How can i call an article from each category and still paginate properly?

Question

I want to have my front page, with three columns, each assigned to a different category. Ideally I would like to query to fetch one post, per column, per page where possible, leaving the column empty if not.

My current loop simply gets 3 posts at a time. It is reasonable to assume that the 3 will not be one of each category.

Here is the loop:

<?php

            global $query_string;
            parse_str( $query_string, $my_query_array );
            $paged = ( isset( $my_query_array['paged'] ) && !empty( $my_query_array['paged'] ) ) ? $my_query_array['paged'] : 1;
            query_posts('post_type=post&posts_per_page=3&paged='.$paged);


            if ( have_posts() ) : while ( have_posts() ) : the_post();

            $category = choose_one_category(get_the_category());

            switch ($category){
                case "Festival News":
                    $left[] = $post;
                    break;
                case "Industry News":
                    $centre[] = $post;
                    break;
                case "Other":
                    $right[] = $post;
                    break;
            }


            endwhile; 
            ?>
            <div class="custom-pagination">

            <div ><?php previous_posts_link('&laquo; Previous') ?></div>

            <div ><?php next_posts_link('Next &raquo;') ?></div>
            </div>
            <?php endif;



            ?>

Answer 1

My recommendation would be to use a separate query for each column - getting 1 post per category - and pass the global $paged variable into each. This should exhibit the behavior you described in your question (at least it does on my site).

My setup

I have a top section that displays the 5 most recent posts from the "featured" category if you're on page 1 only. Then I have a sidebar that displays the first page of posts from each of 3 primary categories, each using their own query with posts_per_page=1. Then I have the main section that displays all posts normally with 5 posts on each page.

The first page returns my featured posts in a slider, the regular post section below it, and the first post from my three core categories in the sidebar. Page 2 hides the "featured" slider, returns the next 5 posts overall in the main section and the second post in each of my core categories. Page 3 and beyond do the same thing.

So what you'll need is not one loop over 3 categories, but 3 loops each over a single category and each using the global $paged variable.