Create custom page templates with plugins?

 Create custom page templates with plugins?

 

// Publication page template -----------------------

//Add our custom template to the admin's templates dropdown
add_filter( 'theme_page_templates', 'pluginname_template_as_option_publications', 10, 3 );
function pluginname_template_as_option_publications( $page_templates, $theme, $post ){

    $page_templates['template-publication.php'] = 'Publications new shahinn';

    return $page_templates;

}

//When our custom template has been chosen then display it for the page
add_filter( 'template_include', 'pluginname_load_template_publications', 99 );
function pluginname_load_template_publications( $template ) {

    global $post;
    $custom_template_slug   = 'template-publication.php';
    $page_template_slug     = get_page_template_slug( $post->ID );

    if( $page_template_slug == $custom_template_slug ){
        return plugin_dir_path( __FILE__ ) . $custom_template_slug;
    }

    return $template;

}
//end page template-------------------------