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https://issues.apache.org/jira/browse/OLINGO-1034?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=15661494#comment-15661494
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Santosh kumar edited comment on OLINGO-1034 at 11/13/16 1:39 PM:
-
Hi [~mirbo],
Sorry for delay in response.
PFA Git Diff File
[file:///C:/Users/I324363/git/olingo-odata-callback/olingo-odata2/olingo-odata2.diff]
for the PoC I did on this topic.
The patch includes changes only for OData Read call back. Few points to note:
# Instead of having a separate call back for CRUD operations (for before
execution only),The {{handle}} method of {{ODataEntityBeforeReadCallback}}
class can be used instead. This is because it accepts Parameter of Type
{{org.apache.olingo.odata2.core.uri.UriInfoImpl}} which is top level parameter
before corresponding UriInfo is prepared based on the Operation type.
# We still need to figure out a way to pass EntityManager to client code in the
callback method. This is required if the client prefers to make any backend
call. For example, while persisting SalesOrder, the call back client code may
want to update SalesOrderItem table based on SalesOrder entry.
# Callback code should be allowed to throw any OData exceptions which again
should be handled gracefully by the Olingo code.
# Additionally we may have to introduce validations in Olingo code post call
back execution to prevent any data malformation as part of callback execution.
Also, please find below the client side code for callback execution.
{code:title=CustomODataJPAServiceFactory.java|borderStyle=solid}
public class CustomODataJPAServiceFactory extends ODataJPAServiceFactory {
@Override
public ODataJPAContext initializeODataJPAContext() throws
ODataJPARuntimeException {
// code to intialize OdataJPAContext.
}
@Override
public T getCallback(final Class
callbackInterface) {
T callback = null;
if (callbackInterface.isAssignableFrom(ReadCallback.class)) {
callback = (T) new ReadCallback();
}
return callback;
}
public static class ReadCallback implements BeforeReadEntityCallback,
ODataEntityBeforeReadCallback, AfterReadEntityCallback,
ODataEntityAfterReadCallback
{
@Override
public void handle(String entitySetName, ODataContext
odataContext, List lstObjects,
EntityManager entityManager) {
}
@Override
public boolean isAfterReadCallbackEnabled() {
return false;
}
@Override
public boolean isBeforeReadCallbackEnabled() {
return true;
}
@Override
/***
* This callback method is used to customize OData Read
operation.
* Below method customizes OData GET request for SalesOrders by
* 1. appending $filter=LastChangedUserName eq 'SPIELERB'.
* 2. adds $top=2 to the URL.
*/
public void handle(UriInfoImpl uriInfo, ODataRequest request,
EntityManager entityManager) {
if(request.getMethod() == ODataHttpMethod.GET){
String entitySetName = null;
try {
if (uriInfo.getTargetEntitySet() != null)
entitySetName =
uriInfo.getTargetEntitySet().getName();
if("SalesOrderTypes".equalsIgnoreCase(entitySetName))
{
String filter ="LastChangedUserName eq
'SPIELERB'";
EdmType targetType =
uriInfo.getTargetType();
// Set/Update the filter expression to
UriInfo
uriInfo.setFilter(new
FilterParserImpl((EdmEntityType) targetType).parseFilterString(filter, true));
// Set/Update $top in UriInfo
uriInfo.setTop(2);
}
} catch (ODataException e) {
// Log Exception & throw it back to Olingo ???
}
}
}
}
{code}
Thanks and Regards,
*Santosh*
was (Author: santosh kumar):
Hi [~mirbo],
Sorry for delay in response.
PFA Git Diff File
[file:///C:/Users/I324363/git/olingo-odata-callback/olingo-odata2/olingo-odata2.diff]
for the PoC I did on this topic.
The patch includes changes only for OData Read call back. Few points
