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wordpresswoocommercebackendproduct

Add custom fields to WooComerce product setting pages in the shipping tab and apply automatic calculations based on the values

Based on the answers to the following questions:

I managed to create two extra fields in the WooCommerce Shipping Options:

  • Field to add loading meters
  • Field to add shipping weight

These fields will get a value either by an admin user editing the field, either by a calculation that helps us to prefill the field with a value.

Underneath snippet shows the creation of the field by adding the snippets to the functions.php file.

add_action('woocommerce_product_options_shipping', function() {
  
    woocommerce_wp_text_input( 
        array( 
            'id'            => '_loading_meters', 
            'label'         => __('Loading meters', 'woocommerce'), 
            'desc_tip'      => 'true',
            'description'   => __( 'Vul hier de laadmeters in', 'woocommerce' ),
            'type'          => 'number',
            'custom_attributes' => array(
                            'step'  => 'any',
                            'min'   => '0'
                        ) 
        )
    );      

    woocommerce_wp_text_input( 
        array( 
            'id'            => '_loading_weight', 
            'label'         => __('Loading weight', 'woocommerce'), 
            'desc_tip'      => 'true',
            'description'   => __( 'Vul hier het laadgewicht in', 'woocommerce' ),
            'type'          => 'number',
            'custom_attributes' => array(
                            'step'  => 'any',
                            'min'   => '0'
                        ) 
        )
    );
    
});

The second snippet is saving the values that were manually added by the admin user. This snippet is also added to the functions.php file.

add_action('woocommerce_process_product_meta', function($post_id) {
    $product = wc_get_product($post_id);
    $num_loading_meters = isset($_POST['_loading_meters']) ? $_POST['_loading_meters'] : '';
    $num_loading_weight = isset($_POST['_loading_weight']) ? $_POST['_loading_weight'] : '';
    $product->update_meta_data('_loading_meters', sanitize_text_field($num_loading_meters));
    $product->update_meta_data('_loading_weight', sanitize_text_field($num_loading_weight)); $product->save();
});

As an end result, I would like to achieve both field filled in automatically using a calcuation, but still being editable by an admin user.

The calculation for the loading meters:

  • (lenght (m)) x (height (m)) / 2.4

The calculation for the loading weight:

  • Loading meters * 1750

Is there anyone who can point me in the right direction?

Solution

  • For the calculation you can use $product->get_length() and $product->get_height()

    The calculation can be saved automatically, but be aware that if you are going to adjust the values ​​manually you have to indicate this somewhere. Otherwise the automatic calculation will be overwritten by the manually entered values ​​or vice versa when saving.

    To prevent this, I have added an extra field, namely a checkbox. When checked, the manually entered values ​​will be saved, if not, the calculation will be performed automatically and these values ​​will be saved

    So you get:

    // Add custom fields to product shipping tab
function action_woocommerce_product_options_shipping() {
    // Checkbox
    woocommerce_wp_checkbox( 
        array( 
        'id'             => '_loading_checkbox',
        'label'          => __( 'My checkbox', 'woocommerce' ),
        'desc_tip'       => false,
        'description'    => __( 'If this is checked, the values ​​entered manually will be saved against the values ​​of the automatic calculation', 'woocommerce' )
        )
    );
    
    // Field loading meters
    woocommerce_wp_text_input(
        array( 
            'id'                => '_loading_meters', 
            'label'             => __( 'Loading meters', 'woocommerce' ), 
            'desc_tip'          => true,
            'description'       => __( 'Vul hier de laadmeters in', 'woocommerce' ),
            'type'              => 'number',
            'custom_attributes' => array(
                'step'  => 'any',
                'min'   => '0'
            )
        )
    );
    
    // Field loading weight
    woocommerce_wp_text_input( 
        array( 
            'id'                => '_loading_weight', 
            'label'             => __('Loading weight', 'woocommerce'), 
            'desc_tip'          => true,
            'description'       => __( 'Vul hier het laadgewicht in', 'woocommerce' ),
            'type'              => 'number',
            'custom_attributes' => array(
                'step'  => 'any',
                'min'   => '0'
            )
        )
    );
}
add_action( 'woocommerce_product_options_shipping', 'action_woocommerce_product_options_shipping', 10, 0 );

// Save
function action_woocommerce_admin_process_product_object( $product ) {
    // Checkbox has been checked
    if ( isset( $_POST['_loading_checkbox'] ) ) {
        // Isset
        if ( isset( $_POST['_loading_meters'] ) ) {
            $product->update_meta_data( '_loading_meters', sanitize_text_field( $_POST['_loading_meters'] ) );
        }
        
        // Isset
        if ( isset( $_POST['_loading_weight'] ) ) {
            $product->update_meta_data( '_loading_weight', sanitize_text_field( $_POST['_loading_weight'] ) );
        }
    } else {
        // Initialize
        $loading_meters = '';
        
        // Isset
        if ( isset( $_POST['_loading_meters'] ) ) {
            // Get values
            $height = $product->get_length();
            $length = $product->get_height();

            // NOT empty
            if ( ! empty( $height ) && ! empty( $length ) ) {
                // Calculation
                $loading_meters = ( $length * $height ) / 2.4;
                
                // Update meta
                $product->update_meta_data( '_loading_meters', $loading_meters );
            }
        }

        // Isset and NOT empty
        if ( isset( $_POST['_loading_weight'] ) && ! empty( $loading_meters ) ) {
            // Calculation
            $loading_weight = $loading_meters * 1750;
            
            // Update meta
            $product->update_meta_data( '_loading_weight', $loading_weight );
        }
    }
}
add_action( 'woocommerce_admin_process_product_object', 'action_woocommerce_admin_process_product_object', 10, 1 );

    Result:

    enter image description here