[flexcoders] [lcds] create custom assembler to get XML data

[tit0uill3]

Hello group !

I would like to create my own custom assembler to retrieve some data
from database in xml format. I don't know if it's the better way to do
that, but I have some hibernate assemblers called in my application,
and don't want to complexify with other http or rpc services... Tell
me if I'm on the wrong way :)p

So I create an assembler like this, just for tests : 

/**
 * 
 */
package com.neolinkup.app.vo;


import flex.data.assemblers.AbstractAssembler;
import flex.messaging.io.ArrayCollection;

import java.io.ByteArrayInputStream;
import java.io.IOException;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.ParserConfigurationException;

import org.xml.sax.InputSource;
import org.xml.sax.SAXException;


/**
 * @author titouille
 *
 */
public class RoomAssembler extends AbstractAssembler
{
        public ArrayCollection fill()
        {
                String s = "<rooms>" +
                                                "<cinema id='1' label='cinema 
1'>" +
                                                        "<room roomid='1' 
label='room 1' />" +
                                                        "<room roomid='2' 
label='room 2' />" +
                                                "</cinema>" +
                                        "</rooms>";

                try 
                {
                        DocumentBuilderFactory docBuilderFactory =
DocumentBuilderFactory.newInstance();
                        DocumentBuilder docBuilder = 
docBuilderFactory.newDocumentBuilder();
                
                        ArrayCollection a = new ArrayCollection();
                        a.add( docBuilder.parse( new InputSource( new 
ByteArrayInputStream(
s.getBytes() ) ) ) );
                        return a;
                }
                catch( ParserConfigurationException pce ) 
                {
                        System.out.println( "ERROR - 
ParserConfigurationException:
getXmlDocument - " + pce.getMessage() );
                        return null;
                }
                catch( SAXException saxe ) 
                {
                        System.out.println( "ERROR - SAXException: 
getXmlDocument - " +
saxe.getMessage() );
                        return null;
                }
                catch( IOException ioe )
                {
                        System.out.println( "ERROR - IOException: 
getXmlDocument - " +
ioe.getMessage() );
                        return null;
                }
        }
}

and my destination : 

        <destination id="roomvo.hibernate">
                <adapter ref="java-dao" />
                <properties>
                        <source>com.neolinkup.app.vo.RoomAssembler</source>
                        <scope>application</scope>
                        <metadata>
                                <identity property="roomid"/>
                        </metadata>
                        <network>
                                <session-timeout>20</session-timeout>
                                <paging enabled="false" pageSize="10" />
                                <throttle-inbound policy="ERROR" 
max-frequency="500"/>
                                <throttle-outbound policy="REPLACE" 
max-frequency="500"/>
                        </network>
                        <server>
                                <fill-method>
                                        <name>fill</name>
                                </fill-method>
                        </server>
                </properties>
        </destination>


And I try with a simple mxml application with :

ds = new DataService( "roomvo.hibernate" );
list = new ArrayCollection();
                                
s.addEventListener( DataServiceFaultEvent.FAULT, this._handleFault );
s.addEventListener( DataConflictEvent.CONFLICT, this._handleConflict );
s.addEventListener(ResultEvent.RESULT, this._handleResult );
s.fill( list );

But Flex return to me an error like this : 

ArgumentError: Items must support IManaged. See [Managed] for more
information: object: <rooms>
<cinema id="1" label="cinema 1">
<room roomid="1" label="room 1"/>
<room roomid="2" label="room 2"/>
</cinema>
</rooms> with referencedIds []
at
mx.data::ConcreteDataService/http://www.adobe.com/2006/flex/mx/internal::normalize()[C:\depot\flex\branches\enterprise_bridgeman\frameworks\mx\data\ConcreteDataService.as:2595]
at
mx.data::DataList/http://www.adobe.com/2006/flex/mx/internal::processSequence()[C:\depot\flex\branches\enterprise_bridgeman\frameworks\mx\data\DataList.as:1597]
at
mx.data::DataList/http://www.adobe.com/2006/flex/mx/internal::processSequenceResult()[C:\depot\flex\branches\enterprise_bridgeman\frameworks\mx\data\DataList.as:1788]
at
DataListRequestResponder/result()[C:\depot\flex\branches\enterprise_bridgeman\frameworks\mx\data\ConcreteDataService.as:5857]
at
mx.rpc::AsyncRequest/acknowledge()[E:\dev\3.0.x\frameworks\projects\rpc\src\mx\rpc\AsyncRequest.as:74]
at
NetConnectionMessageResponder/resultHandler()[E:\dev\3.0.x\frameworks\projects\rpc\src\mx\messaging\channels\NetConnectionChannel.as:469]
at
mx.messaging::MessageResponder/result()[E:\dev\3.0.x\frameworks\projects\rpc\src\mx\messaging\MessageResponder.as:199]


If I try to return a dom document instead of an arrayCollection, lcds
return to me a casting error...

Any suggestion about how to get some "read-only" XML data to fill a
tree with complex hierarchical data... I need java to get data from DB
and format it as XML, but don't know the better way to do it... If
anyone has a way or some informations, tutorials, etc... I'm very
interested.

Thanks in advance.


Thierry aka titouille