How To Add Woocommerce Custom Product Fields | http://www.ibenic.com/how-to-add-woocommerce-custom-product-fields

checkbox_input.php

<?php
// @link https://github.com/woocommerce/woocommerce/blob/master/includes/admin/wc-meta-box-functions.php#L141

$args = array(
  'label' => '', // Text in Label
  'class' => '',
  'style' => '',
  'wrapper_class' => '',
  'value' => '', // if empty, retrieved from post meta where id is the meta_key
  'id' => '', // required
  'name' => '', //name will set from id if empty
  'cbvalue' => '',
  'desc_tip' => '',
  'custom_attributes' => '', // array of attributes 
  'description' => ''
);

woocommerce_wp_checkbox( $args );

feature_classes.php

<?php
/**
 * Show or hide tabs or sections or single option fields for specific product types
 *
 * Use some of these classes :
 * show_if_simple
 * show_if_grouped
 * show_if_external
 * show_if_variable
 * show_if_virtual
 * show_if_downloadable
 **/

general_tab.php

<?php
/**
 * General tab (priority 10) options group
 *
 * @link https://github.com/woocommerce/woocommerce/blob/master/includes/admin/meta-boxes/views/html-product-data-general.php
 *
 * woocommerce_product_options_pricing
 * woocommerce_product_options_downloads
 * woocommerce_product_options_tax
 **/

add_action( 'woocommerce_product_options_pricing', 'my_woo_custom_price_field' );
/**
 * Add a Christmas Price field to pricing options group
 **/
function my_woo_custom_price_field() {
  
  $field = array(
    'id' => 'christmas_price',
    'label' => __( 'Christmas Price', 'textdomain' ),
    'data_type' => 'price' //Let WooCommerce formats our field as price field
  );
  
  woocommerce_wp_text_input( $field );
}

add_action( 'woocommerce_product_options_general_product_data', 'my_woo_custom_fields' );
/**
* Add a select Field in a new general options group
*/
function my_woo_custom_fields() {
  echo '<div class="options_group">';

  $select_field = array(
    'id' => 'my_select',
    'label' => __( 'Custom Select', 'textdomain' ),
    'options' => array(
      'value1' => __( 'Text 1', 'textdomain' ),
      'value2' => __( 'Text 2', 'textdomain' )
    )
  );
  woocommerce_wp_select( $select_field );

  echo '</div>';
}

hidden_input.php

<?php
// @link https://github.com/woocommerce/woocommerce/blob/master/includes/admin/wc-meta-box-functions.php#L81

$args = array(
  'value' => '',
  'class' => '',
  'id' => ''
);

woocommerce_wp_hidden_input( $args );

other_default_tabs.php

<?php
/**
 * In addition to general tab (priority 10), here are the other default tabs :
 *
 * Inventory tab - Priority 20
 * @link https://github.com/woocommerce/woocommerce/blob/master/includes/admin/meta-boxes/views/html-product-data-inventory.php
 * First group :
 *    under stock sku settings – woocommerce_product_options_sku,
 *    under manage stocks settings – woocommerce_product_options_stock,
 *    under low stock threshold settings – woocommerce_product_options_stock_fields,
 *    under stock status settings – woocommerce_product_options_stock_status,
 * Second group – woocommerce_product_options_sold_individually.
 * Or add your custom group with woocommerce_product_options_inventory_product_data
 *
 *
 * Shipping tab - Priority 30
 * @link https://github.com/woocommerce/woocommerce/blob/master/includes/admin/meta-boxes/views/html-product-data-shipping.php
 * First group with product dimension – woocommerce_product_options_dimensions,
 * Second group – woocommerce_product_options_shipping.
 * Here is no hook for your custom options group 😱 but if you absolutely need it, you can do some tricks
 * with the second hook and closing </div> element :
 **/
add_action( 'woocommerce_product_options_shipping', 'my_woo_product_options_shipping_product_data' );
function my_woo_product_options_shipping_product_data() {
  echo '</div>';
  echo '<div class="options_group">';
  echo 'here is my new options group content...';

}
/**
 * Linked products tab - Priority 40
 * @link https://github.com/woocommerce/woocommerce/blob/master/includes/admin/meta-boxes/views/html-product-data-linked-products.php
 * Add your custom group with woocommerce_product_options_related
 *
 *
 * Attributes tab - Priority 50
 * @link https://github.com/woocommerce/woocommerce/blob/master/includes/admin/meta-boxes/views/html-product-data-attributes.php
 * Add your custom group with woocommerce_product_options_attributes
 *
 *
 * Variations tab - Priority 60
 * @link https://github.com/woocommerce/woocommerce/blob/master/includes/admin/meta-boxes/views/html-product-data-variations.php
 * Add your custom group with woocommerce_variable_product_before_variations
 * Add bulk edit options - woocommerce_variable_product_bulk_edit_actions
 *
 *
 * Advanced tab - Priority 70
 * @link https://github.com/woocommerce/woocommerce/blob/master/includes/admin/meta-boxes/views/html-product-data-advanced.php
 * Reviews option group – woocommerce_product_options_reviews
 * Add your custom group with woocommerce_product_options_advanced
 **/

radio_input.php

<?php
// @link https://github.com/woocommerce/woocommerce/blob/master/includes/admin/wc-meta-box-functions.php#L241

$args = array(
  'label' => '', // Text in Label
  'class' => '',
  'style' => '',
  'wrapper_class' => '',
  'value' => '', // if empty, retrieved from post meta where id is the meta_key
  'id' => '', // required
  'name' => '', //name will set from id if empty
  'options' => '', // Options for radio inputs, array
  'desc_tip' => '', 
  'description' => ''
);

woocommerce_wp_radio( $args );

save_product.php

<?php

add_action( 'woocommerce_process_product_meta', 'save_custom_field' );

function save_custom_field( $post_id ) {
  
  $custom_field_value = isset( $_POST['my_custom_input'] ) ? $_POST['my_custom_input'] : '';
  
  $product = wc_get_product( $post_id );
  $product->update_meta_data( 'my_custom_input', $custom_field_value );
  $product->save();

}

select_input.php

<?php
// @link https://github.com/woocommerce/woocommerce/blob/master/includes/admin/wc-meta-box-functions.php#L184

$args = array(
  'label' => '', // Text in Label
  'class' => '',
  'style' => '',
  'wrapper_class' => '',
  'value' => '', // if empty, retrieved from post meta where id is the meta_key
  'id' => '', // required
  'name' => '', //name will set from id if empty
  'options' => '', // Options for select, array
  'desc_tip' => '',
  'custom_attributes' => '', // array of attributes 
  'description' => ''
);

woocommerce_wp_select( $args );

tab_action.php

<?php

add_action( 'woocommerce_product_write_panel_tabs', 'my_custom_tab_action' );

/**
* Adding a custom tab
*/
function my_custom_tab_action() {
  ?>
  <li class="custom_tab">
    <a href="#the_custom_panel">
      <span><?php _e( 'My Custom Tab', 'textdomain' ); ?></span>
    </a>
  </li>
  <?php
}

tab_filter.php

<?php

add_filter( 'woocommerce_product_data_tabs', 'my_custom_tab' );
/**
* Adding a custom tab
*/
function my_custom_tab( $tabs ) {
  
  $tabs['custom_tab'] = array(
    'label'    => __( 'My Custom Tab', 'textdomain' ),
    'target'   => 'the_custom_panel',
    'class'    => array(),
    'priority' => 21, // general: 10, inventory: 20, shipping: 30, linked product: 40, attribute: 50, variations: 60, advanced: 70
  );
  
  return $tabs;
}

add_action( 'admin_head', 'my_custom_tab_css_icon' );
/**
 * Custom tab icon
 *
 * @link https://developer.wordpress.org/resource/dashicons/
 */
function my_custom_tab_css_icon(){
	echo '<style>#woocommerce-product-data ul.wc-tabs li.custom_tab_options a::before{content: "\f487";}</style>';
}

tab_panel.php

<?php

add_action( 'woocommerce_product_data_panels', 'custom_tab_panel' );

function custom_tab_panel() {
  ?>
  <div id="the_custom_panel" class="panel woocommerce_options_panel">
    <div class="options_group">
      <?php  
        $field = array(
          'id' => 'my_custom_input',
          'label' => __( 'Custom Input', 'textdomain' ),
        );

        woocommerce_wp_text_input( $field );
      ?>
    </div>
  </div>
<?php
}

text_input.php

<?php
// @link https://github.com/woocommerce/woocommerce/blob/master/includes/admin/wc-meta-box-functions.php#L14

$args = array(
  'label' => '', // Text in Label
  'placeholder' => '',
  'class' => '',
  'style' => '',
  'wrapper_class' => '',
  'value' => '', // if empty, retrieved from post meta where id is the meta_key
  'id' => '', // required
  'name' => '', //name will set from id if empty
  'type' => '',
  'desc_tip' => '',
  'data_type' => '',
  'custom_attributes' => '', // array of attributes 
  'description' => ''
);

woocommerce_wp_text_input( $args );

textarea_input.php

<?php
// @link https://github.com/woocommerce/woocommerce/blob/master/includes/admin/wc-meta-box-functions.php#L96

$args = array(
  'label' => '', // Text in Label
  'placeholder' => '',
  'class' => '',
  'style' => '',
  'wrapper_class' => '',
  'value' => '', // if empty, retrieved from post meta where id is the meta_key
  'id' => '', // required
  'name' => '', //name will set from id if empty
  'rows' => '',
  'cols' => '',
  'desc_tip' => '',
  'custom_attributes' => '', // array of attributes 
  'description' => ''
);

woocommerce_wp_textarea_input( $args );