Can this work on category, archive or taxonomy pages?

Thank you for showing me this. It is very close to what I was looking to do. It seems to work on a category/archive page, but I can’t seem to get it to work on a taxonomy page.

I realize that this isn’t your plugin, but you wouldn’t happen to know off-hand why simply changing this:

foreach(get_categories()

To this:

foreach(get_categories('taxonomy=theslugofthetaxonomy')

Fails to work? Thanks again for your help!

I’ll attempt that and follow up on this issue elsewhere, as it’s no longer relevant to the Next/Previous Page Link Plus plugin. Thank you for your help!

In case anyone comes to this thread in the future, this is what I did to solve my problem.

Here’s the original by alchyhmyth 2011 for reference:

<?php
//alchyhmyth 2011
//transformationpowertools.com/wordpress
//
//a simple next/prev category navigation for category archives
//
foreach(get_categories() as $all_cat) {  $cat_ids[] = $all_cat->term_id; }
  $this_cat = get_query_var('cat');
  $this_cat_position = array_search( $this_cat, $cat_ids ); ?>

<?php $prev_cat_position = $this_cat_position -1;
      if( $prev_cat_position >=0 ) {
      $prev_cat_id = array_slice( $cat_ids, $prev_cat_position, 1 );
    echo '<a href="' . get_category_link($prev_cat_id[0]) . '">« ' . get_category($prev_cat_id[0])->name . '</a>'; } ?>

<?php $next_cat_position = $this_cat_position +1;
      if( $next_cat_position < count($cat_ids) ) {
      $next_cat_id = array_slice( $cat_ids, $next_cat_position, 1 );
echo '<a href="' . get_category_link($next_cat_id[0]) . '">' . get_category($next_cat_id[0])->name . ' »</a>'; } ?>

This works fine on a regular category archive. But, it does not work on a taxonomy archive. I don’t know why. But, if you modify it this way, it works:

<?php
//original by alchyhmyth 2011
//transformationpowertools.com/wordpress
//
//modified for a specificed taxonomy by Puffertle
//
//a simple next/prev navigation for a specificed taxonomy's archives
//

foreach(get_categories('taxonomy=theslugofthetaxonomy') as $all_cat) { $cat_ids[] = $all_cat->term_id; $cat_slug[] = $all_cat->slug; $cat_title[] = $all_cat->cat_name; }

$this_cat = get_queried_object()->term_id;
$this_cat_position = array_search( $this_cat, $cat_ids ); ?>

<?php $prev_cat_position = $this_cat_position -1;
if( $prev_cat_position >=0 ) {

	$prev_cat_id = array_slice( $cat_ids, $prev_cat_position, 1 );
	$prev_cat_slug = array_slice( $cat_slug, $prev_cat_position, 1 );
	$prev_cat_name = array_slice( $cat_title, $prev_cat_position, 1 );
	$my_prev_link_id = $prev_cat_id[0];
	$my_prev_link_slug = $prev_cat_slug[0];
	$my_prev_link_name = $prev_cat_name[0];

	$my_prev_link = get_term_link($my_prev_link_slug, 'theslugofthetaxonomy');
	echo '<a href="' . $my_prev_link . '">« ' . $my_prev_link_name . '</a>';

} ?>

<?php $next_cat_position = $this_cat_position +1;
if( $next_cat_position < count($cat_ids) ) {

	$next_cat_id = array_slice( $cat_ids, $next_cat_position, 1 );
	$next_cat_slug = array_slice( $cat_slug, $next_cat_position, 1 );
	$next_cat_name = array_slice( $cat_title, $next_cat_position, 1 );
	$my_next_link_id = $next_cat_id[0];
	$my_next_link_slug = $next_cat_slug[0];
	$my_next_link_name = $next_cat_name[0];

	$my_next_link = get_term_link($my_next_link_slug, 'theslugofthetaxonomy');
	echo '<a href="' . $my_next_link . '">' . $my_next_link_name . ' »</a>'; 

} ?>

Just make sure to change the three (3) instances of theslugofthetaxonomy to the actual slug of the taxonomy you’re wanting to navigate through.

Things I noticed:

get_query_var('cat')

Wasn’t working on a taxonomy archive, but this did:

get_queried_object()->term_id

Also, when dealing with a taxonomy, get_category_link and get_category were not working. Instead, get_term_link had to be used. Also, the taxonomy ID was not sufficient for what had to be done. The slug and name had to be added:

$cat_ids[] = $all_cat->term_id; $cat_slug[] = $all_cat->slug; $cat_title[] = $all_cat->cat_name;

So they could be called here:

$prev_cat_id = array_slice( $cat_ids, $prev_cat_position, 1 );
	$prev_cat_slug = array_slice( $cat_slug, $prev_cat_position, 1 );
	$prev_cat_name = array_slice( $cat_title, $prev_cat_position, 1 );
	$my_prev_link_id = $prev_cat_id[0];
	$my_prev_link_slug = $prev_cat_slug[0];
	$my_prev_link_name = $prev_cat_name[0];

Your advice about the var_dump was helpful, as it let me see what values were available, though upon a first glance the output didn’t look any different from a category archive. I think the problem may have had something to do with how WordPress treats taxonomies differently from a category.

I am not very proficient with PHP, so if you see a better way to do this than what I’ve shown please let me know.