protected function mapping_form() {
		check_admin_referer( 'woocommerce-csv-importer' );
		$args = array(
			'lines'     => 1,
			'delimiter' => $this->delimiter,
		);

		$importer     = self::get_importer( $this->file, $args );
		$headers      = $importer->get_raw_keys();
		$mapped_items = $this->auto_map_columns( $headers );
		$sample       = current( $importer->get_raw_data() );

		if ( empty( $sample ) ) {
			$this->add_error(
				__( 'The file is empty or using a different encoding than UTF-8, please try again with a new file.', 'woocommerce' ),
				array(
					array(
						'url'   => admin_url( 'edit.php?post_type=product&page=product_importer' ),
						'label' => __( 'Upload a new file', 'woocommerce' ),
					),
				)
			);

			// Force output the errors in the same page.
			$this->output_errors();
			return;
		}

		include_once dirname( __FILE__ ) . '/views/html-csv-import-mapping.php';
	}