This example demonstrates how to use IO to make a cross-domain request to http://weather.yahooapis.com/forecastrss. To try out the example, fill in your five-digit US zip code, or Location ID.
Notes:
io.swf file. Necessary source files for compilation are available in the yui3-swfs repository.Create a YUI instance, using IO, for this example:
//Create a YUI instance including support for cross-domain IO:
YUI().use("io-xdr", "node", function(Y) {
// Y is the YUI instance.
// The rest of the following code is encapsulated in this
// anonymous function.
} );
//Configure the cross-domain transport:
var xdrConfig = {
id:'flash', //We'll reference this id in the xdr configuration of our transaction.
src:'io.swf' //Relative path to the .swf file from the current page.
};
Y.io.transport(xdrConfig);
Yahoo! Weather RSS will return an XML document if the transaction is successful. The following success callback handlers is used to process the response.
//Define a function to handle a successful response from
//Yahoo! Weather. The success handler will find the response
//object in its second argument:
function successHandler(id, o){
Y.log("Success handler called; handler will parse the retrieved XML and insert into DOM.", "info", "example");
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;
div.set("innerHTML", "<p>" + oTitle + "</p>" + "<p>" + oDateTime + "</p>" + descriptionNode);
Y.log("Success handler is complete.", "info", "example");
}
The Yahoo! Weather RSS feed requires a simple HTTP GET request with a base URL and a querystring containing the required information as a name-value pair. In this example, we will use the following parameter:
The following are some example Location IDs (do not include the city name):
For more details on the Yahoo! 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 creates a querystring:
//When the Get RSS button is clicked, this function will fire
//and compose/dispatch the IO request:
function getModule(){
//Get the input value:
var iZip = Y.one('#zip').get("value");
//Create a querystring from the input value:
var queryString = encodeURI('?p=' + iZip);
//The Yahoo! Weather feed.
var entryPoint = 'http://weather.yahooapis.com/forecastrss';
//Compile the full URI for the request:
var sUrl = entryPoint + queryString;
Y.log("Submitting request; zip code: " + iZip, "info", "example");
//Make the reqeust:
var request = Y.io(sUrl, {
method:"GET",
on:
{
success:successHandler,
failure:failureHandler
}
}
);
}
//Add the click handler to the Get Weather RSS button as soon
//as the Flash transport has loaded, indicated by the firing
//of event "io:xdrReady".
Y.on('io:xdrReady', function() {
var btn = Y.one("#getWeather");
btn.set("disabled", false);
//Use the Event Utility to wire the Get RSS button
//to the getModule function.
Y.on("click", getModule, "#getWeather");
});
Here is the full JavaScript source for this example:
<form id="wForm">
<fieldset>
<label>Zip Code or Location ID</label> <input type="text" id="zip" value="94089">
<p>Please enter a U.S. Zip Code or a Location ID to get the current temperature. The default is Zip Code 94089 for Sunnyvale, California; its location ID is: USCA1116.</p>
</fieldset>
<div id="weatherModule">
<li>Weather RSS data will appear here.</li>
</div>
<input type="button" value="Get Weather RSS" id="getWeather" disabled="disabled">
</form>
<script language="javascript">
YUI({ filter:'raw' }).use("io-xdr", "node",
function(Y) {
//Get a Node reference to the div we'll use for displaying
//results:
var div = Y.one('#weatherModule');
//Configure the cross-domain transport:
var xdrConfig = {
id:'flash', //We'll reference this id in the xdr configuration of our transaction.
src:'io.swf' //Relative path to the .swf file from the current page.
};
Y.io.transport(xdrConfig);
//Define a function to handle a successful response from
//Yahoo! Weather. The success handler will find the response
//object in its second argument:
function successHandler(id, o){
Y.log("Success handler called; handler will parse the retrieved XML and insert into DOM.", "info", "example");
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;
div.set("innerHTML", "<p>" + oTitle + "</p>" + "<p>" + oDateTime + "</p>" + descriptionNode);
Y.log("Success handler is complete.", "info", "example");
}
//Provide a function that can help debug failed
//requests:
function failureHandler(id, o){
Y.log("Failure handler called; http status: " + o.status, "info", "example");
div.set("innerHTML", o.status + " " + o.statusText);
}
//When the Get RSS button is clicked, this function will fire
//and compose/dispatch the IO request:
function getModule(){
//Get the input value:
var iZip = Y.one('#zip').get("value");
//Create a querystring from the input value:
var queryString = encodeURI('?p=' + iZip);
//The Yahoo! Weather feed.
var entryPoint = 'http://weather.yahooapis.com/forecastrss';
//Compile the full URI for the request:
var sUrl = entryPoint + queryString;
Y.log("Submitting request; zip code: " + iZip, "info", "example");
//Make the request:
var request = Y.io(sUrl, {
method:"GET",
xdr: {
use:'flash', //This is the xdrConfig id we referenced above.
dataType:'xml' //Indicate the data are XML, not string.
},
on:
{
success:successHandler,
failure:failureHandler
}
}
);
}
//Add the click handler to the Get Weather RSS button as soon
//as the Flash transport has loaded:
Y.on('io:xdrReady', function() {
var btn = Y.one("#getWeather");
btn.set("disabled", false);
//Use the Event Utility to wire the Get RSS button
//to the getModule function.
Y.on("click", getModule, "#getWeather");
});
Y.log("When you retrieve weather RSS data, relevant steps in the process will be reported here in the logger/console.", "info", "example");
}
);
</script>