Add Custom Field to Post Pages via Plugin

Question

I am creating a field that needs to add a custom field to every post on a site. I am using the ACF plugin in my plugin to do so. I have followed this tutorial and am close. In the tutorial they add the custom fields to a settings back, but I want to add the custom field to every post. Here is the ACF-related code that I have:

<?php
// 1. customize ACF path
add_filter('acf/settings/path', 'my_acf_settings_path');
function my_acf_settings_path( $path ) {
    // update path
    $path = get_stylesheet_directory() . '/vendor/advanced-custom-fields/';
    // return
    return $path;
}

// 2. customize ACF dir
add_filter('acf/settings/dir', 'my_acf_settings_dir');
function my_acf_settings_dir( $dir ) {
    // update path
    $dir = get_stylesheet_directory_uri() . '/vendor/advanced-custom-fields/';
    // return
    return $dir;
}

// 3. Hide ACF field group menu item
add_filter('acf/settings/show_admin', '__return_false');

// 4. Include ACF
include_once( get_stylesheet_directory() . '/vendor/advanced-custom-fields/acf.php' );

// 5. Setup Custom Fields on post pages
$this->setup_options();
public function setup_options() {
  if(function_exists("register_field_group")) {
    register_field_group(array (
      'id' => 'acf_field-id',
      'title' => 'Field Name',
      'fields' => array (
        array (
          'key' => 'field_5ab8f6946d890',
          'label' => 'Label',
          'name' => 'name',
          'type' => 'wysiwyg',
          'instructions' => '',
          'default_value' => '',
          'toolbar' => 'full',
          'media_upload' => 'yes',
        ),
      ),
      'location' => array (
        array (
          array (
            'param' => 'post_type',
            'operator' => '==',
            'value' => 'post',
            'order_no' => 0,
            'group_no' => 0,
          ),
        ),
      ),
      'options' => array (
        'position' => 'normal',
        'layout' => 'no_box',
        'hide_on_screen' => array (
        ),
      ),
      'menu_order' => 0,
    ));
  }
}

I know my issue is in #5 above. I am not clear how to run the function to load that field for every post. Any insight?

Also, how would I then automatically output this field code in the single.php template before the post content. Can I use a WordPress function to do that as well?

Answer 1

You can use wordpress plugin - Advanced Custom Fields to set up your desired fields. https://wordpress.org/plugins/advanced-custom-fields/

To print custom field value, please refer plugin documentation.

Answer 2

Your #5 looks fine to me. The 'location' section states that it should attach to every post_type equal to type post. That custom field 'Label' should now appear on the post edit page.

To get your field data in single.php you would then use

$data = function_exists( 'get_field' ) ? get_field( 'name', get_the_ID() ) : null;