[ 
https://issues.apache.org/jira/browse/OLINGO-1129?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16105064#comment-16105064
 ] 

Hui Wang edited comment on OLINGO-1129 at 7/28/17 3:10 PM:
-----------------------------------------------------------

Hi Ramya,

Thank you for the details. We already set the inlineEntity correctly in the 
NavigationLink. 
When doing $expand on a navigation property, the inline entities would be 
completely fetched from the database including all of their properties. If type 
casts is included in the expand, our data generator processor will fetch the 
properties that belong to the derived type as well. I think everything has been 
well prepared before the Serializer. But the Serializer didn't serialize the 
additional properties that were already included in the inlineEntity into JSON.

I think in ODataJsonSerializer.writeExpandedNavigationProperty(), these lines 
are responsible for writing the inline entity into the json: 

{code:java}
      } else {
        writeEntity(metadata, property.getType(), 
navigationLink.getInlineEntity(), null,
            innerExpand, toDepth, innerSelect, writeOnlyRef, ancestors, json);
      }
{code}
It seems that property.getType() provides the EdmEntityType that indicates what 
entity type should be written, and navigationLink.getInlineEntity() gets the 
inline entity from the prepared object (here we have provided all of the 
properties). I think the problem is that the EdmEntityType retrieved by 
property.getType() is only a base type because that is how the navigation 
property is defined in the metadata. And it didn't inform writeEntity() about 
the derived type, therefore the method didn't know it should write the extra 
properties for the derived type. 


Hui



was (Author: huiw@ng):
Hi Ramya,

Thank you for the details. We already set the inlineEntity correctly in the 
NavigationLink. 
When doing $expand on a navigation property, the inline entities would be 
completely fetched from the database including all of their properties. If type 
casts is included in the expand, our data generator processor will fetch the 
properties that belong to the derived type as well. I think everything has been 
well prepared before the Serializer. But the Serializer didn't serialize the 
additional properties that were already included in the EntityCollection into 
JSON.

I think in ODataJsonSerializer.writeExpandedNavigationProperty(), these lines 
are responsible for writing the inline entity into the json: 

{code:java}
      } else {
        writeEntity(metadata, property.getType(), 
navigationLink.getInlineEntity(), null,
            innerExpand, toDepth, innerSelect, writeOnlyRef, ancestors, json);
      }
{code}
It seems that property.getType() provides the EdmEntityType that indicates what 
entity type should be written, and navigationLink.getInlineEntity() gets the 
inline entity from the prepared object (here we have provided all of the 
properties). I think the problem is that the EdmEntityType retrieved by 
property.getType() is only a base type because that is how the navigation 
property is defined in the metadata. And it didn't inform writeEntity() about 
the derived type, therefore the method didn't know it should write the extra 
properties for the derived type. 


Hui


> ODataJsonSerializer Does Not Support Derived Type in $expand Option
> -------------------------------------------------------------------
>
>                 Key: OLINGO-1129
>                 URL: https://issues.apache.org/jira/browse/OLINGO-1129
>             Project: Olingo
>          Issue Type: New Feature
>          Components: odata4-server
>    Affects Versions: (Java) V4 4.3.0
>            Reporter: Hui Wang
>            Priority: Minor
>
> Currently we need to use type casting to a derived type in $expand. Here is 
> the corresponding part in the OData Protocol. 
> http://docs.oasis-open.org/odata/odata/v4.0/errata03/os/complete/part2-url-conventions/odata-v4.0-errata03-os-part2-url-conventions-complete.html#_Toc453752352
> To reproduce: 
> Here is an example URL provided in the documentation that could be used for 
> reproducing the defect: 
> http://host/service/Orders?$expand=Customer/Model.VipCustomer
> In the current 4.3 version, ODataJsonSerializer only deals with expand on 
> Customer but ignores the type filter Model.VipCustomer. It means, the 
> response would only show the content of super type Customer. Any custom 
> properties in derived type VipCustomer wouldn't be returned. 



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

Reply via email to