If you post helpful information on your blog chances are some of your early posts are now outdated as technologies have changed over the years. Let’s take a look at how we can add a mix of PHP tags to our WordPress themes to automatically add a small disclaimer or warning message to posts over X years old.
The little snippets of code we’re going to add to our theme will allow us to display a message above our post content, but only on posts over a number of years old. We might only want to display this message on certain types of posts, in my case it’s only my tutorials that have become outdated, so we’ll also add a category filter to target only old posts from a particular section of the blog.
<?php
$post_age = date('Y') - get_the_time('Y');
if($post_age > 2 && in_category('4') ) { ?>
<div>
<p><strong>This post was originally published in <?php the_time('Y'); ?></strong><br />
The tips and techniques explained may be outdated.</p>
</div>
<?php } ?>
I had to do a little Google researching to actually figure this out. I stumbled over Horacio Bella’s Forrst post that provides the basic syntax, I then did a little modification to suit my own requirements.
The first line of code takes today’s year and minuses the year the post was published, which gives the post’s age in the $post_age variable. The script then checks if the post age is over 2 years old and is in category ID 4. You could change this filter using many of the WordPress Conditional Tags.
A line of simple HTML fleshes out a message to the user, explaining that the post is a few years old and therefore the content may be outdated. We can use the WordPress <?php the_time('Y'); ?> tag to automatically enter the year the post was published.
Paste this code into your single.php template file above the <?php the_content(); ?> tag.
The CSS styling
Once the code is in place in the template file and the unformatted message is appearing on the correct posts, it can then be styled up with CSS.
.old-post {
margin: 0 0 20px 0; padding: 15px 20px;
background: #e9e9eb url(images/grey-bg.png);
}
.old-post p {
background: url(images/warning.png) left no-repeat; padding: 0 0 0 65px;
color: #717171;
}
The old-post div is styled up with a textured grey background and plenty of padding around the edges. A warning icon is then added as a CSS background image on the paragraph element and the text indented with some left padding.
Source: http://line25.com/tutorials/how-to-display-a-message-on-old-wordpress-posts
