pre_get_posts Custom post filter by custom fields

• Webic

• January 10, 2019 at 6:31 am

Hi,
I have created a custom post type Car and some custom field.
Now I tried to make filterable cars in archive page, but when I checked one of value of field all cars hide and checkbox filter disappear… I don’t understand why…
This is code in functions.php

// array of filters (field key => field name)
$GLOBALS['my_query_filters'] = array( 
	'carburante' => 'carburante'
);

add_action('pre_get_posts', 'filter_car_posts', 10, 1);

function filter_car_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->is_main_query() ) return;

    if( ! is_post_type_archive( 'car' ) ) return;
    
    
     // CITY/TYPE/DATE filters
    // 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 ]);
            
        // append meta query
    	$meta_query[] = array(
            'key'		=> $name,
            'value'		=> $value,
            'compare'	=> 'IN',  
        );
	}
    
	// update meta query
	$query->set( 'meta_query', $meta_query);
    $query->set( 'posts_per_page', '20');
    
}

And this is code for filtering option

<?php foreach( $GLOBALS['my_query_filters'] as $key => $name ): 

					// get the field's settings without attempting to load a value
					$field = get_field_object($key, false, false);

					// set value if available
					if( isset($_GET[ $name ]) ) {
						$field['value'] = explode(',', $_GET[ $name ]);
					}
					// create filter
					?>
					<div class="filter" data-filter="<?php echo $name; ?>">
						<?php create_field( $field ); ?>
					</div>

				<?php endforeach; ?>
				</div>

				<script type="text/javascript">
				(function($) {
					// change
					$('#archive-filters').on('change', 'input[type="checkbox"]', function(){
						// vars
						var url = '<?php echo home_url('car'); ?>';
							args = {};
						// loop over filters
						$('#archive-filters .filter').each(function(){
							// vars
							var filter = $(this).data('filter'),
								vals = [];
							// find checked inputs
							$(this).find('input:checked').each(function(){
								vals.push( $(this).val() );
							});
							// append to args
							args[ filter ] = vals.join(',');
						});
						// update url
						url += '?';
						// loop over args
						$.each(args, function( name, value ){
							url += name + '=' + value + '&';
						});
						// remove last &
						url = url.slice(0, -1);
						// reload page
						window.location.replace( url );
					});
				})(jQuery);
				</script>