<?php
/*
Plugin Name: Site Link Shortcode
Author: James FL
Tags: site url, relative links, move blog

*/

/**
 * Adds shortcode to use for site links
 * Lets widgets use shortcode
 * @since Twenty Ten 1.0
 */

	function mySiteUrl() {
	    return get_option('home');
	}
	add_shortcode('site_url', 'mySiteUrl');
	add_filter('widget_text', 'do_shortcode');

	function myUploadsUrl() {
		$upload_dir = wp_upload_dir();
        return $upload_dir['baseurl'];
	}
	add_shortcode('uploads_url', 'myUploadsUrl');

	function rewrite_links_automatically($content) {
	   $content = str_replace(myUploadsUrl(), '[uploads_url]', $content);
       $content = str_replace(mySiteUrl(), '[site_url]', $content);
	   return $content;
	}

	function reverse_shortcode_for_editor($content) {
	   //replace shortcode for uploads (images, media, etc. so it displays in the editor)
	   $content = str_replace('[uploads_url]',myUploadsUrl() , $content);
	   $content = str_replace('[site_url]', mySiteUrl(), $content);
	   return $content;
	}

	//variable to set to automatically rewrite links
	$auto_link_rewrite = true;
	if($auto_link_rewrite) {
		add_filter('content_save_pre', 'rewrite_links_automatically');
		add_filter('the_editor_content', 'reverse_shortcode_for_editor');
	}

?>