Display ACF for woocommerce variations in backend

gistfile1.txt

// Render fields at the bottom of variations - does not account for field group order or placement.
add_action( 'woocommerce_product_after_variable_attributes', function( $loop, $variation_data, $variation ) {
    global $abcdefgh_i; // Custom global variable to monitor index
    $abcdefgh_i = $loop;
    // Add filter to update field name
    add_filter( 'acf/prepare_field', 'acf_prepare_field_update_field_name' );
    
    // Loop through all field groups
    $acf_field_groups = acf_get_field_groups();
    foreach( $acf_field_groups as $acf_field_group ) {
        foreach( $acf_field_group['location'] as $group_locations ) {
            foreach( $group_locations as $rule ) {
                // See if field Group has at least one post_type = Variations rule - does not validate other rules
                if( $rule['param'] == 'post_type' && $rule['operator'] == '==' && $rule['value'] == 'product_variation' ) {
                    // Render field Group
                    acf_render_fields( $variation->ID, acf_get_fields( $acf_field_group ) );
                    break 2;
                }
            }
        }
    }
    
    // Remove filter
    remove_filter( 'acf/prepare_field', 'acf_prepare_field_update_field_name' );
}, 10, 3 );

// Filter function to update field names
function  acf_prepare_field_update_field_name( $field ) {
    global $abcdefgh_i;
    $field['name'] = preg_replace( '/^acf\[/', "acf[$abcdefgh_i][", $field['name'] );
    return $field;
}
    
// Save variation data
add_action( 'woocommerce_save_product_variation', function( $variation_id, $i = -1 ) {
    // Update all fields for the current variation
    if ( ! empty( $_POST['acf'] ) && is_array( $_POST['acf'] ) && array_key_exists( $i, $_POST['acf'] ) && is_array( ( $fields = $_POST['acf'][ $i ] ) ) ) {
        foreach ( $fields as $key => $val ) {
            update_field( $key, $val, $variation_id );
        }
    }
}, 10, 2 );

Thank you for the code. I added the fields and have them showing in the backend but am modifying the template to bring the fields in. Do you happen to have a snippet to pull the fields into the frontend or could you point me in the right direction?

Works perfect! Thanks!

Fixed for repeater fields:

// Render fields at the bottom of variations - does not account for field group order or placement.
add_action( 'woocommerce_product_after_variable_attributes', function ( $loop, $variation_data, $variation ) {
    global $acf_variation; // Custom global variable to monitor index

    $acf_variation = $loop;
    // Add filter to update field name
    add_filter( 'acf/prepare_field', 'acf_prepare_field_update_field_name' );

    // Loop through all field groups
    $acf_field_groups = acf_get_field_groups();
    foreach ( $acf_field_groups as $acf_field_group ) {
        foreach ( $acf_field_group[ 'location' ] as $group_locations ) {
            foreach ( $group_locations as $rule ) {
                // See if field Group has at least one post_type = Variations rule - does not validate other rules
                if ( $rule[ 'param' ] == 'post_type' && $rule[ 'operator' ] == '==' && $rule[ 'value' ] == 'product_variation' ) {
                    // Render field Group
                    acf_render_fields( $variation->ID, acf_get_fields( $acf_field_group ) );

                    break 2;
                }
            }
        }
    }

    // Remove filter
    remove_filter( 'acf/prepare_field', 'acf_prepare_field_update_field_name' );
}, 10, 3 );

// Filter function to update field names
function acf_prepare_field_update_field_name( $field ) {
    global $acf_variation;

    $field[ 'name' ] = preg_replace( '/^acf\[/', "acf[$acf_variation][", $field[ 'name' ] );

    return $field;
}

// Save variation data
add_action( 'woocommerce_save_product_variation', function ( $variation_id, $i = -1 ) {
    // Update all fields for the current variation
    if ( !empty( $_POST[ 'acf' ] ) && is_array( $_POST[ 'acf' ] ) && array_key_exists( $i, $_POST[ 'acf' ] ) && is_array( ( $fields = $_POST[ 'acf' ][ $i ] ) ) ) {
        $unique_updates = array();
        foreach ( $fields as $key => $val ) {
            if ( strpos( $key, 'field_' ) === false ) {
                // repeater fields need to be parsed separately
                foreach ( $val as $repeater_key => $repeater_val ) {
                    if ( !array_key_exists( $repeater_key, $unique_updates ) || !empty( $repeater_val ) ) {
                        $unique_updates[ $repeater_key ] = $repeater_val;
                    }
                }
            } else {
                // non-repeater fields can be parsed normally
                // The repeater fields are repeated here, but empty. This causes the repeater that was updated above to be cleared
                if ( !array_key_exists( $key, $unique_updates ) || !empty( $val ) ) {
                    $unique_updates[ $key ] = $val;
                }
            }
        }
        // Only update each field once
        foreach ( $unique_updates as $key => $val ) {
            update_field( $key, $val, $variation_id );
        }
    }
}, 10, 2 );

// Add "Product Variation" location rule values
function my_acf_location_rule_values_post_type( $choices ) {
    $keys = array_keys( $choices );
    $index = array_search( 'product', $keys );

    $position = $index === false ? count( $choices ) : $index + 1;

    $choices = array_merge(
        array_slice( $choices, 0, $position ),
        array( 'product_variation' => __( 'Product Variation', 'auf' ) ),
        array_slice( $choices, $position )
    );

    return $choices;
}
add_filter( 'acf/location/rule_values/post_type', 'my_acf_location_rule_values_post_type' );

// Add "Product Variation" location rule match
function my_acf_location_rule_match_post_type( $match, $rule, $options, $field_group ) {
    if ( $rule[ 'value' ] == 'product_variation' && isset( $options[ 'post_type' ] ) ) {
        $post_type = $options[ 'post_type' ];

        if ( $rule[ 'operator' ] == "==" ) {
            $match = $post_type == $rule[ 'value' ];
        } elseif ( $rule[ 'operator' ] == "!=" ) {
            $match = $post_type != $rule[ 'value' ];
        }
    }

    return $match;
}
add_filter( 'acf/location/rule_match/post_type', 'my_acf_location_rule_match_post_type', 10, 4 );

//Campos imagen
function my_acf_input_admin_footer() {
?>
<script type="text/javascript">
  (function($) {
    $(document).on('woocommerce_variations_loaded', function () {
      acf.do_action('append', $('#post'));
    })
  })(jQuery);	
</script>
<?php
}
add_action( 'acf/input/admin_footer', 'my_acf_input_admin_footer' );

These snippets were very helpful and worked great! Thanks for sharing 👍

Thanks for sharing, very useful!

This is sooo good. Thank you. The last bit I'm really struggling with is getting at the saved data on the front end. I have variable products with a relationship field in each and I can edit and save data correctly on the back end, but I can't work out how to access that data on the front end. I've been trying to access it via the variation product's meta data but it isn't saved there - or at least it's not returned as part of the array in get_post_meta($variation_id);

Any ideas?

Hi @artprojectgroup, I need to populate "ordinary" acf fields and also relational fields for variable products. your snippet works perfect for relational fields while the other first one for the other acf fields. As I am not familiar whit coding I failed combining the two snippets into one. Can you please give me a hint? Or maybe you @nathanaelphilip or @sulym-roman ??

Hi, This custom fields appears on every variation product. You can't combine it with other location rules, Can you modify it please?