如何检查 wordpress 查询是否有更多帖子？

Question

So i am using ajax to filter and load posts into a container. I want to limit the amount of posts to 6 at a time and add a load more button underneath if there are more than 6 posts, but i don't want to add pages because i have a few containers on the same page that i'm using this same treatment for and my understanding is pages would add a /page-1 or something like that to the url (am i wrong?).

Either way, i just want to know how to check if there are more posts that fit this criteria so i can show the load more button, and then when the load more button fires how do i just load 6 more. Do i have to keep a page variable somewhere? or is there another smarter way.

Here is my query

function ajax_filter_get_posts( $category, $tag ) 
{
  $category = $_POST['category'];
  $tag = $_POST['tag'];

  if($category)
  {
    $category_args = array(
      'taxonomy' => 'category',
      'field'    => 'slug',
      'terms'    => $category
    );
  }

  $args = array(
    'posts_per_page' => 6,
    'post_status'    => 'publish',
    'tag'            => implode(",",$tag),
    'tax_query'      => array(
      $category_args,
    ),
    'category__in'      => array(187,186,183,182,184),
  );

  $query = new WP_Query( $args );

  if ( $query->have_posts() ) : while ( $query->have_posts() ) : $query->the_post();

    $output = post_factory($post);

    $result['response'][] = $output;
    $result['status']     = 'success';

  endwhile; else:
    $result['response'] = '<h2>No posts found</h2>';
    $result['status']   = '404';
  endif;

  $result = json_encode($result);
  echo $result;

  die();
}

Answer 1

I know this post is about a year old, but in case anyone else needs an answer, here's the solution I'm implementing. I'm using Ajax to pull in a wp_query from a PHP file. The output from that file replaces the content of a div on my page. This is only the relevant code, not my complete code.

On click of the load more button, I use jQuery to count the number of posts on the page and put that count into a variable. Posts have a unique class assigned to them.

current = $('.item').length;

I send the post count to the PHP file using Ajax.

$.get(functions_home.url, { offset: current }, function(data) {
    $('.grid').html(data);
}

I pull the post count from jQuery into a variable in the PHP file, and then use that variable to set the wp_query "offset" in $args.

$offset = $_GET['offset'];

$args = array (
    'offset' => $offset
);

Once the query ($query) runs, I use $query->found-posts to tell me the total number of relevant posts, and I put that in a variable.

$total = $query->found_posts;

I make a div in my PHP file and use the found posts variable so that it's populated with the total number of relevant posts. I use CSS to hide that div, so that it's never visible on the website.

<div id="total"><?php echo $total; ?></div>

#total {
    display: none;
}

I use jQuery to find that div on the page, and get the text from it, which is the total number of relevant posts. I put that in a variable.

total = $('#total').text();

I use jQuery to check whether the number of posts on the page is equal to the total number of posts, and, if it is, I hide the load more button. For my particular situation, I check in both the initial Ajax load and the Ajax call that fires when the load more button is clicked.

current = $('.item').length;
total = $('#total').text();

if ( current == total ) {

    $('.load-more').css({
        display: 'none'
    });

}

I don't know if this is the best solution, or even a good solution, but it's what I've figured out to do, and it's working for me so far.

Answer 2

WP_Query has a parameter max_num_posts which will tell you how many pages in total the query have. Inside the callback function you can check if there any more pages left in a query and send the value in response. Than you will be able to hide/show "load more" button with JS function based on that value. You can something similar to this:

function ajax_filter_get_posts( $category, $tag, $paged = 1 ) 
{
  $paged = $_POST['paged']; // Pass a number of a page that you want to retrieve. Default is page #1
  $category = $_POST['category'];
  $tag = $_POST['tag'];

  if($category)
  {
    $category_args = array(
      'taxonomy' => 'category',
      'field'    => 'slug',
      'terms'    => $category
    );
  }

  $args = array(
    'posts_per_page' => 6,
    'paged'          => $paged, // pass required page number to WP_Query
    'post_status'    => 'publish',
    'tag'            => implode(",",$tag),
    'tax_query'      => array(
      $category_args,
    ),
    'category__in'      => array(187,186,183,182,184),
  );

  $query = new WP_Query( $args );

  if ( $query->have_posts() ) : while ( $query->have_posts() ) : $query->the_post();

    $output = post_factory($post);

    $result['response'][] = $output;
    $result['status']     = 'success';

  endwhile; else:
    $result['response'] = '<h2>No posts found</h2>';
    $result['status']   = '404';
  endif;

  // Check if there are any more pages to query and pass the boolean value in response 
  $result['more_pages'] = ( ( $query->max_num_pages - $paged ) > 0 ) ? true : false;

  $result = json_encode($result);
  echo $result;

  die();
}