Retrieving a Y! Weather RSS Feed

This example demonstrates how to use the Connection Manager and a PHP proxy -- to work around XMLHttpRequest's same-domain policy — to retrieve an XML document from http://xml.weather.yahoo.com/forecastrss.

Source file and dependencies

Load the YAHOO namespace and connection manager source file

Callback Object and the Weather RSS

Yahoo! Weather RSS will return an XML document if the transaction is successful. The following callback object with success and failure handlers is used to process the response.

// This is the response display container
var div = document.getElementById('weatherModule');
// This is a reference to the HTML form.
var oForm = document.getElementById('wForm');

/*
 * This method will traverse the response XML document and build a
 * simple HTML module comprised of data from the following tags:
 *
 * Data in the first <title> tag in the document.
 * Data in the first <lastBuildDate> tag in the document.
 * HTML from the second <description> tag in the document.
 *
 */
function successHandler(o){
	var root = o.responseXML.documentElement;
	var oTitle = root.getElementsByTagName('description')[0].firstChild.nodeValue;
	var oDateTime = root.getElementsByTagName('lastBuildDate')[0].firstChild.nodeValue;
	var descriptionNode = root.getElementsByTagName('description')[1].firstChild.nodeValue;

// Format and display results in the response container.
	div.innerHTML = "<p>" + oTitle + "</p>" + "<p>" + oDateTime + "</p>" + descriptionNode;
}

/*
 *
 * This is a simple failure handler that will display
 * the HTTP status code and status message if the resource
 * returns a non-2xx code.
 *
 */
function failureHandler(o){
	div.innerHTML = o.status + " " + o.statusText;
}

Assemble the Querystring and Initiate the Transaction

The Yahoo! Weather RSS feed requires a simple HTTP GET request, with a base URL and a parameters querystring. In this example, we will use the following parameters:

p - location as U.S. Zip Code or Location ID
u - temperature units

The following are some example location IDs (do not include the city name):

Beijing: CHXX0008
Helsinki: FIXX0002
London: UKXX0085
Moscow: RSXX0063
Munich: GMXX0087
Paris: FRXX0076
Riyadh: SAXX0017
Tokyo: JAXX0085

For more details on the Y! Weather RSS feed and other location IDs, please visit http://developer.yahoo.com/weather/index.html.

Function getModule retrieves the input values for location and temperature and creates a querystring.

Proxy and Response

Once weather.php receives the querystring, it will construct and send an HTTP GET using CURL to retrieve the results from the Yahoo! Weather RSS feed. This allows the transaction to succeed while working around XMLHttpRequest's security policy.