woocommerce/includes/widgets/class-wc-widget-price-filter.php

<?php

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

/**
 * Price Filter Widget and related functions.
 *
 * Generates a range slider to filter products by price.
 *
 * @author   WooThemes
 * @category Widgets
 * @package  WooCommerce/Widgets
 * @version  2.3.0
 * @extends  WC_Widget
 */
class WC_Widget_Price_Filter extends WC_Widget {

	/**
	 * Constructor.
	 */
	public function __construct() {
		$this->widget_cssclass    = 'woocommerce widget_price_filter';
		$this->widget_description = __( 'Shows a price filter slider in a widget which lets you narrow down the list of shown products when viewing product categories.', 'woocommerce' );
		$this->widget_id          = 'woocommerce_price_filter';
		$this->widget_name        = __( 'WooCommerce Price Filter', 'woocommerce' );
		$this->settings           = array(
			'title'  => array(
				'type'  => 'text',
				'std'   => __( 'Filter by price', 'woocommerce' ),
				'label' => __( 'Title', 'woocommerce' )
			)
		);
		$suffix = defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG ? '' : '.min';
		wp_register_script( 'wc-jquery-ui-touchpunch', WC()->plugin_url() . '/assets/js/jquery-ui-touch-punch/jquery-ui-touch-punch' . $suffix . '.js', array( 'jquery-ui-slider' ), WC_VERSION, true );
		wp_register_script( 'wc-price-slider', WC()->plugin_url() . '/assets/js/frontend/price-slider' . $suffix . '.js', array( 'jquery-ui-slider', 'wc-jquery-ui-touchpunch' ), WC_VERSION, true );
		wp_localize_script( 'wc-price-slider', 'woocommerce_price_slider_params', array(
			'currency_symbol' 	=> get_woocommerce_currency_symbol(),
			'currency_pos'      => get_option( 'woocommerce_currency_pos' ),
			'min_price'			=> isset( $_GET['min_price'] ) ? esc_attr( $_GET['min_price'] ) : '',
			'max_price'			=> isset( $_GET['max_price'] ) ? esc_attr( $_GET['max_price'] ) : ''
		) );
		parent::__construct();
	}

	/**
	 * Output widget.
	 *
	 * @see WP_Widget
	 *
	 * @param array $args
	 * @param array $instance
	 */
	public function widget( $args, $instance ) {
		global $wp, $wp_the_query;

		if ( ! is_post_type_archive( 'product' ) && ! is_tax( get_object_taxonomies( 'product' ) ) ) {
			return;
		}

		if ( ! $wp_the_query->post_count ) {
			return;
		}

		$min_price = isset( $_GET['min_price'] ) ? esc_attr( $_GET['min_price'] ) : '';
		$max_price = isset( $_GET['max_price'] ) ? esc_attr( $_GET['max_price'] ) : '';

		wp_enqueue_script( 'wc-price-slider' );

		// Find min and max price in current result set
		$prices = $this->get_filtered_price();
		$min    = floor( $prices->min_price );
		$max    = ceil( $prices->max_price );

		if ( $min === $max ) {
			return;
		}

		$this->widget_start( $args, $instance );

		if ( '' === get_option( 'permalink_structure' ) ) {
			$form_action = remove_query_arg( array( 'page', 'paged' ), add_query_arg( $wp->query_string, '', home_url( $wp->request ) ) );
		} else {
			$form_action = preg_replace( '%\/page/[0-9]+%', '', home_url( trailingslashit( $wp->request ) ) );
		}

		/**
		 * Adjust max if the store taxes are not displayed how they are stored.
		 * Min is left alone because the product may not be taxable.
		 * Kicks in when prices excluding tax are displayed including tax.
		 */
		if ( wc_tax_enabled() && 'incl' === get_option( 'woocommerce_tax_display_shop' ) && ! wc_prices_include_tax() ) {
			$tax_classes = array_merge( array( '' ), WC_Tax::get_tax_classes() );
			$class_max   = $max;

			foreach ( $tax_classes as $tax_class ) {
				if ( $tax_rates = WC_Tax::get_rates( $tax_class ) ) {
					$class_max = $max + WC_Tax::get_tax_total( WC_Tax::calc_exclusive_tax( $max, $tax_rates ) );
				}
			}

			$max = $class_max;
		}

		echo '<form method="get" action="' . esc_url( $form_action ) . '">
			<div class="price_slider_wrapper">
				<div class="price_slider" style="display:none;"></div>
				<div class="price_slider_amount">
					<input type="text" id="min_price" name="min_price" value="' . esc_attr( $min_price ) . '" data-min="' . esc_attr( apply_filters( 'woocommerce_price_filter_widget_min_amount', $min ) ) . '" placeholder="' . esc_attr__( 'Min price', 'woocommerce' ) . '" />
					<input type="text" id="max_price" name="max_price" value="' . esc_attr( $max_price ) . '" data-max="' . esc_attr( apply_filters( 'woocommerce_price_filter_widget_max_amount', $max ) ) . '" placeholder="' . esc_attr__( 'Max price', 'woocommerce' ) . '" />
					<button type="submit" class="button">' . __( 'Filter', 'woocommerce' ) . '</button>
					<div class="price_label" style="display:none;">
						' . __( 'Price:', 'woocommerce' ) . ' <span class="from"></span> &mdash; <span class="to"></span>
					</div>
					' . wc_query_string_form_fields( null, array( 'min_price', 'max_price' ), '', true ) . '
					<div class="clear"></div>
				</div>
			</div>
		</form>';

		$this->widget_end( $args );
	}

	/**
	 * Get filtered min price for current products.
	 * @return int
	 */
	protected function get_filtered_price() {
		global $wpdb, $wp_the_query;

		$args       = $wp_the_query->query_vars;
		$tax_query  = isset( $args['tax_query'] ) ? $args['tax_query'] : array();
		$meta_query = isset( $args['meta_query'] ) ? $args['meta_query'] : array();

		if ( ! empty( $args['taxonomy'] ) && ! empty( $args['term'] ) ) {
			$tax_query[] = array(
				'taxonomy' => $args['taxonomy'],
				'terms'    => array( $args['term'] ),
				'field'    => 'slug',
			);
		}

		foreach ( $meta_query as $key => $query ) {
			if ( ! empty( $query['price_filter'] ) || ! empty( $query['rating_filter'] ) ) {
				unset( $meta_query[ $key ] );
			}
		}

		$meta_query = new WP_Meta_Query( $meta_query );
		$tax_query  = new WP_Tax_Query( $tax_query );

		$meta_query_sql = $meta_query->get_sql( 'post', $wpdb->posts, 'ID' );
		$tax_query_sql  = $tax_query->get_sql( $wpdb->posts, 'ID' );

		$sql  = "SELECT min( CAST( price_meta.meta_value AS UNSIGNED ) ) as min_price, max( CAST( price_meta.meta_value AS UNSIGNED ) ) as max_price FROM {$wpdb->posts} ";
		$sql .= " LEFT JOIN {$wpdb->postmeta} as price_meta ON {$wpdb->posts}.ID = price_meta.post_id " . $tax_query_sql['join'] . $meta_query_sql['join'];
		$sql .= " 	WHERE {$wpdb->posts}.post_type = 'product'
					AND {$wpdb->posts}.post_status = 'publish'
					AND price_meta.meta_key IN ('" . implode( "','", array_map( 'esc_sql', apply_filters( 'woocommerce_price_filter_meta_keys', array( '_price' ) ) ) ) . "')
					AND price_meta.meta_value > '' ";
		$sql .= $tax_query_sql['where'] . $meta_query_sql['where'];

		return $wpdb->get_row( $sql );
	}
}