BIP 11G - Retrieving a cursor from a function defined in a package

Question

We had previously deployed reports in OBIP 10G....
The reports deployed in OBIP 10G used an XDO file to interact with the database and return data in XML format.
This action used to be defined in the ‘sqlStatement’ tag of the XDO file.
<dataQuery>
<sqlStatement name="Q1"> select PK_AP_GEN_REP.AP_GEN_REP('AP_CH_R101',1) FROM DUAL </sqlStatement>
</dataQuery>
For this it would invoke our package called ‘PK_AP_GEN_REP’ and pass the report specific function name ('AP_CH_R101') to it as an input parameter.
This returned a cursor.
Hereafter the resultant cursor from above would get each column mapped with those mentioned in ‘dataStructure’ tags of XDO file to form an XML file.
Currently we are trying the same in OBIP 11G.
We are creating the dataset with SQL query
The problem is that the SQL statement “select PK_AP_GEN_REP.AP_GEN_REP('AP_CH_R101',1) FROM DUAL” is not effective.
Also if the above query is fired it does not retrieve the column names to define the data structure.
Solutions tried:-
1.     Forcefully defining the data-structure in XDM file created for this report. This did not work.
2.     Firing a Before “Event Trigger”. This only works if the function is returning a Boolean and not a cursor.
We tried modifying the function to return a Boolean and to populate the report specific table which could be queried to fetch the records.
We defined Oracle DB Default Package = PK_AP_GEN_REP
We defined the trigger as PK_AP_GEN_REP.AP_GEN_REP('AP_CH_R101',1)
Now creating the dataset with SQL query does not return any data.
It is giving the following error:-
"XML document must have a top level element. Error processing resource 'http://iflmud5im00094:9704/xmlpserver/servlet/xdo'."
However the query fires if Oracle DB Default Package is reset to nothing...But in this case the event trigger did not fire.
If there is a wayout involving any of the above 2 steps or any other way please share the solution
Kindly let me know how I may handle this issue of Retrieving a cursor from a function defined in a package in BIP 11g.

Answer 1

Further regarding this....
Not sure regarding performance issues of using pipelined functions
Just to share with you that instead of what you suggested I have tried out returning a 'table' type object from a PL/SQL function after CAST ing the required query to this Object.
Stretching the discussion forward, is there a way to cast a ref cursor into a plsql table.
This could absolutely fit my requirement...
Thanks in advance