why is this script not working on my site

Question

I found a script so I can take care that on some months I can change the number of post at a page.

So I implment this script at this way : http://pastebin.com/Nbqy0KBU

But still all articles are displayed as you can see here : http://test.tamarawobben.nl/2005/04

Anyone a idea why and how to solve this ?

Roelof

Edit 1 :

What I want to achieve is this in pseudo code.

When the year is 2005 and the month april(04) and we are on the first page of that month then 1 article must be displayed. if not then the standard number of articles must be displayed.

Answer 1

Consider this option of achieving what you seem to be requiring:

function wpse31701_filter_query() {
    global $wp_query;
    // Check year and month
    if ( $wp_query->get( 'year' ) == 2005 and $wp_query->get( 'monthnum' ) == 5 )
        // Check page number to apply offset
        if ( $wp_query->get( 'paged') > 1 ) $wp_query->set( 'offset', 1 );
        else $wp_query->set( 'posts_per_page', 1);
}
add_action( 'pre_get_posts', 'wpse31701_filter_query' );

Here we alter the query as soon as $the_query is ready to get the posts, to modify the posts_per_page to 1 if paged is 1, and apply and offset of 1 post if paged is > 1.

The important thing is to apply offset and posts_per_page; the rest is purely conditional so apply to taste.

Answer 2

is_category(); is checking if you're on a category archive or not. So, is_category('1perpage'); will only return true when you're on http://test.tamarawobben.nl/category/1perpage/

Answer 3

It doesn't look like there are any template tags to achieve what you want, so you're stuck comparing the query string (try get_query_var(query_vars)) to 200504

From the $WP_Query object: ... [query_vars] => Array ( [m] => 201110 ...

If it's a match, you have a multitude of options... I might try an if/then bracket... psuedo code:

 if ($queryvar == '200504' && $paged == 1):
    $singlepost = get_post(...);
    // write display code for your singleton post.
 else:
    query_posts($query_string.'&offset=1');
    //run through the normal loop code here
 endif;

This is still likely to mess with paging, which is the sticky wicket here... I'm sure someone else can come up with a better answer, but maybe that'll get you started.