Syncs ACF JSON upon theme activation

acf-theme-activation-sync.php

<?php
/**
 * Sets path for ACF json
 * This is going to generate local JSON copies in your given folder for each ACF Group.
 * When the ACF Group is saved/updated,
 */
define( 'IP_ACF_PLUGIN_DIR_PATH', untrailingslashit( plugin_dir_path( __FILE__ ) ) );

function ip_acf_json_save_point( $path ) {
    // Update path
    $path = IP_ACF_PLUGIN_DIR_PATH . '/acf-json';
    // Return path
    return $path;
}
add_filter( 'acf/settings/save_json', 'ip_acf_json_save_point' );

/**
 * Sets the load for ACF json
 *
 * Register the path to load the ACF json files so that they are version controlled.
 * @param $paths The default relative path to the folder where ACF saves the files.
 * @return string The new relative path to the folder where we are saving the files.
 */
function ip_acf_json_load_point( $paths ) {
   // Remove original path
   unset( $paths[0] );// Append our new path
   $paths[] = IP_ACF_PLUGIN_DIR_PATH . '/acf-json';
   return $paths;
}
add_filter( 'acf/settings/load_json', 'ip_acf_json_load_point' );

/**
 * Adds auto sync for ACF json
 * When the them is distributed, on activation it will also activate ACF, then copy all the json files and execute them.
 * This should automatically sync all the field groups.
 * The ACF plugin can now be hidden, none of the users have to go inside ACF to sync fields.
 */
function ip_sync_acf_fields() {
    // vars
    $groups = acf_get_field_groups();
    $sync   = array();

	// bail early if no field groups
    if ( empty( $groups ) ) {
        return;
	}

    // find JSON field groups which have not yet been imported
    foreach ( $groups as $group ) {
        // vars
        $local      = acf_maybe_get( $group, 'local', false );
        $modified   = acf_maybe_get( $group, 'modified', 0 );
        $private    = acf_maybe_get( $group, 'private', false );

        // ignore DB / PHP / private field groups
        if ( $local !== 'json' || $private ) {
            // do nothing
        } elseif ( ! $group[ 'ID' ] ) {
            $sync[ $group[ 'key' ] ] = $group;
        } elseif ( $modified && $modified > get_post_modified_time( 'U', true, $group[ 'ID' ], true ) ) {
            $sync[ $group[ 'key' ] ]  = $group;
        }
    }

    // bail if no sync needed
    if ( empty( $sync ) ) {
        return;
	}

	//if( ! empty( $keys ) ) {
    if ( ! empty( $sync ) ) {
        // vars
        $new_ids = array();

		//foreach( $keys as $key ) {
        foreach ( $sync as $key => $v ) {
            // append fields
            if( acf_have_local_fields( $key ) ) {
                $sync[ $key ][ 'fields' ] = acf_get_local_fields( $key );
            }

            // import
            $field_group = acf_import_field_group( $sync[ $key ] );
        }
    }
}
add_action( 'admin_init', 'ip_sync_acf_fields' );