Wordpress: Let user select the number of posts sho

Question

I'm trying to build a function where the visitor can select the number of posts shown per page like this:

Where do I start and how do I achieve this? I am currently using query_post to list all the posts:

<?php 
$paged = 1;
query_posts(array( 'showposts'=> 10, 'post_type' => 'post', 'category_name' => 'jobseeker-announcements', 'order' => 'DESC', 'posts_per_page' => 10, 'paged' => get_query_var('paged'))); ?>
<?php while (have_posts()) : the_post(); ?>
<div class="post-list">
    <h3><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h3>
    <p class="datetime"><span>Date Posted:</span> <?php the_time('m/j/Y'); ?></p>
    <p><?php the_excerpt(); ?></p>
<!--/post-list--></div>
<?php endwhile; ?>

Answer 1

May be it's perfect code for your solution.

    <?php 

    if(isset($_GET['page'])){
        $posts_per_page = esc_sql($_GET['page']);
    } else {
         $posts_per_page = 10;
    }

    $paged = ( get_query_var( 'paged')) ? get_query_var( 'paged') : 1;

    query_posts(
        array( 
             'post_type' => 'post',
             'category_name' => 'jobseeker-announcements',
             'order' => 'DESC', 
             'posts_per_page' => $posts_per_page,
             'paged' => get_query_var('paged'))); 

    while (have_posts()) : the_post(); ?>

        <div class="post-list">
            <h3><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h3>
            <p class="datetime"><span>Date Posted:</span> <?php the_time('m/j/Y'); ?></p>
            <p><?php the_excerpt(); ?></p>
        </div>

    <?php endwhile; ?>

    <select class="page-select">
        <option value="10">10</option>
        <option value="20">20</option>
        <option value="20">30</option>
    </select>


    <script>

    jQuery.ready(function(){

        $('.page-select').change(function(){ 

        var checkIndex = window.location.href.indexOf('?');

        if( checkIndex > -1 ){
            var Link = window.location.href.substr(0, checkIndex-1);
            $(location).attr('href', Link+'?page='+$('.page-select').val());
        } else {
            $(location).attr('href', window.location.href+'?page='+$('.page-select').val());
        }

        });
    });

    </script>

Answer 2

Use jquery change function.

 <?php 
if(isset($_GET['pageVal'])){
  $showposts = esc_sql($_GET['pageVal']);
}else{
  $showposts = 10;
}
    $paged = 1;
    query_posts(array( 'showposts'=> $showposts, 'post_type' => 'post', 'category_name' => 'jobseeker-announcements', 'order' => 'DESC', 'posts_per_page' => $posts_per_page, 'paged' => get_query_var('paged'))); ?>
    <?php while (have_posts()) : the_post(); ?>
    <div class="post-list">
        <h3><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h3>
        <p class="datetime"><span>Date Posted:</span> <?php the_time('m/j/Y'); ?></p>
        <p><?php the_excerpt(); ?></p>
    <!--/post-list--></div>
    <?php endwhile; ?>

<select class='page-select'>
<option value='10'>10</option>
<option value='10'>20</option>
<option value='10'>30</option>
</select>
<script>
jQuery.ready(function(){
 $('.page-select').change(function(){
  $(location).attr('href', window.location.href+'?pageVal='+$('.page-select').val());
});
});
</script>