weather.php

<?php

$weather_api_url = "http://weather.yahooapis.com/forecastrss?p=";
$weather_api_ns = "http://xml.weather.yahoo.com/ns/rss/1.0";

function handle_digits($digits) {
  $cleandigits = str_replace(array("#", "*"), "", $digits);
  $maxdigits = substr($cleandigits, 0, 5);
  $xml = fetch_data_for_zip($maxdigits);
  list($city, $region, $text, $temp) = parse_xml($xml);

  $message = "It is currently $temp degrees Fahrenheit and $text in $city, $region";
  saymessage($message);
}

function parse_xml($xml) {
  $dom = new DOMDocument();
  $dom->loadXML($xml);
  $conditions = $dom->getElementsbyTagNameNS("http://xml.weather.yahoo.com/ns/rss/1.0", "condition")->item(0);
  $location = $dom->getElementsbyTagNameNS("http://xml.weather.yahoo.com/ns/rss/1.0", "location")->item(0);
  return array($location->getAttribute("city"),
               $location->getAttribute("region"),
               $conditions->getAttribute("text"),
               $conditions->getAttribute("temp"));
}

function fetch_data_for_zip($zip) {
  $url = "http://weather.yahooapis.com/forecastrss?p=$zip";

  $options = array(
    'http' => array(
        'method'  => 'GET',
        'content' => $url,
        'header'  => "Content-Type: application/xml\r\n"
    ),
  );
  $context  = stream_context_create($options);
  $result = file_get_contents($url, false, $context);
  return $result;
}

function saymessage($msg = "An error occurred", $redirect = NULL) {
  header('Content-Type: application/xml');

  $xmlDoc = new DOMDocument("1.0", "UTF-8");
  $response = $xmlDoc->appendChild($xmlDoc->createElement("Response"));
  $response->appendChild($xmlDoc->createElement("Say", $msg));
  if ($redirect) {
    $response->appendChild($xmlDoc->createElement("Redirect", $redirect));
  }
  $xmlDoc->formatOutput = true;
  echo $xmlDoc->saveXML();
}

function saygreeting() {
  header('Content-Type: application/xml');
  $self = $_SERVER['PHP_SELF'];

  $xmlDoc = new DOMDocument("1.0", "UTF-8");
  $response = $xmlDoc->appendChild($xmlDoc->createElement("Response"));
  $gather = $response->appendChild($xmlDoc->createElement("Gather"));
  $gather->appendChild($xmlDoc->createAttribute("method"))->appendChild($xmlDoc->createTextNode("POST"));
  $gather->appendChild($xmlDoc->createAttribute("numDigits"))->appendChild($xmlDoc->createTextNode("5"));
  $gather->appendChild($xmlDoc->createAttribute("action"))->appendChild($xmlDoc->createTextNode($self));
  $gather->appendChild($xmlDoc->createElement("Play", "greeting.wav"));
  $gather->appendChild($xmlDoc->createElement("Say", "Please enter your 5 digit zipcode to hear the weather."));
  $xmlDoc->formatOutput = true;
  echo $xmlDoc->saveXML();
}

if (isset($_REQUEST['Digits'])) {
  handle_digits($_REQUEST['Digits']);
} else {
  saygreeting();
}
?>