read dofmanager if it was written.

[[Imported from SVN: r3799]]

io/file/grapedataio.hh

@@ -161,13 +161,14 @@ namespace Dune {
     double time, int timestep, int precision )
   {
     // write dof manager, that corresponds to grid
+    bool hasDm = false;
     {
       typedef DofManager<GridImp> DofManagerType;
       typedef DofManagerFactory<DofManagerType> DMFactoryType;
 
       std::string dmname(fnprefix);
       dmname += "_dm";
-      DMFactoryType::writeDofManager(grid,dmname,timestep);
+      hasDm = DMFactoryType::writeDofManager(grid,dmname,timestep);
     }
 
     // write Grid itself
@@ -177,6 +178,8 @@ namespace Dune {
       file << "Grid: "   << transformToGridName(grid.type()) << std::endl;
       file << "Format: " << ftype <<  std::endl;
       file << "Precision: " << precision << std::endl;
+      int writeDm = (hasDm) ? 1 : 0;
+      file << "DofManager: " << writeDm << std::endl;
 
       GrapeIOStringType fnstr = genFilename(path,fnprefix,timestep,precision);
 
@@ -221,14 +224,18 @@ namespace Dune {
     int precision = 6;
     readParameter(fnprefix,"Precision",precision);
 
+    int hasDm = 0;
+    readParameter(fnprefix,"DofManager",hasDm);
+
     const char *path = "";
     GrapeIOStringType fn = genFilename(path,fnprefix,timestep,precision);
     std::cout << "Read file: fnprefix = `" << fn << "' \n";
 
+    bool succeded = false;
     switch (ftype)
     {
-    case xdr  :   return grid.template readGrid<xdr>  (fn,time);
-    case ascii :   return grid.template readGrid<ascii>(fn,time);
+    case xdr  :   succeded = grid.template readGrid<xdr>  (fn,time); break;
+    case ascii :   succeded = grid.template readGrid<ascii>(fn,time); break;
     default :
     {
       std::cerr << ftype << " GrapeIOFileFormatType not supported at the moment! \n";
@@ -237,7 +244,21 @@ namespace Dune {
       return false;
     }
     }
-    return false;
+
+    // write dof manager, that corresponds to grid
+    if(hasDm)
+    {
+      typedef DofManager<GridImp> DofManagerType;
+      typedef DofManagerFactory<DofManagerType> DMFactoryType;
+
+      std::string dmname(fn);
+      dmname += "_dm";
+      //std::cout << "Read DofManager from file " << dmname << "\n";
+      // this call creates DofManager if not already existing
+      DMFactoryType::getDofManager(grid);
+      succeded = DMFactoryType::writeDofManager(grid,dmname,timestep);
+    }
+    return succeded;
   }
 
   template <class GridType>