Add flux integrated boundary condition

Author: nmnobre

include/bcs/MFEMScalarFunctorFEFluxIntegratedBC.h

@@ -0,0 +1,19 @@
+#pragma once
+#include "MFEMIntegratedBC.h"
+
+class MFEMScalarFunctorFEFluxIntegratedBC : public MFEMIntegratedBC
+{
+public:
+  static InputParameters validParams();
+
+  MFEMScalarFunctorFEFluxIntegratedBC(const InputParameters & parameters);
+
+  // Create MFEM integrator to apply to the RHS of the weak form. Ownership managed by the caller.
+  virtual mfem::LinearFormIntegrator * createLFIntegrator();
+
+  // Create MFEM integrator to apply to the LHS of the weak form. Ownership managed by the caller.
+  virtual mfem::BilinearFormIntegrator * createBFIntegrator();
+
+protected:
+  mfem::Coefficient & _coef;
+};

src/bcs/MFEMScalarFunctorFEFluxIntegratedBC.C

@@ -0,0 +1,35 @@
+#include "MFEMScalarFunctorFEFluxIntegratedBC.h"
+
+registerMooseObject("PlatypusApp", MFEMScalarFunctorFEFluxIntegratedBC);
+
+InputParameters
+MFEMScalarFunctorFEFluxIntegratedBC::validParams()
+{
+  InputParameters params = MFEMIntegratedBC::validParams();
+  params.addRequiredParam<MFEMScalarCoefficientName>(
+      "coefficient",
+      "The coefficient which will be used in the integrated BC. A coefficient can be be any of "
+      "the following: a variable, an MFEM material property, a function, or a post-processor.");
+  return params;
+}
+
+MFEMScalarFunctorFEFluxIntegratedBC::MFEMScalarFunctorFEFluxIntegratedBC(
+    const InputParameters & parameters)
+  : MFEMIntegratedBC(parameters),
+    _coef(getScalarCoefficient(getParam<MFEMScalarCoefficientName>("coefficient")))
+{
+}
+
+// Create MFEM integrator to apply to the RHS of the weak form. Ownership managed by the caller.
+mfem::LinearFormIntegrator *
+MFEMScalarFunctorFEFluxIntegratedBC::createLFIntegrator()
+{
+  return new mfem::VectorFEBoundaryFluxLFIntegrator(_coef);
+}
+
+// Create MFEM integrator to apply to the LHS of the weak form. Ownership managed by the caller.
+mfem::BilinearFormIntegrator *
+MFEMScalarFunctorFEFluxIntegratedBC::createBFIntegrator()
+{
+  return nullptr;
+}