To enable 'price from' and 'price to' search for wordpress [WP Property Plugin](https://usabilitydynamics.com/products/wp-property/forum/topic/price-range-search/)

functions.php

/**
 * Rename these to the form input names you are going to use. 
 * When you create a new attribute in Properties->Settings->Developer
 * the form input name will appear greyed out under the attribute name
 */
define('SPRP_SEARCH_FROM_KEY', 'price_from_per_month');
define('SPRP_SEARCH_TO_KEY', 'price_to_per_month');

function parse_search(){

  //vars
  if(@$_REQUEST['wpp_search'][SPRP_SEARCH_FROM_KEY])
    $wpp_search = $_REQUEST['wpp_search'];
  else
    $wpp_search = $_POST['wpp_search'];
  $from = $wpp_search[SPRP_SEARCH_FROM_KEY];
  $to = $wpp_search[SPRP_SEARCH_TO_KEY];

  //set price range
  if(
    isset($wpp_search[SPRP_SEARCH_FROM_KEY]) &&
    isset($wpp_search[SPRP_SEARCH_TO_KEY])
  ){
    $_POST['wpp_search']['price'] = "{$from} - {$to}";
    
    //all
    if( $_POST['wpp_search']['price']=="-1 - -1" )
      $price = "-1";

    //any min
    if( $from=='-1' )
      $price = "0 - {$to}";
    
    //reset price vars
    $_POST['wpp_search']['price'] = $price;
    $_REQUEST['wpp_search']['price'] = $price;

    //any max
    if( $to=='-1' ){
      $price = "{$from} - -1";
      $_POST['wpp_search']['price'] = array();
      $_REQUEST['wpp_search']['price'] = array();
      $_POST['wpp_search']['price']['min'] = $from;
      $_REQUEST['wpp_search']['price']['min'] = $from;
    }

    //between min and max
    if( $to!='-1' && $from!='-1'){
      $_POST['wpp_search']['price'] = "{$from} - {$to}";
      $_REQUEST['wpp_search']['price'] = "{$from} - {$to}";
    }
  }

  //unset custom form input values
  if(@$_REQUEST['wpp_search'][SPRP_SEARCH_FROM_KEY]){
    unset($_REQUEST['wpp_search'][SPRP_SEARCH_FROM_KEY]);
    unset($_REQUEST['wpp_search'][SPRP_SEARCH_TO_KEY]);
  }else{
    unset($_POST['wpp_search'][SPRP_SEARCH_FROM_KEY]);
    unset($_POST['wpp_search'][SPRP_SEARCH_TO_KEY]);
  }
}
parse_search();

Thanks Daithi, where could I call the function from in another theme, if you would like to tell it?