<?php
    
    // The two following lines belong into the theme's functions.php or wherever scripts are
    // embedded for Plugins or Widgets. "portfolio-page.js" is the script I want to make
    // Ajax calls from.
    
    // This is the wordpress way of embedding scripts into a page.
    wp_enqueue_script('portfolio-page', get_template_directory_uri() . '/js/portfolio-page.js', array('jquery'), false, false);
    
    // This means: "Allow portfolio-page to call stuff with Ajax."
    wp_localize_script('portfolio-page', 'ajaxAdmin', array( 'ajaxurl' => admin_url( 'admin-ajax.php' )));


    
    // These two lines belong into functions.php as well. They map the Ajax calls to the respective
    // Php methods. It's important that the parameters match exactly, e.g. here "tne_load_post_content"
    // (yes, including the wp_ stuff).
    add_action( 'wp_ajax_tnet_load_post_content', 'tnet_load_post_content' );
    add_action( 'wp_ajax_nopriv_tnet_load_post_content', 'tnet_load_post_content' );

   
   
    // This is the actual method that is called from the Javascript.
    function tnet_load_post_content()
    {
        $id = $_POST['pageId']; // Parameters sent by Javascript can be accessed like this.
        
        // Here it is checked, if the current page is one with a Siteorigin layout.
        $meta = get_post_meta( $id, 'panels_data', true );
        if( class_exists( 'SiteOrigin_Panels' ) && $meta )
        {
            // Yes: Use Siteorigin magic to get the layout.
            $renderer = SiteOrigin_Panels::renderer();
            $content = $renderer->render( $id );
        }
        else
        {
            // No: Get the layout the standard Wordpress way.
            $content = apply_filters( 'the_content', get_page($id)->post_content );
        }
        
        // Hand the layout back to the caller.
        echo $content;
        
        // With this wordpress will at a "0" in the response.
        die(); 
    }
?>