Plugin per WordPress per creare filtri per prodotti di Woocommerce con custom field, genera uno short code.

book-filter.php

<?php
/*
Plugin Name: Book Filter
Description: Crea uno short code per applicare i filtri alla pagina Biblioteca
Version: 1.0
*/

/* Includo js in wordpress */

function enqueue_scripts(){
   
                // wp_enqueue_script('vue', 'https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js', [], '2.5.17');
                 wp_enqueue_script('bookfilter', plugin_dir_url( __FILE__ ) . 'bookfilter.js', [], '1.0', true);
                 wp_enqueue_script('moment', 'https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.10.6/moment.min.js', [], '2.10.6');
        
                 wp_enqueue_script('bootstrap-datepicke', 'https://cdnjs.cloudflare.com/ajax/libs/bootstrap-datepicker/1.7.1/js/bootstrap-datepicker.min.js', [], '1.7.1');
                 wp_enqueue_style( 'bootstrap-datepicker-style', 'https://cdnjs.cloudflare.com/ajax/libs/bootstrap-datepicker/1.9.0/css/bootstrap-datepicker.css' );
                
                 
 }
 add_action( 'wp_enqueue_scripts', 'enqueue_scripts', 20 );


function handle_shortcode() {
    $filtri='';
    $filtri .= '<div id="archive-filters">';
    foreach( $GLOBALS["my_query_filters"] as $key => $name ): 
     $field = get_field_object($key, false, false);
      if( isset($_GET[ $name ]) ) {
       $field["value"] = $_GET[ $name ];
      }
    

    if ($name != 'datauscita'){
        $filtri .='<label class="filter-lable" for="'.$name.'">'.$name.'</label>
        <input type="'.$name.'" class="form-control filter" id="'.$name.'" data-filter="'.$name.'" placeholder="'.$name.'" value="'.$field["value"].'">';
    }
    
    endforeach;

    $filtri .='<label class="filter-lable" for="datauscita">Data Uscita</label>
    <div class="date">
        <input type="text" class="form-control filter" data-filter="datauscita">
        <div class="input-group-addon close-button">
            <span class="glyphicon glyphicon-th"></span>
        </div>
    </div>';

    $filtri .='<button onclick="oraFiltra()" type="submit" class="btn btn-primary">Submit</button>';
    $filtri .='<button onclick="clearFiltri()" type="clear" class="btn btn-secondary">Clear</button>';
    $filtri .='</div>';

    return $filtri;
}
add_shortcode('bookFilter', 'handle_shortcode');

/********************************************************** */
// Hook per applicare i Filtri nella Meta Query in Prodotti 
/********************************************************** */



// array of filters (field key => field name)
$GLOBALS['my_query_filters'] = array( 
    'field_1'	=> 'autore',
	'field_2'	=> 'genere', 
    'field_3'	=> 'editore',
    'field_4'	=> 'datauscita',
    'field_5'	=> 'pagine',
    'field_6'	=> 'ISBN'
);

// action
add_action('pre_get_posts', 'my_pre_get_posts', 10, 1);

function my_pre_get_posts( $query ) {
	
	// bail early if is in admin
	if( is_admin() ) return;
	
	
	// bail early if not main query
	// - allows custom code / plugins to continue working
	
   
    if($query->query_vars['post_type'] == 'product'){
        // get meta query
            $meta_query =(array) $query->get('meta_query');

            
            // loop over filters
            foreach( $GLOBALS['my_query_filters'] as $key => $name ) {
                
                // continue if not found in url
                if( empty($_GET[ $name ]) ) {
                    
                    continue;
                    
                }
                
                
                // get the value for this filter
                // eg: http://www.website.com/events?city=melbourne,sydney
                $value = explode(',', $_GET[ $name ]);
                
                if ($name == 'datauscita'){
                    
                    $format = "d/m/Y";
                    $dateobj = DateTime::createFromFormat($format, $value[0]);
 
                    $value = $dateobj->format('Ymd');
                }
                // append meta query
                $meta_query[] = array(
                    'key'		=> $name,
                    'value'		=> $value,
                    'compare'	=> 'IN',
                );
                
            }  
               

            // update meta query
            $query->set('meta_query', $meta_query);
            
    }
	
	
}

bookfilter.js

// Applica i filtri 
function oraFiltra(){

                // vars
                var url      = window.location.origin;
                args = {};
              
                // loop over filters
                jQuery('#archive-filters .filter').each(function(){
                    
                    // vars
                    var filter = jQuery(this).data('filter');
    
            
                        vals = jQuery(this).val();
            
                    // append to args
                    args[ filter ] = vals;
                    
                });

                // update url
                url += '?';

                // loop over args
                jQuery.each(args, function( name, value ){
                    
                    url += name + '=' + value + '&';
                    
                });
 
                // remove last &
                url = url.slice(0, -1);

                // reload page
                window.location.replace( url );
                
        

    }
 
// Azzera tutti i filtri e ricarica la pagina

function clearFiltri() {  

    var url  = window.location.origin;
    // reload page
    window.location.replace( url );
}

//datapiker

 /* function getUrlParameter(sParam) {
    var sPageURL = window.location.search.substring(1),
        sURLVariables = sPageURL.split('&'),
        sParameterName,
        i;

    for (i = 0; i < sURLVariables.length; i++) {
        sParameterName = sURLVariables[i].split('=');

        if (sParameterName[0] === sParam) {
            return sParameterName[1] === undefined ? true : decodeURIComponent(sParameterName[1]);
        }
    }
}; */



jQuery( document ).ready(function() {


    jQuery('.date').datepicker({
        format: 'dd/mm/yyyy',
        autoclose: true,
    });

  // Unbind default events
  
  jQuery('.close-button').unbind();
  
  // Per far chiudere e riaprire il Datepicker
  
  jQuery('.close-button').click(function() {
    if (jQuery('.datepicker').is(":visible")) {
        jQuery('.date').datepicker('hide');
    } else {
        jQuery('.date').datepicker('show');
    }
  });
    
});