Passing time information to a custom boundary face integrator for weak imposition of time-dependent boundary condition

[FH-9]

Hi,

I have a NonlinearForm object nonlinearform that belongs to a TimeDependentOperator class performing DG semi-discretization for Euler equations. I have implemented several custom boundary face integrators for weak imposition of boundary conditions, which I add to my scheme through nonlinearform->AddBdrFaceIntegrator(NonlinearFormIntegrator* bfi, Array<int>& bdr_marker).
Now one of the boundary integrators should weakly impose a time-dependent fixed state (e.g., top boundary in Double Mach Reflection problem). I was thinking of adding a VectorFunctionCoefficient object bc_fun (that would be initialized with the time-dependent boundary function of interest) to my custom integrator and then calling bc_fun.Eval(state2, &Tr, ip). Getting Tr and ip is easy as I will have access to them in the custom AssembleFaceVector method. However, Eval also needs the current time to calculate the time-dependent boundary state and I don't have access to it. How could I pass the time information from the TimeDependentOperator to only a specific (applied only to a part of the boundary) boundary integrator among the boundary integrators added through nonlinearform->AddBdrFaceIntegrator?

Thank you in advance.

Farhad