function currency_api_convert in Currency 5

Same name and namespace in other branches

1. 6 currency_api/currency_api.module \currency_api_convert()
2. 7 currency_api/currency_api.module \currency_api_convert()

Currency exchange rate API function

This function converts two currencies using exchange rates from Yahoo Finance. The currency codes are standard ISO 3-letter codes, and you can find the details here: http://www.oanda.com/site/help/iso_code.shtml

Here is an example on how to use it:

$from = 'CAD'; $to = 'USD'; $amt = 20; $ret = currency_exchange($from, $to, $amt); if ($ret['status'] == FALSE) { drupal_set_message(t('An error occured: '). $ret['message']); } else { print $amt .' '. $from .' = '. $ret['value']; }

Parameters

$currency_from: Currency to convert from

$currency_to: Currency to convert to

$amount: Option amount to convert. If not supplied, 1 is assumed.

Return value

$result An associative array that contains the following: $result['status'] TRUE or FALSE $result['message']'success' when status is TRUE, otherwise, contains a descriptive error text The following items are only returned when status is TRUE $result['value'] $amount * exchange rate of $currency_from into $currency_to $result['rate] Exchange rate of $currency_from into $currency_to $result['date'] Date of the last update to the rates (Format is "m/d/yyyy") $result['time'] Time of the last update to the rates (Format is "h:mmpm")

1 call to currency_api_convert()

currency_form_submit in ./currency.module

File

currency_api/currency_api.module, line 95

Code

function currency_api_convert($currency_from, $currency_to, $amount = 1) {
  $currency_array = array(
    's' => 'Currencies',
    'l1' => 'Last',
    'd1' => 'Date',
    't1' => 'Time',
  );
  $result = array();
  $result['status'] = FALSE;
  $result['message'] = NULL;
  $result['value'] = 0;
  $result['rate'] = 1.0;
  $result['date'] = NULL;
  $result['time'] = NULL;
  $from = strtoupper($currency_from);
  $to = strtoupper($currency_to);
  if ($from == $to) {
    return array(
      'status' => TRUE,
      'message' => 'success',
      'value' => $amount,
      'rate' => 1.0,
      'date' => date('n/j/Y'),
      'time' => date('g:ia'),
    );
  }

  // load cached rate, if exists
  $cached = currency_api_load($record, $currency_from, $currency_to);
  if (!$record) {

    // cached rate not found, go get it
    $url = 'http://download.finance.yahoo.com/d/quotes.csv?e=.csv&f=' . currency_api_get_fields($currency_array) . '&s=' . $from . $to . '=X';

    // Validate the passed currency codes, to make sure they are valid
    if (FALSE == currency_api_get_desc($from)) {
      $msg = "currency: Invalid currency_from={$from}";
      _log_to_watchdog($msg, WATCHDOG_ERROR);
      $result['message'] = $msg;
      $result['status'] = FALSE;
    }
    if (FALSE == currency_api_get_desc($to)) {
      $msg = "currency: Invalid currency_to={$to}";
      _log_to_watchdog($msg, WATCHDOG_ERROR);
      return FALSE;
      $result['message'] = $msg;
      $result['status'] = FALSE;
    }
    if (!is_numeric($amount)) {
      $msg = "currency: Invalid amount={$amount}";
      _log_to_watchdog($msg, WATCHDOG_ERROR);
      $result['message'] = $msg;
      $result['status'] = FALSE;
    }
    $http_result = drupal_http_request($url);
    if (isset($http_result->error)) {
      $msg = t('currency: drupal_http_request error: @error', array(
        '@error' => $http_result->error,
      ));
      _log_to_watchdog($msg, WATCHDOG_ERROR);
      return FALSE;
    }
    if ($http_result->code != 200) {
      $msg = t('currency: drupal_http_request code: @code', array(
        '@code' => $http_result->code,
      ));
      _log_to_watchdog($msg, WATCHDOG_ERROR);
      return FALSE;
    }
    $record = $http_result->data;
  }
  if (!$record) {
    $msg = 'currency: cannot contact Yahoo Finance host';
    _log_to_watchdog($msg, WATCHDOG_ERROR);
    $result['status'] = FALSE;
    $result['message'] = $msg;
  }
  $currency_data = explode(',', $record);
  $rate = $currency_data[1];
  $date = $currency_data[2];
  $time = $currency_data[3];

  // Calculate the result
  $value = $amount * $rate;

  // Log it
  _log_to_watchdog("currency: {$amount} {$from} = {$value} {$to}", WATCHDOG_NOTICE);

  // Got what we need
  $result['value'] = $value;
  $result['rate'] = $rate;
  $result['date'] = $date;
  $result['time'] = $time;
  $result['status'] = TRUE;
  $result['message'] = 'success';
  if (!$cached && variable_get('currency_api_fetch', UPDATE_FREQUENCY)) {

    // cache rate does not exist, save it
    currency_api_save($currency_from, $currency_to, $rate);
  }
  return $result;
}