I’ve written a small example to show how to call REST services from Flex.

See working example: click here

Source code: click here

The sample is source code enabled.
Accessing REST services with Flex is pretty simple. The main work done in the code is done by the following code:

<mx:HTTPService id=”yahoo_image_search”
url=”http://search.yahooapis.com/ImageSearchService/V1/imageSearch”>
<mx:request>
<appid>get your id from yahoo</appid>
<query>{input.text}</query>
</mx:request>
</mx:HTTPService>

Here we are calling the REST API with HTTP Service and passing it two required parameters:
appid - The application ID. See Application IDs for more information.
query - The query to search for. Use + to include terms, - to exclude terms, and put quotes around “exact phrase”.

You can find the complete description of the Yahoo! Image Search API here - http://developer.yahoo.com/search/image/V1/imageSearch.html

The response returned by the API is in XML format:

<ResultSet xmlns:xsi=”http://www.w3.org/2001/XMLSchema-instance” xmlns=”urn:yahoo:srchmi” xsi:schemaLocation=”urn:yahoo:srchmi http://search.yahooapis.com/ImageSearchService/V1/ImageSearchResponse.xsd” totalResultsAvailable=”190145″ totalResultsReturned=”2″ firstResultPosition=”1″>
<Result>
<Title>Madonna photo Madonna 6200315</Title>
<Summary />
<Url>
http://www.poster.net/madonna/madonna-photo-madonna-6200315.jpg</Url>

Hence, to access the main results we need to access the <Result> node inside of <ResultSet>, which is pretty state forward with our Datagrid.