<form method="POST">
    <h3>Editing: class-wc-admin-permalink-settings.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php
/**
 * Adds settings to the permalinks admin settings page
 *
 * @class       WC_Admin_Permalink_Settings
 * @package     WooCommerce\Admin
 * @version     2.3.0
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

if ( class_exists( 'WC_Admin_Permalink_Settings', false ) ) {
	return new WC_Admin_Permalink_Settings();
}

/**
 * WC_Admin_Permalink_Settings Class.
 */
class WC_Admin_Permalink_Settings {

	/**
	 * Permalink settings.
	 *
	 * @var array
	 */
	private $permalinks = array();

	/**
	 * Hook in tabs.
	 */
	public function __construct() {
		$this-&gt;settings_init();
		$this-&gt;settings_save();
	}

	/**
	 * Init our settings.
	 */
	public function settings_init() {
		add_settings_section( 'woocommerce-permalink', __( 'Product permalinks', 'woocommerce' ), array( $this, 'settings' ), 'permalink' );

		add_settings_field(
			'woocommerce_product_category_slug',
			__( 'Product category base', 'woocommerce' ),
			array( $this, 'product_category_slug_input' ),
			'permalink',
			'optional'
		);
		add_settings_field(
			'woocommerce_product_tag_slug',
			__( 'Product tag base', 'woocommerce' ),
			array( $this, 'product_tag_slug_input' ),
			'permalink',
			'optional'
		);
		add_settings_field(
			'woocommerce_product_attribute_slug',
			__( 'Product attribute base', 'woocommerce' ),
			array( $this, 'product_attribute_slug_input' ),
			'permalink',
			'optional'
		);

		$this-&gt;permalinks = wc_get_permalink_structure();
	}

	/**
	 * Show a slug input box.
	 */
	public function product_category_slug_input() {
		?&gt;
		&lt;input name=&quot;woocommerce_product_category_slug&quot; type=&quot;text&quot; class=&quot;regular-text code&quot; value=&quot;&lt;?php echo esc_attr( $this-&gt;permalinks['category_base'] ); ?&gt;&quot; placeholder=&quot;&lt;?php echo esc_attr_x( 'product-category', 'slug', 'woocommerce' ); ?&gt;&quot; /&gt;
		&lt;?php
	}

	/**
	 * Show a slug input box.
	 */
	public function product_tag_slug_input() {
		?&gt;
		&lt;input name=&quot;woocommerce_product_tag_slug&quot; type=&quot;text&quot; class=&quot;regular-text code&quot; value=&quot;&lt;?php echo esc_attr( $this-&gt;permalinks['tag_base'] ); ?&gt;&quot; placeholder=&quot;&lt;?php echo esc_attr_x( 'product-tag', 'slug', 'woocommerce' ); ?&gt;&quot; /&gt;
		&lt;?php
	}

	/**
	 * Show a slug input box.
	 */
	public function product_attribute_slug_input() {
		?&gt;
		&lt;input name=&quot;woocommerce_product_attribute_slug&quot; type=&quot;text&quot; class=&quot;regular-text code&quot; value=&quot;&lt;?php echo esc_attr( $this-&gt;permalinks['attribute_base'] ); ?&gt;&quot; /&gt;&lt;code&gt;/attribute-name/attribute/&lt;/code&gt;
		&lt;?php
	}

	/**
	 * Show the settings.
	 */
	public function settings() {
		/* translators: %s: Home URL */
		echo wp_kses_post( wpautop( sprintf( __( 'If you like, you may enter custom structures for your product URLs here. For example, using &lt;code&gt;shop&lt;/code&gt; would make your product links like &lt;code&gt;%sshop/sample-product/&lt;/code&gt;. This setting affects product URLs only, not things such as product categories.', 'woocommerce' ), esc_url( home_url( '/' ) ) ) ) );

		$shop_page_id = wc_get_page_id( 'shop' );
		$base_slug    = urldecode( ( $shop_page_id &gt; 0 &amp;&amp; get_post( $shop_page_id ) ) ? get_page_uri( $shop_page_id ) : _x( 'shop', 'default-slug', 'woocommerce' ) );
		$product_base = _x( 'product', 'default-slug', 'woocommerce' );

		$structures = array(
			0 =&gt; '',
			1 =&gt; '/' . trailingslashit( $base_slug ),
			2 =&gt; '/' . trailingslashit( $base_slug ) . trailingslashit( '%product_cat%' ),
		);
		?&gt;
		&lt;table class=&quot;form-table wc-permalink-structure&quot;&gt;
			&lt;tbody&gt;
				&lt;tr&gt;
					&lt;th&gt;&lt;label&gt;&lt;input name=&quot;product_permalink&quot; type=&quot;radio&quot; value=&quot;&lt;?php echo esc_attr( $structures[0] ); ?&gt;&quot; class=&quot;wctog&quot; &lt;?php checked( $structures[0], $this-&gt;permalinks['product_base'] ); ?&gt; /&gt; &lt;?php esc_html_e( 'Default', 'woocommerce' ); ?&gt;&lt;/label&gt;&lt;/th&gt;
					&lt;td&gt;&lt;code class=&quot;default-example&quot;&gt;&lt;?php echo esc_html( home_url() ); ?&gt;/?product=sample-product&lt;/code&gt; &lt;code class=&quot;non-default-example&quot;&gt;&lt;?php echo esc_html( home_url() ); ?&gt;/&lt;?php echo esc_html( $product_base ); ?&gt;/sample-product/&lt;/code&gt;&lt;/td&gt;
				&lt;/tr&gt;
				&lt;?php if ( $shop_page_id ) : ?&gt;
					&lt;tr&gt;
						&lt;th&gt;&lt;label&gt;&lt;input name=&quot;product_permalink&quot; type=&quot;radio&quot; value=&quot;&lt;?php echo esc_attr( $structures[1] ); ?&gt;&quot; class=&quot;wctog&quot; &lt;?php checked( $structures[1], $this-&gt;permalinks['product_base'] ); ?&gt; /&gt; &lt;?php esc_html_e( 'Shop base', 'woocommerce' ); ?&gt;&lt;/label&gt;&lt;/th&gt;
						&lt;td&gt;&lt;code&gt;&lt;?php echo esc_html( home_url() ); ?&gt;/&lt;?php echo esc_html( $base_slug ); ?&gt;/sample-product/&lt;/code&gt;&lt;/td&gt;
					&lt;/tr&gt;
					&lt;tr&gt;
						&lt;th&gt;&lt;label&gt;&lt;input name=&quot;product_permalink&quot; type=&quot;radio&quot; value=&quot;&lt;?php echo esc_attr( $structures[2] ); ?&gt;&quot; class=&quot;wctog&quot; &lt;?php checked( $structures[2], $this-&gt;permalinks['product_base'] ); ?&gt; /&gt; &lt;?php esc_html_e( 'Shop base with category', 'woocommerce' ); ?&gt;&lt;/label&gt;&lt;/th&gt;
						&lt;td&gt;&lt;code&gt;&lt;?php echo esc_html( home_url() ); ?&gt;/&lt;?php echo esc_html( $base_slug ); ?&gt;/product-category/sample-product/&lt;/code&gt;&lt;/td&gt;
					&lt;/tr&gt;
				&lt;?php endif; ?&gt;
				&lt;tr&gt;
					&lt;th&gt;&lt;label&gt;&lt;input name=&quot;product_permalink&quot; id=&quot;woocommerce_custom_selection&quot; type=&quot;radio&quot; value=&quot;custom&quot; class=&quot;tog&quot; &lt;?php checked( in_array( $this-&gt;permalinks['product_base'], $structures, true ), false ); ?&gt; /&gt;
						&lt;?php esc_html_e( 'Custom base', 'woocommerce' ); ?&gt;&lt;/label&gt;&lt;/th&gt;
					&lt;td&gt;
						&lt;input name=&quot;product_permalink_structure&quot; id=&quot;woocommerce_permalink_structure&quot; type=&quot;text&quot; value=&quot;&lt;?php echo esc_attr( $this-&gt;permalinks['product_base'] ? trailingslashit( $this-&gt;permalinks['product_base'] ) : '' ); ?&gt;&quot; class=&quot;regular-text code&quot;&gt; &lt;span class=&quot;description&quot;&gt;&lt;?php esc_html_e( 'Enter a custom base to use. A base must be set or WordPress will use default instead.', 'woocommerce' ); ?&gt;&lt;/span&gt;
					&lt;/td&gt;
				&lt;/tr&gt;
			&lt;/tbody&gt;
		&lt;/table&gt;
		&lt;?php wp_nonce_field( 'wc-permalinks', 'wc-permalinks-nonce' ); ?&gt;
		&lt;script type=&quot;text/javascript&quot;&gt;
			jQuery( function() {
				jQuery('input.wctog').on( 'change', function() {
					jQuery('#woocommerce_permalink_structure').val( jQuery( this ).val() );
				});
				jQuery('.permalink-structure input').on( 'change', function() {
					jQuery('.wc-permalink-structure').find('code.non-default-example, code.default-example').hide();
					if ( jQuery(this).val() ) {
						jQuery('.wc-permalink-structure code.non-default-example').show();
						jQuery('.wc-permalink-structure input').prop('disabled', false);
					} else {
						jQuery('.wc-permalink-structure code.default-example').show();
						jQuery('.wc-permalink-structure input:eq(0)').trigger( 'click' );
						jQuery('.wc-permalink-structure input').attr('disabled', 'disabled');
					}
				});
				jQuery('.permalink-structure input:checked').trigger( 'change' );
				jQuery('#woocommerce_permalink_structure').on( 'focus', function(){
					jQuery('#woocommerce_custom_selection').trigger( 'click' );
				} );
			} );
		&lt;/script&gt;
		&lt;?php
	}

	/**
	 * Save the settings.
	 */
	public function settings_save() {
		if ( ! is_admin() ) {
			return;
		}

		// We need to save the options ourselves; settings api does not trigger save for the permalinks page.
		if ( isset( $_POST['permalink_structure'], $_POST['wc-permalinks-nonce'], $_POST['woocommerce_product_category_slug'], $_POST['woocommerce_product_tag_slug'], $_POST['woocommerce_product_attribute_slug'] ) &amp;&amp; wp_verify_nonce( wp_unslash( $_POST['wc-permalinks-nonce'] ), 'wc-permalinks' ) ) { // WPCS: input var ok, sanitization ok.
			wc_switch_to_site_locale();

			$permalinks                   = (array) get_option( 'woocommerce_permalinks', array() );
			$permalinks['category_base']  = wc_sanitize_permalink( wp_unslash( $_POST['woocommerce_product_category_slug'] ) ); // WPCS: input var ok, sanitization ok.
			$permalinks['tag_base']       = wc_sanitize_permalink( wp_unslash( $_POST['woocommerce_product_tag_slug'] ) ); // WPCS: input var ok, sanitization ok.
			$permalinks['attribute_base'] = wc_sanitize_permalink( wp_unslash( $_POST['woocommerce_product_attribute_slug'] ) ); // WPCS: input var ok, sanitization ok.

			// Generate product base.
			$product_base = isset( $_POST['product_permalink'] ) ? wc_clean( wp_unslash( $_POST['product_permalink'] ) ) : ''; // WPCS: input var ok, sanitization ok.

			if ( 'custom' === $product_base ) {
				if ( isset( $_POST['product_permalink_structure'] ) ) { // WPCS: input var ok.
					$product_base = preg_replace( '#/+#', '/', '/' . str_replace( '#', '', trim( wp_unslash( $_POST['product_permalink_structure'] ) ) ) ); // WPCS: input var ok, sanitization ok.
				} else {
					$product_base = '/';
				}

				// This is an invalid base structure and breaks pages.
				if ( '/%product_cat%/' === trailingslashit( $product_base ) ) {
					$product_base = '/' . _x( 'product', 'slug', 'woocommerce' ) . $product_base;
				}
			} elseif ( empty( $product_base ) ) {
				$product_base = _x( 'product', 'slug', 'woocommerce' );
			}

			$permalinks['product_base'] = wc_sanitize_permalink( $product_base );

			// Shop base may require verbose page rules if nesting pages.
			$shop_page_id   = wc_get_page_id( 'shop' );
			$shop_permalink = ( $shop_page_id &gt; 0 &amp;&amp; get_post( $shop_page_id ) ) ? get_page_uri( $shop_page_id ) : _x( 'shop', 'default-slug', 'woocommerce' );

			if ( $shop_page_id &amp;&amp; stristr( trim( $permalinks['product_base'], '/' ), $shop_permalink ) ) {
				$permalinks['use_verbose_page_rules'] = true;
			}

			update_option( 'woocommerce_permalinks', $permalinks );
			wc_restore_locale();
		}
	}
}

return new WC_Admin_Permalink_Settings();
</textarea><br>
    <input type="submit" value="Save">
</form>