Creating a dataview based on a custom field

I know that I can do what I want with custom fields but I’m wondering if there’s a way I can do this with a dataview.

I’ve added Contract Item to Cases. The Contract Item is one of the contract detail items based on the Case Contract field. No problems there.

I want to display some field values from the Contract Detail record and from some attributes associated with the Contract Detail’s recurring item (which is a non-stock item record).

I was starting with my graph extension and was going to add a simple data view along the lines of:

  public PXSelect<ContractDetail
      ,Where<ContractDetail.contractItemID
          ,Equal<Current<CRCase.usrContractItemID>>
          ,And<ContractDetail.contractID
            ,Equal<Current<CRCase.contractID>>
          >
      >
      >  CurrentContractItem;

But CRCase doesn’t contain usrContractItemID since that field comes from my DAC extension.

Can I create a data view this way in my graph extension?  Or do I have to create the data view with a parameter and then somehow refresh the data view after I have retrieved the case record or updated the contract item no field?