How can I pass a variable from functions.php to the template file in WordPress?

Question

I can't access my variables inside my template file (see comment below). thanks in advance for the help.

functions.php:

$mypage = (get_query_var('paged')) ? get_query_var('paged') : 1;
$maxpost = $loop->max_num_pages;

template.php:

$args = array(
          'post_type' => 'publications',
          'posts_per_page' => 2,
      );

    $query = new WP_Query( $args ); ?>

    <?php if ($query->have_posts()) : ?>
      <div id="posts">
        <?php while ($query->have_posts()) : $query->the_post(); ?>
          <section class="col-sm-10 col-sm-offset-1 col-md-8 col-md-offset-2  publications-section tagged-posts post">
            <?php if ( has_post_thumbnail() ) : ?>
            <a href="<?php echo get_permalink( $post->ID ); ?>">
              <div class="col-sm-4 col-sm-push-8 publications-section-image" style="background-image:url('<?php the_post_thumbnail_url(); ?>');"></div>
            </a>
            <?php endif; ?>
            <div class="col-sm-8 col-sm-pull-4">
             <h2><a href="<?php echo get_permalink( $post->ID ); ?>"><?php the_title(); ?></a></h2>
             <p><?php the_excerpt(); ?></p>
             <small><?php echo get_post_meta($post->ID, "_contact", true); ?></small>
             <small class="pub-tags pub"> <span><?php the_terms( $post->ID,'mytag','',' '); ?></span></small>
           </div>
          </section>
        <?php echo $mypage; endwhile; wp_reset_postdata();  ?>
      </div>

      <div class="col-sm-10 col-sm-offset-1 col-md-8 col-md-offset-2" id="pub-btn-section">
        <input type="submit" class="btn" id="loadmore" name="" value="Submit">
      </div>
    <?php endif;  ?>

Answer 1

let's assume that your are used the get_template_part() function to include template in function.php file.

now pass some value with this you can used the set_query_var() function above the get_template_part()

functions.php code

$mypage = (get_query_var('paged')) ? get_query_var('paged') : 1;
$mymax = $loop->max_num_pages;
set_query_var( 'mypage', absint( $mypage ) );
set_query_var( 'mymax', absint( $mymax) );
get_template_part(  'The slug name for the generic template', $name = null  );

In template.php file, we need to access the $mypage and mymax variable directly

echo $mypage;
echo $mymax;

Answer 2

1. You need to declare your global variable in functions.php outside of any functions first, and you do this without the global keyword.

2. When you want to reference the global variable when its out of scope (eg in a function, in another file), that's when you used the global keyword.

functions.php :

// declare your global variables
$mypage = 0;
$mymax = 0;

function myfunction(){
    global $mypage,$mymax; // reference your global variables

    $mypage = (get_query_var('paged')) ? get_query_var('paged') : 1;
    $mymax = $loop->max_num_pages;
}

Now you should be able to access it in template.php, depending on what hook you are using (as long as that hook isn't called too early.

NOTE:

The use of global variables is strongly discouraged, so consider why you're doing it this way... could the logic of your code be changed, or a custom function be used instead??

Another option is to use get_query_var() and set_query_var() - although these are intended for passing parameters instead of on the querystring.

functions.php

$mypage = (get_query_var('paged')) ? get_query_var('paged') : 1;
set_query_var("mypage", $mypage );    // set your variable

template.php

$mypage = get_query_var("mypage"); // get the variable

Again, these depend on where in the sequence of actions the hook you are using is.

Update :

If your paging variables are in a function that includes a template_part , in that case you would use include(locate_template('your-template-part.php')); after setting them to pass them to that file.