+
+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.
Please note: This example will not function on iOS devices due to the usage of Flash as the cross-domain transport. This example may not work on older Android devices, as well.
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+
+Exploring the Code for This Example
+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:'../../build/io-xdr/io.swf' //Relative path to the .swf file from the current page.
+};
+Y.io.transport(xdrConfig);
+
+
+Callback Object and the Weather RSS
+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");
+}
+
+
+Assemble the Querystring and Initiate the Transaction
+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:
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+
- p — location as U.S. Zip Code or Location ID +
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 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");
+});
+
+
+Full Script Source
+ +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:'../../build/io-xdr/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>
+
+