Master Detail Navigation with dependencies of 3 entities

Question

I built an App with the Master Detail Template. Normaly you navigate between 2 entities. For example Storage Type (Master Page) and the belonging Quantity (Detail Page). My problem is, that the Storage Type depends on a Warehouse number, which is fix in my case. The navigation to the detail page needs 2 key ids. The Storage Type is given, but my Warehouse Number has the value "null" but should be "Y01". How do i manually assign the Warehouse Number in my code or better there do i find this parameter ?

RequestPayload

--batch_3d6f-76ed-a97a Content-Type: application/http Content-Transfer-Encoding: binary

GET LagertypSet(Lgnum=null,Lgtyp='D41') HTTP/1.1

sap-contextid-accept: header Accept: application/json Accept-Language: de-DE DataServiceVersion: 2.0 MaxDataServiceVersion: 2.0 x-csrf-token: Uae5fDde8SUoJexmuZEsug==

--batch_3d6f-76ed-a97a--

Kind Regards, Felix

Answer 1

Just as a little starting note: It is usually a good practice to not hard-code the warehouse number in your code, but to get it from a configuration table somewhere, either in your application, or better from the back-end (e.g. user-parameters?)

Anyway, the secret lies somewhere in the createKey method that is probably part of the code you generated? The createKey constructs the portion LagertypSet(Lgnum=null,Lgtyp='D41') based on the parameters you pass and on the metamodel of your service. In your situation, this should look like:

var key = createKey("/LagertypeSet", { 
    Lgnum: somethingThatsNull, 
    Lgtyp: keyFromMaster
});

The Lgnum shouldn't be pointing to the variable that's null anymore, but to the variable that contains Y01. E.g.:

var defaultWarehouse = "Y01";
var key = createKey("/LagertypeSet", { 
    Lgnum: defaultWarehouse, 
    Lgtyp: keyFromMaster
});

I hope with these pointers, you'll be able to improve your code. Good luck!