some question about REST data source

I want to implement a REST data source for client-side data integration.
I just study show case sample of REST http://www.smartclient.com/smartgwt/showcase/#featured_restfulds, but with some confusion.

when I click “Add new Country” button, the http message is as below:
<request> <data> <isc_RestfulDataSourceSample$1_0> <countryCode>US</countryCode> <countryName>Edited Value</countryName> <capital>Edited Value</capital> <continent>Edited Value</continent> </isc_RestfulDataSourceSample$1_0> </data> <dataSource>isc_RestfulDataSourceSample$1_0</dataSource> <operationType>update</operationType> <componentId>isc_ListGrid_0</componentId> <oldValues></oldValues> </request>

Three question here:

  1. I want to add some extra control info into this xml, for example <feed>xxx</feed>, how?
  2. the xml sent by smartgwt client include a special character “$”(isc_RestfulDataSourceSample$1_0), so the xml become a not well-formed xml, anyone has idea about this.
  3. how to override transformRequest and transformResponse, anyone has such expirence can share some sample code?

Thanks very much!

after change some code, now the response look as below, which is well-formed xml now

<request>
<data>
<isc_RestDataSource_0>
<countryCode>A1</countryCode>
<countryName>New Value</countryName>
<capital>New Value</capital>
<continent>New Value</continent>
</isc_RestDataSource_0>
</data>
<dataSource>isc_RestDataSource_0</dataSource>
<operationType>add</operationType>
<componentId>isc_ListGrid_0</componentId>
<oldValues></oldValues>
</request>
Source
<request> <data> <isc_RestDataSource_0> <countryCode>A1</countryCode> <countryName>New Value</countryName> <capital>New Value</capital> <continent>New Value</continent> </isc_RestDataSource_0> </data> <dataSource>isc_RestDataSource_0</dataSource> <operationType>add</operationType> <componentId>isc_ListGrid_0</componentId> <oldValues></oldValues> </request>

and still look forward the answer for other two question, thanks!

Could anyone give some sample about how to override transformRequest and transformResponse, thanks!