In terms of keeping design and content together. I’m not so fussed when it comes to my blog (probably ’cause it’s a personal blog that will change as I do), but if I were I would go with a conditional stylesheet. A few times when I’ve changed infrastructure I’ve actually done a search and replace in my database to make class names etc match up with the new ones, rather than continue to maintain deprecated CSS. It was pretty quick and I find it reassuring that my database is up to date as well.

(Editor’s Note: Bitch.)

You can find it under old wordpress designs on my site.

I quite like the subdomain idea really. With that system you could replace all of the links to a certain age of content with a subdomain’d link, offering a link to your most recent design as the same url without the subdomain attached.

// Define the cutoff date (Format: YYYYMMDD)
$cutoff_date = 20070517;

if ( have_posts() ) :
while ( have_posts() ) : the_post();
$old = (get_the_time(‘Ymd’) > $cutoff_date) ? TRUE : FALSE;
endwhile;
endif;

if ($old === TRUE)
{
include(TEMPLATEPATH . ‘old_design.php’);
// Where old_design.php is the complete template for a single old design page
}
else
{
// Put your new design for single pages here
}

This obviously adds new queries into the process which a plugin might avoid but it’s quick and dirty and, on quick testing, appears to work. You could also refine the loop to be a single query.

Hope it helps.

Seems like the easiest approch is to use templates..
http://codex.wordpress.org/Tag_Templates
And tag all old post with “old” or something like that..

As I assume keeping the old design will be solely for individual pages you could set up a conditional in your single.php where before the cut-off date you load say old_design.php. In that file you then have the full page code (ie no separation of headers, footers and sidebars) and also have it calling the old_design.css.

It’d be quicker to get up and running than all the hassle of creating a plugin given that you have template sitting ready to go & just need to do a little copy & pasting exercise + a single php conditional.

Problems might be introduced through the central options set in the admin panel (settings & widgets included). Not a huge problem depending on how different the design will be. Also, you could quickly get round these by hard coding most of them into the theme files anyway.

I think a lot of this decision comes down to “how much do you like/hate your current design”? In a lot of redesigns, the designer has grown to hate the old design (or he’s working with someone else’s design so he already hates it). If this was the case for me, I might feel differently. But I actually like my current design still. Its shine has dulled a bit, but I can’t say it bothers me at all. The redesign would be more about adding functionality and better separating out different types of content. It’s driven a lot by the fact that these days I like to publish a lot of things that aren’t really design or code related and I want a site that lets me publish all sorts of content without subjecting everybody to it who may only be interested in the design/code stuff.

If a new reader landed on your homepage and saw version #3 of your site, they will sub-consciously indexed the branding to your site. Now let us say that they click a link in your Recent Entries section and the page that is served is styled as was in version #1 or version #2 of your site. This will be very misleading to a new reader, as there is inconsistency with your brand or your online identity.

. Site design is an all or nothing thing. I would advocate looking at your current content and make design decisions early based on that. Of course this is a harder approach

Very interesting.

I think I’m going to either contact Nicolas and see if he wants to add that functionality in officially, or maybe I’ll just hack it in myself and send it to him. Thanks!

It should be VERY simple to change.

Just replace
if(current_user_can(get_option(‘nkthemeswitch_level’))) {
With a check for postdate..