timeline-page-template.php

<?php

add_filter('theme_page_templates', 'timeline_add_page_template_to_dropdown');
add_filter('template_include', 'timeline_change_page_template');
add_action('wp_enqueue_scripts', 'timeline_remove_style' );
 
/**
 * Add page templates.
 *
 * @param  array  $templates  The list of page templates
 *
 * @return array  $templates  The modified list of page templates
 */
function timeline_add_page_template_to_dropdown($templates)
{
    $templates[plugin_dir_path(__FILE__) . 'template/template-timeline.php'] = __('timeline template', 'text-domain');
 
    return $templates;
}
 
/**
 * Change the page template to the selected template on the dropdown
 * 
 * @param $template
 *
 * @return mixed
 */
function timeline_change_page_template($template)
{
    if (is_page()) {
        $meta = get_post_meta(get_the_ID());
 
        if (!empty($meta['_wp_page_template'][0]) && $meta['_wp_page_template'][0] != $template) {
            $template = $meta['_wp_page_template'][0];
        }
    }
 
    return $template;
}
 
function timeline_remove_style()
{
    // Change this "my-page" with your page slug
    if (is_page('my-page')) {
        $theme = wp_get_theme();
 
        $parent_style = $theme->stylesheet . '-style'; 
 
        wp_dequeue_style($parent_style);
        wp_deregister_style($parent_style);
        wp_deregister_style($parent_style . '-css');
    }
}