WooCommerce simple widget based on ACF

gistfile1.txt

<?php
defined( 'ABSPATH' ) || exit;

class BikeRide_Simple_Widget extends WC_Widget {

	private $meta_key = '';
	private $meta_prefix  = '_bike_';

	/**
	 * Constructor.
	 */
	public function __construct() {
		$this->widget_cssclass    = 'woocommerce widget_simple';
		// $this->widget_description = __( 'Simple widget.', 'bikeride' );
		$this->widget_id          = 'woocommerce_simple';
		$this->widget_name        = esc_html__( 'Bikeride: Range Filter for number attributes', 'bikeride' );

		add_action( 'pre_get_posts', array( $this, 'pre_get_posts' ), 10, 1 );
		add_filter( 'acf/load_field/name=metadata', array( $this, 'load_choices' ) );
		
		parent::__construct();
	}

	public function widget( $args, $instance ) {
		global $wp;

		if ( ! is_shop() && ! is_product_taxonomy() ) {
			return;
		}

		if ( ! wc()->query->get_main_query()->post_count ) {
			return;
		}

		if ( empty( $this->meta_key ) ) {
			return;
		}

		$ranges = get_field( 'range', 'widget_' . $args['widget_id'] );

		if ( empty( $ranges ) ) {
			return;
		}

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

		$title = get_field( 'title', 'widget_' . $args['widget_id'] );

		if ( $heading = apply_filters( 'widget_title', empty( $title ) ? '' : $title, $instance, $this->id_base ) ) {
			echo $args['before_title'] . $heading . $args['after_title'];
		}

		$query_arg_key = $this->get_query_arg_key();

		$html = '';

		// $queried_object_id = get_queried_object_id();
		// $current_page_url  = get_permalink( $queried_object_id );
		$current_page_url = home_url( add_query_arg( array(), $wp->request ) );

		foreach ( $ranges as $range ) {
			$_from = ( '' === $range['from'] ) ? 'below' : absint( $range['from'] );
			$_to   = ( '' === $range['to'] )   ? 'above' : absint( $range['to'] );

			$url = add_query_arg( array( $query_arg_key => sprintf( '%1$s-%2$s', $_from, $_to ) ), $current_page_url );

			$delimiter = '&nbsp;';

			if ( is_int( $_from ) && is_int( $_to ) ) {
				$delimiter = '&nbsp;&ndash;&nbsp;';
			}

			$format = '<li><a href="%3$s"><span>%1$s</span>%4$s<span>%2$s</span></a></li>';

			if ( ! is_int( $_to ) ) {
				$format = '<li><a href="%3$s"><span>%2$s</span>%4$s<span>%1$s</span></a></li>';
			}

			$html .= sprintf( $format, $_from, $_to, esc_url( $url ), $delimiter );
		}

		if ( ! empty( $html ) ) {
			$html = sprintf( '<ul>%s</ul>', $html );

			echo $html;
		}

		$this->widget_end( $args );
	}

	/**
	 * Undocumented function
	 *
	 * @param [type] $query
	 * @link https://www.advancedcustomfields.com/resources/creating-wp-archive-custom-field-filter/
	 * @return void
	 */
	public function pre_get_posts( $query ) {

		if ( is_admin() ) {
			return;
		}
	
		if ( ! $query->is_main_query() ) {
			return;
		}

		// Get meta query
		$this->meta_key = get_field( 'metadata', 'widget_' . $this->id );
		$query_arg_key = $this->get_query_arg_key();

		if ( empty( $_GET[ $query_arg_key ] ) ) {
			return;
		}

		// Get the value for this filter
		// eg: http://www.website.com/reviews?foobar=xxx-yyy
		$value = explode( '-', $_GET[ $query_arg_key ] );

		// New meta query
		$new_meta_query = array();

		if ( 'below' !== $value[0] ) {
			$new_meta_query[] = array(
				'key'		=> $this->meta_key,
				'value'		=> absint( $value[0] ),
				'compare'	=> '>=',
				'type'		=> 'numeric',
			);
		}

		if ( 'above' !== $value[1] ) {
			$new_meta_query[] = array(
				'key'		=> $this->meta_key,
				'value'		=> absint( $value[1] ),
				'compare'	=> '<=',
				'type'		=> 'numeric',
			);
		}

		if ( 1 > sizeof( $new_meta_query ) ) {
			return;
		}

		$new_meta_query = array_merge( $new_meta_query, array( 'relation' => 'AND' ) );
		$meta_query     = $query->get( 'meta_query' );

		// Update meta query
		$query->set( 'meta_query', array_merge( $meta_query, $new_meta_query ) );
	}

	public function load_choices( $field ) {
		$meta_group_fields = acf_get_fields( 'group_5c1fa9a17c4cf' );

		$field['choices'] = wp_list_pluck( $meta_group_fields, 'label', 'name' );

		return $field;
	}

	public function get_meta_key() {
		return $this->meta_key;
	}

	public function get_meta_prefix() {
		return $this->meta_prefix;
	}

	public function get_query_arg_key() {
		$query_arg_key = explode( $this->get_meta_prefix(), $this->get_meta_key() );

		return $query_arg_key[1];
	}
}

gistfile2.txt

{
    "key": "group_5c1fc4935d525",
    "title": "Simple widget",
    "fields": [
        {
            "key": "field_5c1fc4a5d4281",
            "label": "Title:",
            "name": "title",
            "type": "text",
            "instructions": "",
            "required": 0,
            "conditional_logic": 0,
            "wrapper": {
                "width": "",
                "class": "",
                "id": ""
            },
            "default_value": "",
            "placeholder": "",
            "prepend": "",
            "append": "",
            "maxlength": ""
        },
        {
            "key": "field_5c1ffd6057655",
            "label": "Choose metadata:",
            "name": "metadata",
            "type": "select",
            "instructions": "",
            "required": 0,
            "conditional_logic": 0,
            "wrapper": {
                "width": "",
                "class": "",
                "id": ""
            },
            "choices": [],
            "default_value": [],
            "allow_null": 0,
            "multiple": 0,
            "ui": 0,
            "return_format": "value",
            "ajax": 0,
            "placeholder": ""
        },
        {
            "key": "field_5c1fc4bdcca1d",
            "label": "Range:",
            "name": "range",
            "type": "repeater",
            "instructions": "",
            "required": 0,
            "conditional_logic": 0,
            "wrapper": {
                "width": "",
                "class": "",
                "id": ""
            },
            "collapsed": "",
            "min": 1,
            "max": 0,
            "layout": "table",
            "button_label": "Add new range",
            "sub_fields": [
                {
                    "key": "field_5c1fc50dcca1e",
                    "label": "From",
                    "name": "from",
                    "type": "number",
                    "instructions": "",
                    "required": 0,
                    "conditional_logic": 0,
                    "wrapper": {
                        "width": "",
                        "class": "",
                        "id": ""
                    },
                    "default_value": "",
                    "placeholder": "",
                    "prepend": "",
                    "append": "",
                    "min": 0,
                    "max": "",
                    "step": ""
                },
                {
                    "key": "field_5c1fc52acca1f",
                    "label": "To",
                    "name": "to",
                    "type": "number",
                    "instructions": "",
                    "required": 0,
                    "conditional_logic": 0,
                    "wrapper": {
                        "width": "",
                        "class": "",
                        "id": ""
                    },
                    "default_value": "",
                    "placeholder": "",
                    "prepend": "",
                    "append": "",
                    "min": 1,
                    "max": "",
                    "step": ""
                }
            ]
        }
    ],
    "location": [
        [
            {
                "param": "widget",
                "operator": "==",
                "value": "woocommerce_simple"
            }
        ]
    ],
    "menu_order": 0,
    "position": "normal",
    "style": "default",
    "label_placement": "top",
    "instruction_placement": "label",
    "hide_on_screen": "",
    "active": 1,
    "description": "",
    "modified": 1545600742
}