Hi Christian,
From my understanding, you are trying to fetch the data from Various PA and OM infotypes within a class. As Jonathan suggested you can use FM "HR_READ_INFOTYPE" for reading PA related infotype data and "RH_READ_INFTY" for reading OM related infotype data within a class. But for each infotype you have to call them seperately and store it in a internal table and later you can merge it using a loop with the help of unique key.
With Regards,
Giriesh M