Another post for WordPress admins, building on an earlier WordPress Tip: Bloginfo as a Shortcode

Having a shortcode is great, but why not automate the insertion of the shortcode into the content box? That’s what I’ve done here.

(To use this code, add it to your theme’s functions.php file)

function bsdrelative_content_replace_url($content) {  
  return str_replace(get_bloginfo('url'),'[url]',$content);
}
add_filter('content_save_pre','bsdrelative_content_replace_url');
 
function bsdrelative_url_shortcode($atts, $content = null) {
  return get_bloginfo('url'); 
}
add_shortcode("url", "bsdrelative_url_shortcode");

There’s a reason I’m using a shortcode rather just replacing http://site.com/the/link with /the/link and it’s that the latter assumes that the site is installed at the DocumentRoot of the webserver. Not a safe assumption. Often times, I’m developing a new website for a client under a subfolder such as a http://clientsite.com/staging or http://clientsite.com/dev while the current to-be-replaced site remains at the root level.

I’ve also made this available as a WordPress Plugin

I often need to help move a client’s redesigned website into WordPress at a new webhost. During this process, the client’s domain must remain pointing to the old website so there is no interruption in traffic. Repointing the domain becomes one of the last steps of the process.

WordPress addresses a potential problem here with a Template tag called bloginfo. Inside my theme’s templates, I use bloginfo(‘url’) rather than hardcoding my site’s URL. The actual URL is maintained in the Dashboard under Settings > General > WordPress address (URL). bloginfo(‘template_url’) adds the current theme path to the URL. Often when programming, computing a value gives you more flexibility than hardcoding a value.

Another area where I would like to have this flexibility is inside the actual content of the post. If I upload an image using the Media Uploader, it immediately computes the URL for the image. But I don’t want to have to come back later after the domain has been repointed to edit the URLs in the post. Can’t I have the same delayed computation that bloginfo(‘url’) provides, but inside the content?

Solution 1: Shortcodes for your URLs

Edit your theme’s functions.php

function my_url($atts, $content = null) {
  return get_bloginfo('url'); 
}
add_shortcode("url", "my_url");  
 
function my_template_url($atts, $content = null) {
  return get_bloginfo('template_url'); 
}
add_shortcode("template_url", "my_template_url");  
 
function my_images_url($atts, $content = null) {
  return get_bloginfo('template_url') . '/images'; 
}
add_shortcode("images_url", "my_images_url");

Using this shortcode, I can upload the image, insert the image into the post, and then modify the URL to use the shortcode. I don’t have to return to edit the URL later.

  <img src="[images_url]/chunky.jpg" />

Solution 2: Shortcode for bloginfo itself

I found this solution at Blue Anvil

function bloginfo_shortcode( $atts ) {
    extract(shortcode_atts(array(
        'key' => '',
    ), $atts));
    return get_bloginfo($key);
}
add_shortcode('bloginfo', 'bloginfo_shortcode');

Demo

That was uploaded with the Media Uploader, and here’s the final markup

<a href="[bloginfo key='url']/wp-content/uploads/2010/02/chunky-e1266723693872.jpg">
<img src="[bloginfo key='url']/wp-content/uploads/2010/02/chunky-e1266723693872-225x300.jpg" 
alt="" title="chunky" width="225" height="300" class="alignnone size-medium wp-image-462" /></a>