WordPress Pagination Won't Switch Pages - php

Question

I have been searching for a solution to this issue for over a week and I haven't been able to find anybody else with the same trouble.
I am working on a custom WP theme that somebody else built. There is a single-page template that I need to implement paging on for one of the secondary loops. I have been attempting to use the built-in paginate_links() function, as well as other methods. The pagination links show up, but when I click on a pagination link it doesn't go to that page in the pagination. Instead the original page is reloaded (i.e. instead of going to thewebsite.com/my-page/page/2/, it reloads thewebsite.com/my-page/).
The previous dev used this filter in functions.php to load the correct template:
add_filter('single_template', create_function('$t', 'foreach( (array) get_the_category() as $cat ) { if ( file_exists(TEMPLATEPATH . "/single-{$cat->slug}.php") ) return TEMPLATEPATH . "/single-{$cat->slug}.php"; } return $t;' ));
And here is my template file:
<?php
/**
* Template Name: Project Template
*/
get_header('news'); ?>
<article role="main" class="projectpage">
<div class="container">
<section class="pagecontent">
<?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>
<section class="overview">
<h1><?php the_title(); ?></h1>
<div>
<?php the_content(); ?>
</div>
<div>
<?php if(get_post_meta($post->ID, 'pagelink', true)): ?>
Read the Overview
<?php endif; ?>
</div>
</div><!--end row-->
</section><!--end overview-->
<?php endwhile ?>
<?php wp_reset_postdata() ?>
<? endif ?>
<section class="related">
<div>
<h1> Related Resources </h1>
<h2> Explore our library of articles and resources </h2>
</div>
<div class="row">
<div class="col-lg-3 col-md-3 col-sm-3 col-xs-3 relatedlinks">
<section class="projectcategories">
<h3> Categories </h3>
<ul>
<?php wp_list_categories( array(
'orderby' => 'id',
'show_count' => true,
'use_desc_for_title' => false,
'child_of' => 93,
'title_li' => ' '
) ); ?>
</ul>
</section>
<section class="project-search" role="search">
<form method="get" action="<?php echo esc_url( home_url( '/' ) ); ?>">
<input type="hidden" name="cat" id="cat" value="93" />
<input type="text" size="16" name="s" placeholder="search keywords" class="search-box" />
<input type="submit" value="Go" class="go"/>
</form>
</section>
<section class="otherprojects">
<h3> Other Projects </h3>
<?php
$args = array(
'category__in' => 91,
'post__not_in' => array( $post->ID )
);
// the query
$query = new WP_Query( $args );
$temp_query = $wp_query;
$wp_query = NULL;
$wp_query = $query;
// The Loop
if ( $query->have_posts() ) : while ( $query->have_posts() ) : $query->the_post(); ?>
<?php the_title(); ?>
<? endwhile ;
/* Restore original Post Data */
wp_reset_postdata();
endif;
$wp_query = NULL;
$wp_query = $temp_query;
?>
</section>
</div><!--end col 1-->
<div class="col-lg-9 col-md-9 col-sm-9 col-xs-9">
<section class="articles">
<?php
// THIS IS THE SECTION WHERE I NEED THE PAGINATION
$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
$args = [
'posts_per_page' => 3,
'paged' => $paged,
'post_type' => 'post',
'order' => 'DESC',
'post__not_in' => array( $post->ID ),
'tax_query' => [
[
'taxonomy' => 'category',
'field' => 'term_id',
'terms' => '93',
],
],
];
$custom_query = new WP_Query( $args );
$temp_query = $wp_query;
$wp_query = NULL;
$wp_query = $custom_query;
if ( $custom_query->have_posts() ) {
while ( $custom_query->have_posts() ) {
$custom_query->the_post(); ?>
<div class="row">
<div class="col-md-2 col-sm-2 col-xs-2 divider">
<p class="date"><?php the_time('M j') ?></p>
</div><!--end col-->
<div class="col-md-4 col-sm-4 col-xs-4">
<div class="articleimg">
<?php if ( has_post_thumbnail()) {?>
<?php the_post_thumbnail('blog-thumb'); ?>
<?php } ?>
</div><!--end blogimg-->
</div><!--end col-->
<div class="col-md-6 col-sm-6 col-xs-6">
<div class="blogcontent">
<h3><?php the_title();?></h3>
<p><?php the_excerpt(); ?></p>
// read more
</div><!--end blogcontent-->
</div><!--end col-->
</div><!--end row-->
<?php }
}
echo paginate_links(array(
'total' => $wp_query->max_num_pages
));
$wp_query = NULL;
$wp_query = $temp_query;
wp_reset_postdata(); ?>
</section><!--end articles-->
</div><!--end col 2-->
</div> <!--end row-->
</section><!--end related-->
<!-- ANNOUNCEMENTS -->
<!--ANNOUNCEMENT SECTION -->
<!-- dynamic content --filters posts by category and only shows 'member' posts with a limit of six posts being
displayed-->
<section id="announcement-front" class="clearfix">
<div class="container">
<div>
<?php $query = new WP_Query('posts_per_page=1&category_name=advertisement');
if ($query->have_posts()) :
while ($query->have_posts()) : $query->the_post(); ?>
<a href="<?php the_permalink()?>" <?php the_content();?> </a>
<?php endwhile ?>
<? endif ?>
<?php wp_reset_postdata() ?>
</div><!--end row-->
</div><!--container-->
</section><!--end announcement-->
</section> <!--end page content -->
</div><!--end container-->
</article>
<?php get_footer(); ?>
I realize there is a whole galaxy of WordPress pagination tutorials and threads out there, but I haven't been able to find one yet that solves this particular problem.

Answer 1

I think your code should mostly work. You don't need to worry about all the saving and switching of $wp_query though - have you tried this simpler snippet? It worked ok in my environment (though I had to modify the query args slightly to get it to return any results).
If that's not working can you post the HTML it generates?
<section class="articles">
<?php
// THIS IS THE SECTION WHERE I NEED THE PAGINATION
$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
$args = [
'posts_per_page' => 3,
'paged' => $paged,
'post_type' => 'post',
'order' => 'DESC',
'post__not_in' => array( $post->ID ),
'tax_query' => [
[
'taxonomy' => 'category',
'field' => 'term_id',
'terms' => '93',
],
],
];
$custom_query = new WP_Query( $args );
if ( $custom_query->have_posts() ) {
while ( $custom_query->have_posts() ) {
$custom_query->the_post(); ?>
<div class="row">
<div class="col-md-2 col-sm-2 col-xs-2 divider">
<p class="date"><?php the_time('M j') ?></p>
</div><!--end col-->
<div class="col-md-4 col-sm-4 col-xs-4">
<div class="articleimg">
<?php if ( has_post_thumbnail()) {?>
<?php the_post_thumbnail('blog-thumb'); ?>
<?php } ?>
</div><!--end blogimg-->
</div><!--end col-->
<div class="col-md-6 col-sm-6 col-xs-6">
<div class="blogcontent">
<h3><?php the_title();?></h3>
<p><?php the_excerpt(); ?></p>
// read more
</div><!--end blogcontent-->
</div><!--end col-->
</div><!--end row-->
<?php }
}
echo paginate_links(array(
'total' => $custom_query->max_num_pages
));
wp_reset_postdata(); ?>
</section><!--end articles-->
</div><!--end col 2-->
</div> <!--end row-->
</section><!--end related-->

Answer 2

Thanks, Jo! That article pointed me in the right direction. I checked in dev tools and I was indeed getting a 301. I tried the code snippet from the article you pointed me to, and it didn't quite work, so I googled "fix pagination with redirect_canonical" and this was the first article that popped up. I took the function from there, threw it in to functions.php, et voilà! It's the same method, but, I think, not passing a custom post type into the conditional. I hope this can help someone in the future. It was a real pain. It was also a reminder of how very little I really know about WP and how much I want to learn about it! Thanks again.
Here's the code:
add_filter('redirect_canonical','custom_disable_redirect_canonical');
function custom_disable_redirect_canonical($redirect_url) {
if (is_paged() && is_singular()) $redirect_url = false;
return $redirect_url;
}