IBM Developers work has a tutorial on
how to build an RSS reader using AJAX. The amount of code you need to write is scary (and this is not the complete code). Adobe Flex 2 plus a simple Java programming to support DB interaction allows you to achive the same functionality using A LOT LESS coding.Just take a look at this screen:
The Flex 2 code below populates the bottom portion of the screen with financial news based on the selected stock on top ( (it does not work with a DB to store the RSS source so it'd add some 50 lines of Java code ). The data come from the Yahoo! Finance RSS feed. The URL looks as follows:
http://finance.yahoo.com/rss/headline?s=MSFT
The suffix can be MSFT or whatever is selected on top is being passed to the code below.
Flex <mx:HTTPService> object is used through a proxy deployed under Tomcat or any other servlet container.
The entire application code and its description can be found in
this article.
<?xml version="1.0" encoding="utf-8"?>
<mx:Panel xmlns:mx="http://www.adobe.com/2006/mxml"
title="News" width="100%" height="100%" >
<mx:DataGrid id="newsGrid" width="100%" height="100%"
dataProvider="{newsFeed.lastResult.channel.item}" variableRowHeight="true">
<mx:columns>
<mx:DataGridColumn headerText="Date" dataField="pubDate" width="200"/>
<mx:DataGridColumn headerText="Title" dataField="title" wordWrap="true" />
<mx:DataGridColumn headerText="Description" dataField="description" wordWrap="true" />
<mx:DataGridColumn headerText="Link" width="130">
<mx:itemRenderer>
<mx:Component>
<mx:LinkButton label="{data.link}" click="navigateToURL(new URLRequest(data.link), '_blank')"/>
</mx:Component>
</mx:itemRenderer>
</mx:DataGridColumn>
</mx:columns>
</mx:DataGrid>
<mx:HTTPService id="newsFeed" useProxy="true"
destination="YahooFinancialNews" concurrency="last"
resultFormat="e4x" fault="onFault(event)" >
</mx:HTTPService>
<mx:Script>
<![CDATA[
import mx.utils.ObjectProxy;
import mx.rpc.events.*;
public function set security(value:String):void {
this.title = "News: " + value;
newsFeed.send({s:value});
}
private function onFault(event:FaultEvent):void {
mx.controls.Alert.show
(
"Destination:" + event.currentTarget.destination + "\n" +
"Fault code:" + event.fault.faultCode + "\n" +
"Detail:" + event.fault.faultDetail, "News feed failure"
);
}
]]>
</mx:Script>
</mx:Panel>
tags: flex 2 ajax rss reader
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