Wordpress Taxonomy listing - Pagination - php

Question

I found this excellent function to display all the posts listed under a specific custom taxonomy. It works great. Found here http://gilbert.pellegrom.me/wordpress-list-posts-by-taxonomy I tried a number of ideas, however unsuccessful, to try and paginate the returned data. I either get no data or it continues to display the entire list. Some of my taxonomies have over 10K posts associated. So pagination would seem logical.
What I want to do is; have the information that gets returned create pages of 'n' number of posts and make links for the other pages (1,2,...4,5 etc). Any help is greatly appreciated.
I tossed this in my functions file;
function list_posts_by_taxonomy( $post_type, $taxonomy, $get_terms_args = array(),
$wp_query_args = array() ){
$tax_terms = get_terms( $taxonomy, $get_terms_args );
if( $tax_terms ){
foreach( $tax_terms as $tax_term ){
$query_args = array(
'post_type' => $post_type,
"$taxonomy" => $tax_term->slug,
'post_status' => 'publish',
'posts_per_page' => -1,
'ignore_sticky_posts' => true
);
$query_args = wp_parse_args( $wp_query_args, $query_args );
$my_query = new WP_Query( $query_args );
if( $my_query->have_posts() ) { ?>
<h2 id="<?php echo $tax_term->slug; ?>" class="title">
<?php echo $tax_term->name; ?></h2>
<ul>
<?php while ($my_query->have_posts()) : $my_query->the_post(); ?>
<li><a href="<?php the_permalink() ?>" rel="bookmark"
title="Permanent Link to <?php the_title_attribute(); ?>">
<?php the_title(); ?></a></li>
<?php endwhile; ?>
</ul>
<?php
}
wp_reset_query();
}
}
}
?>
And this code goes in the template, stuff whatever 'taxonomy' name and it displays the data. Another questions I was not sure about, if the pagination should go in the function or the template.
<div class="my_class">
<?php
list_posts_by_taxonomy( 'my_posttype', 'taxo_mytaxo' );
?>
</div>
Thank you everyone!

Answer 1

In order to have pagination with your query first of all you have to use the paged parameter.
To get some extra info check the wordpress codex for Pagination
Usually you get the pagination variable like this:
<?php $paged = (get_query_var('paged')) ? get_query_var('paged') : 1; ?>
Then you pass it to the query by including it in the query arguments for your code:
$query_args = array(
'post_type' => $post_type,
"$taxonomy" => $tax_term->slug,
'post_status' => 'publish',
'posts_per_page' => -1,
'ignore_sticky_posts' => true
'paged' => $paged //I've added it here
);
Then you'll have to build the pagination links something like(this will be done inside the loop):
<!-- Add the pagination functions here. -->
<div class="nav-previous alignleft"><?php next_posts_link( 'Older posts' ); ?></div>
<div class="nav-next alignright"><?php previous_posts_link( 'Newer posts' ); ?></div>