[io][vtk] introduce compatibility layer with new/old grid vars

dumux/io/vtkoutputmodule.hh

@@ -43,7 +43,9 @@
 
 #include <dumux/common/parameters.hh>
 #include <dumux/io/format.hh>
+
 #include <dumux/discretization/method.hh>
+#include <dumux/discretization/fvgridvariables.hh>
 
 #include "vtkfunction.hh"
 #include "velocityoutput.hh"
@@ -378,8 +380,18 @@ public:
     }
 
 protected:
+    // extract the grid volume variables from the grid variables (experimental interface)
+    template<bool isExperimental = Experimental::areExperimentalGridVars<GridVariables>,
+             std::enable_if_t<isExperimental, int> = 0>
+    decltype(auto) gridVolVars() const { return gridVariables_.gridVolVars(); }
+
+    // extract the grid volume variables from the grid variables (experimental interface)
+    template<bool isExperimental = Experimental::areExperimentalGridVars<GridVariables>,
+             std::enable_if_t<!isExperimental, int> = 0>
+    decltype(auto) gridVolVars() const { return gridVariables_.curGridVolVars(); }
+
     // some return functions for differing implementations to use
-    const auto& problem() const { return gridVariables_.curGridVolVars().problem(); }
+    const auto& problem() const { return gridVolVars().problem(); }
     const GridVariables& gridVariables() const { return gridVariables_; }
     const GridGeometry& gridGeometry() const { return gridVariables_.gridGeometry(); }
     const SolutionVector& sol() const { return sol_; }
@@ -447,7 +459,7 @@ private:
                 const auto eIdxGlobal = gridGeometry().elementMapper().index(element);
 
                 auto fvGeometry = localView(gridGeometry());
-                auto elemVolVars = localView(gridVariables_.curGridVolVars());
+                auto elemVolVars = localView(gridVolVars());
 
                 // If velocity output is enabled we need to bind to the whole stencil
                 // otherwise element-local data is sufficient
@@ -634,7 +646,7 @@ private:
                 const auto numCorners = element.subEntities(dim);
 
                 auto fvGeometry = localView(gridGeometry());
-                auto elemVolVars = localView(gridVariables_.curGridVolVars());
+                auto elemVolVars = localView(gridVolVars());
 
                 // resize element-local data containers
                 for (std::size_t i = 0; i < volVarScalarDataInfo_.size(); ++i)

dumux/porousmediumflow/velocity.hh

@@ -36,6 +36,7 @@
 #include <dumux/common/parameters.hh>
 #include <dumux/discretization/method.hh>
 #include <dumux/discretization/elementsolution.hh>
+#include <dumux/discretization/fvgridvariables.hh>
 #include <dumux/flux/traits.hh>
 
 namespace Dumux {
@@ -108,7 +109,7 @@ public:
      * \param gridVariables The grid variables
      */
     PorousMediumFlowVelocity(const GridVariables& gridVariables)
-    : problem_(gridVariables.curGridVolVars().problem())
+    : problem_(getProblem_(gridVariables))
     , gridGeometry_(gridVariables.gridGeometry())
     , gridVariables_(gridVariables)
     {
@@ -460,6 +461,15 @@ private:
     }
 
 private:
+
+    // extract problem from grid vars (experimental interface)
+    template<class GV, std::enable_if_t<Experimental::areExperimentalGridVars<GV>, int> = 0>
+    const Problem& getProblem_(const GV& gv) { return gv.gridVolVars().problem(); }
+
+    // extract problem from grid vars (standards interface)
+    template<class GV, std::enable_if_t<!Experimental::areExperimentalGridVars<GV>, int> = 0>
+    const Problem& getProblem_(const GV& gv) { return gv.curGridVolVars().problem(); }
+
     const Problem& problem_;
     const GridGeometry& gridGeometry_;
     const GridVariables& gridVariables_;

dumux/porousmediumflow/velocityoutput.hh

@@ -29,9 +29,11 @@
 #include <dune/common/float_cmp.hh>
 
 #include <dumux/common/parameters.hh>
+
 #include <dumux/io/velocityoutput.hh>
 #include <dumux/discretization/method.hh>
 #include <dumux/discretization/elementsolution.hh>
+#include <dumux/discretization/fvgridvariables.hh>
 #include <dumux/porousmediumflow/velocity.hh>
 
 namespace Dumux {
@@ -67,6 +69,15 @@ class PorousMediumFlowVelocityOutput : public VelocityOutput<GridVariables>
     using Problem = typename GridVolumeVariables::Problem;
     using VelocityBackend = PorousMediumFlowVelocity<GridVariables, FluxVariables>;
 
+    struct hasCurGridVolVars
+    {
+        template<class GV>
+        auto operator()(const GV& gv) -> decltype(gv.curGridVolVars()) {}
+    };
+
+    static constexpr auto isOldGVInterface =
+        decltype(isValid(hasCurGridVolVars())(std::declval<GridVariables>()))::value;
+
 public:
     using VelocityVector = typename ParentType::VelocityVector;
 
@@ -78,7 +89,12 @@ public:
     PorousMediumFlowVelocityOutput(const GridVariables& gridVariables)
     {
         // check, if velocity output can be used (works only for cubes so far)
-        enableOutput_ = getParamFromGroup<bool>(gridVariables.curGridVolVars().problem().paramGroup(), "Vtk.AddVelocity");
+        // compatibility layer with new and old-style grid variables
+        if constexpr (Experimental::areExperimentalGridVars<GridVariables>)
+            enableOutput_ = getParamFromGroup<bool>(gridVariables.gridVolVars().problem().paramGroup(), "Vtk.AddVelocity");
+        else
+            enableOutput_ = getParamFromGroup<bool>(gridVariables.curGridVolVars().problem().paramGroup(), "Vtk.AddVelocity");
+
         if (enableOutput_)
             velocityBackend = std::make_unique<VelocityBackend>(gridVariables);
     }