post->post_name.'/([^/]*)/?',
            'index.php?page_id='.$post->ID.'&country=$matches[1]',
            'top'
        );
    }
}

private function setBetaRewriteRules()
{
    add_rewrite_tag('%acme-id%', '([^&]+)');

    foreach ($this->betaPages as $post) {
        add_rewrite_rule(
            '^(.*)?/([A-Za-z0-9-]+-)(\d+)/?',
            'index.php?page_id='.$post->ID.'&acme-id=$matches[3]',
            'top'
        );
    }
}