compile-post-meta-on-save.php

<?php


class Get_Words {

	public static $meta_compiled_words = 'awesome_words_compiled';
	public static $repeater_name_left = 'awesome_words_repeater_left';
	public static $repeater_name_right = 'awesome_words_repeater_right';

	public static $repeater_subfield = 'words';

	public static $cpt = 'wordpack';

	public function __construct() {
	}


	public function init() {
		add_action( 'save_post', [ $this, 'compile_words' ], 10, 2 );
	}


	/*
	 * Since this one is a bit longer, let's keep the get_words easier to read by splitting up
	 * the "compiling" routine
	 */
	public static function compile_words( $post_id, $post ) {

		// Only set for post_type = our cpt
		if ( self::$cpt !== $post->post_type ) {
			return;
		}


		$words = [
			'left'  => [],
			'right' => [],
		];


		// whatever logic you need to compile it all into a nice array that you'll re-use or pass to JS
		if ( function_exists( 'have_rows' ) && have_rows( self::$repeater_name_left, $post_id ) ) {
			while ( have_rows( self::$repeater_name_left, $post_id ) ) {
				the_row();

				$words['left'][] = get_sub_field( self::$repeater_subfield );

			}
		}

		// droite
		if ( function_exists( 'have_rows' ) && have_rows( self::$repeater_name_right, $post_id ) ) {
			while ( have_rows( self::$repeater_name_right, $post_id ) ) {
				the_row();

				$words['right'][] = get_sub_field( self::$repeater_subfield );

			}
		}

		update_post_meta( $post_id, self::$meta_compiled_words, $words );


	}


	// Can simply call Get_Words::get_words() or Get_Words::get_words( $post_id )   anywhere
	public static function get_words( $post_id = false ) {
		if ( empty( $post_id ) ) {
			global $post;
			$post_id = $post->ID;
		}

		return get_post_meta( $post_id, self::$meta_compiled_words, true  );
	}


}

$get_words = new Get_Words();
$get_words->init();