get_posts custom field

Question

This is a silly question, but I can't find the proper way to ask it to google. so, sorry if this is a repetitive question.

I give a custom field with a checked that the user can check if he want this specific post to go the home page. So in my home page, I call for all the post who has the checked activated.

I am creating my custom field for the custom post type CV:

function add_custom_post_meta_box() {
    add_meta_box(
        'custom_post_meta_box', // $id
        'Campos Personalizados', // $title
        'show_custom_post_meta_box', // $callback
        'cv', // $screen
        'normal', // $context
        'high' // $priority
    );
}
add_action( 'add_meta_boxes', 'add_custom_post_meta_box' );

But inside this custom post meta box, I have multiple fields, like a label and a checkbox:

function show_custom_post_meta_box() {
    global $post;
        $meta = get_post_meta( $post->ID, 'your_fields', true ); ?>
  <p>
    <label for="your_fields[text]">Especialidad</label>
    <br>
    <input type="text" name="your_fields[text]" id="your_fields[text]" class="regular-text" value="
    <?php if (is_array($meta) && isset($meta['text'])){ echo $meta['text'];} ?>">
  </p>
  <p>
    <label for="your_fields[checkbox]">Mostrar en Home
        <input type="checkbox" name="your_fields[checkbox]" value="checkbox"
      <?php
      if (is_array($meta) && isset($meta['checkbox'])){
        if ( $meta['checkbox'] === 'checkbox' ) echo 'checked';
      }
      ?>>
    </label>
  </p>

Okey, the rest of the code save the custom field and works perfectly. My problem is when I try to call it:

$posts = get_posts(array(
    'posts_per_page'    => -1,
    'post_type'         => 'cv'
    // 'meta_key'       => 'your_fields[checkbox]', //This is wrong!!
    // 'meta_value' => 'checkbox'
));

And when I try to call the post info:

<?php
        foreach( $posts as $post ):
            setup_postdata( $post );
        ?>

              <h2><a href="<?php the_permalink() ?>"><?php the_title(); ?></a></h2>
              <p>
                <?php
                  $meta = get_post_meta( $post->ID, 'your_fields', true );
                  if (isset($meta['checkbox'])){
                    echo $meta['checkbox'];
                  }
                ?>
              </p>
       <?php endforeach; ?>

So, my question is: How can make my query, to bring me just the custom post types, with a checked activated.

Answer 1

If you want to use post meta for setting which posts are displayd on the front page, then I would recommend saving the setting with a separate meta_key. So instead of pushing it to the your_fields save it with its own key.

This means modifying your metabox content to have something like this,

<input type="checkbox" name="show_on_front_page" value="true"

Please modifiy your metabox saving box also accordingly.

Then you should be able to use the get_posts like so,

$posts = get_posts(array(
    'posts_per_page'    => -1,
    'post_type'         => 'cv',
    'meta_key'       => 'show_on_front_page',
    'meta_value' => 'true'
));

But just yesterday I saw a comment by Mr. Tom J Nowell on some other thread, that this is rather inefficient way of setting front page posts. On a larger site this could, in the worst case scenario, grind your site's server to a halt.

You would be better off using a (private) custom taxonomy to which you would assign posts you want to show on the front page. Getting posts with a certain taxonomy from the database is faster and more efficient way of doing things.

From Mr. Nowell's blog, https://tomjn.com/2018/03/16/utility-taxonomies/

Set up custom taxonomy,

function tomjn_utility_taxonomy() {
$args = array(
    'label'     => __( 'Internal Markers', 'tomjn' ),
    'public'    => false,
    'rewrite'   => false,
    'show_ui'   => true, // you'd need this if you want to show the taxonomy metabox on the post edit screen
);
register_taxonomy( 'utility', 'post', $args );
}
add_action( 'init', 'tomjn_utility_taxonomy', 0 );

Automate publishing to front page,

function tomjn_auto_add_to_home( $post_id ) {
wp_set_object_terms( $post_id, 'show_on_homepage', 'utility', true );
}
add_action( 'publish_post', 'tomjn_auto_add_to_home' );

adjust the homepage query

function tomjn_only_show_home( $query ) {
    if ( $query->is_home() && $query->is_main_query() ) {
        $query->set( 'utility', 'show_on_homepage' );
    }
}
add_action( 'pre_get_posts', 'tomjn_only_show_home' );

Please refer to the blog post for more detailed explanation.