How to update custom meta data based on certain conditions in WooCommerce

Question

I have a some product custom fields in WooCommerce and it works well. Here's the code:

add_action( 'woocommerce_product_options_advanced', 'meta_data_custom' );
function meta_data_custom() {

  // 1. Partner ID
  woocommerce_wp_text_input( array(
      'id'            => '_idpartner',
      'label'         => __( 'Partner ID', 'woocommerce' ),
      'description'   => __( 'Fill in your partner ID.', 'woocommerce' ),
      'desc_tip'      => true,
      'placeholder'   => __( 'Ex : P1', 'woocommerce' )
  ) );

  // 2. Referral ID
  woocommerce_wp_text_input( array(
      'id'            => '_idreferral',
      'label'         => __( 'Referral ID', 'woocommerce' ),
      'description'   => __( 'Fill in your referral ID.', 'woocommerce' ),
      'desc_tip'      => true,
      'placeholder'   => __( 'Ex : R1', 'woocommerce' )
  ) );  
}

// Save custom field
add_action( 'woocommerce_admin_process_product_object', 'action_woocommerce_admin_process_product_object_meta_data_custom', 10, 3 );
function action_woocommerce_admin_process_product_object_meta_data_custom($product){
    // 1. ID Partner
    if ( isset( $_POST['_idpartner'] ) ) {        
        // Update
        $product->update_meta_data( '_idpartner', sanitize_text_field( $_POST['_idpartner'] ) );
    }

    // 1. ID Referral
    if ( isset( $_POST['_idreferral'] ) ) {        
        // Update
        $product->update_meta_data( '_idreferral', sanitize_text_field( $_POST['_idreferral'] ) );
    }   
}

Both the Partner ID and the Referral ID, must be filled in before the product is published. All Partner ID already have a referral ID except for (Partner ID == P1). So, I want to fill referral ID automatically other than partner ID P1.

So far I have tried :

function update_meta_data_custom(){
    
    global $product;
    
    $idpartner  = $product->get_meta('_idpartner');
    $idreferral = $product->get_meta('_idreferral');
    
    //Set referral id Obtained from user meta dinamically
    $idreferral = "R13";//examples only

    if(!empty($idpartner)){
        if($idpartner !== "P1"){
            
            //$product->update_meta_data( '_idreferral', sanitize_text_field( $_POST['_idreferral'] ) );
            //update _idreferral with $idreferral
        }
        else{
            if(!$idreferral){
                //Give a message to update referral ID or no need to do anything
                //Just in case something by human error
            }
            else{
                //No need to do anything or keep the data
            }
        }
    }
    else{
        //Give a message to update partner ID or no need to do anything 
        //Just in case something by human error
    }
}

but not sure how to achieve it.

Can someone walk me through how to do that?

Answer 1

Note that you will need to replace in the second function below, $referral_id = "R13"; with the code for referral ID obtained dynamically from user meta.

So you can implement your custom metadata update based on certain conditions replacing your current code, with the following:

// Display custom input fields settings to admin single product
add_action( 'woocommerce_product_options_advanced', 'admin_product_display_custom_input_fields' );
function admin_product_display_custom_input_fields() {
    ## 1. Partner ID 
    woocommerce_wp_text_input( array(
        'id'            => '_idpartner',
        'label'         => __( 'Partner ID', 'woocommerce' ),
        'description'   => __( 'Fill in your partner ID.', 'woocommerce' ),
        'desc_tip'      => true,
        'placeholder'   => __( 'Ex : P1', 'woocommerce' )
    ) );

    ## 2. Referral ID 
    woocommerce_wp_text_input( array(
        'id'            => '_idreferral',
        'label'         => __( 'Referral ID', 'woocommerce' ),
        'description'   => __( 'Fill in your referral ID.', 'woocommerce' ),
        'desc_tip'      => true,
        'placeholder'   => __( 'Ex : R1', 'woocommerce' )
    ) ); 
}

// Save custom input fields values for admin single product
add_action( 'woocommerce_admin_process_product_object', 'admin_product_save_custom_fields_values' );
function admin_product_save_custom_fields_values( $product ){
    ## 1. Partner ID 
    $partner_id = isset($_POST['_idpartner']) ? sanitize_text_field($_POST['_idpartner']) : '';
    $product->update_meta_data( '_idpartner', $partner_id ); // Update
    
    ## 2. Referral ID 
    if ( $partner_id === 'P1' ) {
        // Replace with the code for referral ID obtained dynamically from user meta
        $referral_id = "R13"; // <== Your code HERE
    }
    else {
        $referral_id = isset($_POST['_idreferral']) ? sanitize_text_field($_POST['_idreferral']) : '';
    }
    $product->update_meta_data( '_idreferral', $referral_id ); // Update
}

// Display product custom field admin notice
add_action( 'admin_notices', 'throw_error_admin_notice_Product_custom_fields' );
function throw_error_admin_notice_Product_custom_fields(){
    global $pagenow, $typenow, $post_id;

    if( $pagenow === 'post.php' && $typenow === 'product' && $post_id > 0 ) ) {
        $product = wc_get_product($post_id);

        if( ! is_a($product, 'WC_Product') ) return;

        $partner_id  = $product->get_meta('_idpartner');
        $referral_id = $product->get_meta('_idreferral');

        if ( empty($partner_id) && empty($referral_id) ) {
            printf( '<div class="notice error is-dismissible"><p>%s</p></div>',
            __( 'The Partner ID and Referral ID have not been saved yet.', 'woocommerce' ) );
        } elseif ( empty($partner_id) ) {
            printf( '<div class="notice error is-dismissible"><p>%s</p></div>',
            __( 'The Partner ID has not been saved yet.', 'woocommerce' ) );
        } elseif ( empty($referral_id) ) {
            printf( '<div class="notice error is-dismissible"><p>%s</p></div>',
            __( 'The Referral ID has not been saved yet.', 'woocommerce' ) );
        }
    }
}

Code goes in functions.php file of your child theme (or in a plugin). It should work

When saving/updating the product, if the Partner ID or/and the Referral ID are empty, an error notice will be displayed.