source: XIOS/dev/dev_olga/src/node/field.cpp @ 1136

#include "field.hpp"

#include "attribute_template.hpp"
#include "object_template.hpp"
#include "group_template.hpp"

#include "node_type.hpp"
#include "calendar_util.hpp"
#include "message.hpp"
#include "xios_spl.hpp"
#include "type.hpp"
#include "timer.hpp"
#include "context_client.hpp"
#include "context_server.hpp"
#include <set>
#include "garbage_collector.hpp"
#include "source_filter.hpp"
#include "store_filter.hpp"
#include "file_writer_filter.hpp"
#include "pass_through_filter.hpp"
#include "filter_expr_node.hpp"
#include "lex_parser.hpp"
#include "temporal_filter.hpp"
#include "spatial_transform_filter.hpp"
#include "file_server_writer_filter.hpp"

namespace xios{

   /// ////////////////////// Définitions ////////////////////// ///

   CField::CField(void)
      : CObjectTemplate<CField>(), CFieldAttributes()
      , grid(), file()
      , written(false)
      , nstep(0), nstepMax(0)
      , hasOutputFile(false)
      , domAxisScalarIds_(vector<StdString>(3,""))
      , areAllReferenceSolved(false), isReferenceSolved(false), isReferenceSolvedAndTransformed(false)
      , useCompressedOutput(false)
      , wasDataAlreadyReceivedFromServer(false)
   { setVirtualVariableGroup(CVariableGroup::create(getId() + "_virtual_variable_group")); }

   CField::CField(const StdString& id)
      : CObjectTemplate<CField>(id), CFieldAttributes()
      , grid(), file()
      , written(false)
      , nstep(0), nstepMax(0)
      , hasOutputFile(false)
      , domAxisScalarIds_(vector<StdString>(3,""))
      , areAllReferenceSolved(false), isReferenceSolved(false), isReferenceSolvedAndTransformed(false)
      , useCompressedOutput(false)
      , wasDataAlreadyReceivedFromServer(false)
   { setVirtualVariableGroup(CVariableGroup::create(getId() + "_virtual_variable_group")); }

   CField::~CField(void)
   {}

  //----------------------------------------------------------------

   void CField::setVirtualVariableGroup(CVariableGroup* newVVariableGroup)
   {
      this->vVariableGroup = newVVariableGroup;
   }

   CVariableGroup* CField::getVirtualVariableGroup(void) const
   {
      return this->vVariableGroup;
   }

   std::vector<CVariable*> CField::getAllVariables(void) const
   {
      return this->vVariableGroup->getAllChildren();
   }

   void CField::solveDescInheritance(bool apply, const CAttributeMap* const parent)
   {
      SuperClassAttribute::setAttributes(parent, apply);
      this->getVirtualVariableGroup()->solveDescInheritance(apply, NULL);
   }

  //----------------------------------------------------------------

  bool CField::dispatchEvent(CEventServer& event)
  {
    if (SuperClass::dispatchEvent(event)) return true;
    else
    {
      switch(event.type)
      {
        case EVENT_ID_UPDATE_DATA :
          recvUpdateData(event);
          return true;
          break;

        case EVENT_ID_READ_DATA :
          recvReadDataRequest(event);
          return true;
          break;

        case EVENT_ID_READ_DATA_READY :
          recvReadDataReady(event);
          return true;
          break;

        case EVENT_ID_ADD_VARIABLE :
          recvAddVariable(event);
          return true;
          break;

        case EVENT_ID_ADD_VARIABLE_GROUP :
          recvAddVariableGroup(event);
          return true;
          break;

        default :
          ERROR("bool CField::dispatchEvent(CEventServer& event)", << "Unknown Event");
          return false;
      }
    }
  }

  void CField::sendUpdateData(const CArray<double,1>& data)
  {
    CTimer::get("XIOS Send Data").resume();

    CContext* context = CContext::getCurrent();
      CContextClient* client = (!context->hasServer) ? context->client : this->file->getContextClient();

      CEventClient event(getType(), EVENT_ID_UPDATE_DATA);

      map<int, CArray<int,1> >::iterator it;
      list<CMessage> list_msg;
      list<CArray<double,1> > list_data;

      if (!grid->doGridHaveDataDistributed())
      {
         if (client->isServerLeader())
         {
            for (it = grid->storeIndex_toSrv.begin(); it != grid->storeIndex_toSrv.end(); it++)
            {
              int rank = it->first;
              CArray<int,1>& index = it->second;

              list_msg.push_back(CMessage());
              list_data.push_back(CArray<double,1>(index.numElements()));

              CArray<double,1>& data_tmp = list_data.back();
              for (int n = 0; n < data_tmp.numElements(); n++) data_tmp(n) = data(index(n));

              list_msg.back() << getId() << data_tmp;
              event.push(rank, 1, list_msg.back());
            }
            client->sendEvent(event);
         }
         else client->sendEvent(event);
      }
      else
      {
        for (it = grid->storeIndex_toSrv.begin(); it != grid->storeIndex_toSrv.end(); it++)
        {
          int rank = it->first;
          CArray<int,1>& index = it->second;

          list_msg.push_back(CMessage());
          list_data.push_back(CArray<double,1>(index.numElements()));

          CArray<double,1>& data_tmp = list_data.back();
          for (int n = 0; n < data_tmp.numElements(); n++) data_tmp(n) = data(index(n));

          list_msg.back() << getId() << data_tmp;
          event.push(rank, grid->nbSenders[0][rank], list_msg.back());
        }
        client->sendEvent(event);
      }
    // }

    CTimer::get("XIOS Send Data").suspend();
  }

  // void CField::sendUpdateData(const CArray<double,1>& data, CContextClient* client)
  // {
  //   CTimer::get("XIOS Send Data").resume();

  //   CEventClient event(getType(), EVENT_ID_UPDATE_DATA);

  //   map<int, CArray<int,1> >::iterator it;
  //   list<CMessage> list_msg;
  //   list<CArray<double,1> > list_data;

  //   if (!grid->doGridHaveDataDistributed())
  //   {
  //      if (client->isServerLeader())
  //      {
  //         for (it = grid->storeIndex_toSrv.begin(); it != grid->storeIndex_toSrv.end(); it++)
  //         {
  //           int rank = it->first;
  //           CArray<int,1>& index = it->second;

  //           list_msg.push_back(CMessage());
  //           list_data.push_back(CArray<double,1>(index.numElements()));

  //           CArray<double,1>& data_tmp = list_data.back();
  //           for (int n = 0; n < data_tmp.numElements(); n++) data_tmp(n) = data(index(n));

  //           list_msg.back() << getId() << data_tmp;
  //           event.push(rank, 1, list_msg.back());
  //         }
  //         client->sendEvent(event);
  //      }
  //      else client->sendEvent(event);
  //   }
  //   else
  //   {
  //     for (it = grid->storeIndex_toSrv.begin(); it != grid->storeIndex_toSrv.end(); it++)
  //     {
  //       int rank = it->first;
  //       CArray<int,1>& index = it->second;

  //       list_msg.push_back(CMessage());
  //       list_data.push_back(CArray<double,1>(index.numElements()));

  //       CArray<double,1>& data_tmp = list_data.back();
  //       for (int n = 0; n < data_tmp.numElements(); n++) data_tmp(n) = data(index(n));

  //       list_msg.back() << getId() << data_tmp;
  //       event.push(rank, grid->nbSenders[rank], list_msg.back());
  //     }
  //     client->sendEvent(event);
  //   }
  //   CTimer::get("XIOS Send Data").suspend();
  // }

  void CField::recvUpdateData(CEventServer& event)
  {
    std::map<int,CBufferIn*> rankBuffers;

    list<CEventServer::SSubEvent>::iterator it;
    string fieldId;

    for (it = event.subEvents.begin(); it != event.subEvents.end(); ++it)
    {
      int rank = it->rank;
      CBufferIn* buffer = it->buffer;
      *buffer >> fieldId;
      rankBuffers[rank] = buffer;
    }
    get(fieldId)->recvUpdateData(rankBuffers);
  }

  void  CField::recvUpdateData(std::map<int,CBufferIn*>& rankBuffers)
  {
    CContext* context = CContext::getCurrent();

    size_t sizeData = 0;
    if (0 == recvDataSrv.numElements())
    {            
      CArray<int,1>& storeClient = grid->storeIndex_client;

      // Gather all data from different clients      
      recvDataSrv.resize(storeClient.numElements());
      recvFoperationSrv = boost::shared_ptr<func::CFunctor>(new func::CInstant(recvDataSrv));
    }

    CArray<double,1> recv_data_tmp(recvDataSrv.numElements());    
    const CDate& currDate = context->getCalendar()->getCurrentDate();
    const CDate opeDate   = last_operation_srv +freq_op + freq_operation_srv - freq_op;

    if (opeDate <= currDate)
    {
      for (map<int, CArray<size_t, 1> >::iterator it = grid->outLocalIndexStoreOnClient.begin(); it != grid->outLocalIndexStoreOnClient.end(); ++it)
      {
        CArray<double,1> tmp;
        CArray<size_t,1>& indexTmp = it->second;
        *(rankBuffers[it->first]) >> tmp;
        for (int idx = 0; idx < indexTmp.numElements(); ++idx)
        {
          recv_data_tmp(indexTmp(idx)) = tmp(idx);
        }      
      }
    }

    this->setData(recv_data_tmp);
  }

  void CField::writeUpdateData(const CArray<double,1>& data)
  {
    CContext* context = CContext::getCurrent();

    const CDate& currDate = context->getCalendar()->getCurrentDate();
    const CDate opeDate      = last_operation_srv +freq_op + freq_operation_srv - freq_op;
    const CDate writeDate    = last_Write_srv     + freq_write_srv;

    if (opeDate <= currDate)
    {
      (*recvFoperationSrv)(data);
      last_operation_srv = currDate;
    }

    if (writeDate < (currDate + freq_operation_srv))
    {
      recvFoperationSrv->final();
      last_Write_srv = writeDate;
      grid->computeWrittenIndex();
      writeField();
      lastlast_Write_srv = last_Write_srv;
    }
  }
  
//   void  CField::recvUpdateData(vector<int>& ranks, vector<CBufferIn*>& buffers)
//   {
//     CContext* context = CContext::getCurrent();

//     if (data_srv.empty())
//     {
//       for (map<int, CArray<size_t, 1> >::iterator it = grid->outIndexFromClient.begin(); it != grid->outIndexFromClient.end(); ++it)
//       {
//         int rank = it->first;
//         data_srv.insert(std::make_pair(rank, CArray<double,1>(it->second.numElements())));
//         foperation_srv.insert(pair<int,boost::shared_ptr<func::CFunctor> >(rank,boost::shared_ptr<func::CFunctor>(new func::CInstant(data_srv[rank]))));
//       }
//     }

//     const CDate& currDate = context->getCalendar()->getCurrentDate();
//     const CDate opeDate      = last_operation_srv +freq_op + freq_operation_srv - freq_op;
//     const CDate writeDate    = last_Write_srv     + freq_write_srv;

//     if (opeDate <= currDate)
//     {
//       for (int n = 0; n < ranks.size(); n++)
//       {
//         CArray<double,1> data_tmp;
//         *buffers[n] >> data_tmp;
//         (*foperation_srv[ranks[n]])(data_tmp);
//       }
//       last_operation_srv = currDate;
//     }

//     if (writeDate < (currDate + freq_operation_srv))
//     {
//       for (int n = 0; n < ranks.size(); n++)
//       {
//         this->foperation_srv[ranks[n]]->final();
//       }

//       last_Write_srv = writeDate;
//     }

//     if (context->hasClient && context->hasServer)
//     {
//       size_t writtenSize;
// //      if (field->getUseCompressedOutput())
// //        writtenSize = grid->getNumberWrittenIndexes();
// //      else
//         writtenSize = grid->getWrittenDataSize();

//       CArray<double,1> fieldData(writtenSize);
// //      if (!field->default_value.isEmpty()) fieldData = field->default_value;

// //      if (field->getUseCompressedOutput())
// //        field->outputCompressedField(fieldData);
// //      else
//         this->outputField(fieldData);
//       sendUpdateData(fieldData);
//     }
//     if (!context->hasClient && context->hasServer)
//     {
//       writeField();
//     }

//     lastlast_Write_srv = last_Write_srv;

//   }

  void CField::writeField(void)
  {
    if (!getRelFile()->allDomainEmpty)
    {
      if (grid->doGridHaveDataToWrite() || getRelFile()->type == CFile::type_attr::one_file)
      {
        getRelFile()->checkWriteFile();
        this->incrementNStep();
        getRelFile()->getDataOutput()->writeFieldData(CField::get(this));
      }
    }
  }

  void CField::sendReadDataRequest(const CDate& tsDataRequested)
  {
    CContext* context = CContext::getCurrent();
//    CContextClient* client = context->client;
    CContextClient* client = (!context->hasServer) ? context->client : this->file->getContextClient();


    lastDataRequestedFromServer = tsDataRequested;

    CEventClient event(getType(), EVENT_ID_READ_DATA);
    if (client->isServerLeader())
    {
      CMessage msg;
      msg << getId();
      const std::list<int>& ranks = client->getRanksServerLeader();
      for (std::list<int>::const_iterator itRank = ranks.begin(), itRankEnd = ranks.end(); itRank != itRankEnd; ++itRank)
        event.push(*itRank, 1, msg);
      client->sendEvent(event);
    }
    else client->sendEvent(event);
  }

  /*!
  Send request new data read from file if need be, that is the current data is out-of-date.
  \return true if and only if some data was requested
  */
  bool CField::sendReadDataRequestIfNeeded(void)
  {
    const CDate& currentDate = CContext::getCurrent()->getCalendar()->getCurrentDate();

    bool dataRequested = false;
    while (currentDate >= lastDataRequestedFromServer)
    {
      info(20) << "currentDate : " << currentDate << endl ;
      info(20) << "lastDataRequestedFromServer : " << lastDataRequestedFromServer << endl ;
      info(20) << "file->output_freq.getValue() : " << file->output_freq.getValue() << endl ;
      info(20) << "lastDataRequestedFromServer + file->output_freq.getValue() : " << lastDataRequestedFromServer + file->output_freq << endl ;

      sendReadDataRequest(lastDataRequestedFromServer + file->output_freq);

      dataRequested = true;
    }
    return dataRequested;
  }

  void CField::recvReadDataRequest(CEventServer& event)
  {
    CBufferIn* buffer = event.subEvents.begin()->buffer;
    StdString fieldId;
    *buffer >> fieldId;
    get(fieldId)->recvReadDataRequest();
  }

  void CField::recvReadDataRequest(void)
  {
    CContext* context = CContext::getCurrent();
    CContextClient* client = context->client;    

    CEventClient event(getType(), EVENT_ID_READ_DATA_READY);
    std::list<CMessage> msgs;

    bool hasData = readField();

    
    if (!grid->doGridHaveDataDistributed())
    {
       if (client->isServerLeader())
       {
          if (0 != recvDataSrv.numElements())
          {            
            const std::list<int>& ranks = client->getRanksServerLeader();
            for (std::list<int>::const_iterator itRank = ranks.begin(), itRankEnd = ranks.end(); itRank != itRankEnd; ++itRank)
            {
              msgs.push_back(CMessage());
              CMessage& msg = msgs.back();
              msg << getId();
              if (hasData)
                msg << getNStep() - 1 << recvDataSrv;
              else
                msg << int(-1);
              event.push(*itRank, 1, msg);
            }
          }

          client->sendEvent(event);
       }
       else
       {
          client->sendEvent(event);
       }
    }
    else
    {
      for (map<int, CArray<size_t, 1> >::iterator it = grid->outLocalIndexStoreOnClient.begin(); 
                                                  it != grid->outLocalIndexStoreOnClient.end(); ++it)
      {
        CArray<size_t,1>& indexTmp = it->second;
        CArray<double,1> tmp(indexTmp.numElements());
        for (int idx = 0; idx < indexTmp.numElements(); ++idx)
        {
          tmp(idx) = recvDataSrv(indexTmp(idx));
        } 

        msgs.push_back(CMessage());
        CMessage& msg = msgs.back();
        msg << getId();
        if (hasData)
          msg << getNStep() - 1 << tmp;
        else
          msg << int(-1);
        event.push(it->first, grid->nbReadSenders[0][it->first], msg);
      }
      client->sendEvent(event);
    }
  }

  bool CField::readField(void)
  {
    grid->computeWrittenIndex();
    if (!getRelFile()->allDomainEmpty)
    {
      if (grid->doGridHaveDataToWrite() || getRelFile()->type == CFile::type_attr::one_file)
      {
        if (0 == recvDataSrv.numElements())
        {            
          CArray<int,1>& storeClient = grid->storeIndex_client;          
          recvDataSrv.resize(storeClient.numElements());          
        }

        getRelFile()->checkReadFile();
        if (!nstepMax)
        {
          nstepMax = getRelFile()->getDataInput()->getFieldNbRecords(CField::get(this));
        }

        this->incrementNStep();

        if (getNStep() > nstepMax && (getRelFile()->cyclic.isEmpty() || !getRelFile()->cyclic) )
          return false;

        getRelFile()->getDataInput()->readFieldData(CField::get(this));
      }
    }

    return true;
  }

  void CField::recvReadDataReady(CEventServer& event)
  {
    string fieldId;
    vector<int> ranks;
    vector<CBufferIn*> buffers;

    list<CEventServer::SSubEvent>::iterator it;
    for (it = event.subEvents.begin(); it != event.subEvents.end(); ++it)
    {
      ranks.push_back(it->rank);
      CBufferIn* buffer = it->buffer;
      *buffer >> fieldId;
      buffers.push_back(buffer);
    }
    get(fieldId)->recvReadDataReady(ranks, buffers);
  }

  void CField::recvReadDataReady(vector<int> ranks, vector<CBufferIn*> buffers)
  {
    CContext* context = CContext::getCurrent();
    int record;
    std::map<int, CArray<double,1> > data;

    bool isEOF = false;

    for (int i = 0; i < ranks.size(); i++)
    {
      int rank = ranks[i];
      *buffers[i] >> record;
      isEOF = (record == int(-1));

      if (!isEOF)
        *buffers[i] >> data[rank];
      else
        break;
    }

    if (wasDataAlreadyReceivedFromServer)
      lastDataReceivedFromServer = lastDataReceivedFromServer + file->output_freq;
    else
    {
      lastDataReceivedFromServer = context->getCalendar()->getInitDate();
      wasDataAlreadyReceivedFromServer = true;
    }

    if (isEOF)
      serverSourceFilter->signalEndOfStream(lastDataReceivedFromServer);
    else
      serverSourceFilter->streamDataFromServer(lastDataReceivedFromServer, data);
  }

   //----------------------------------------------------------------

   void CField::setRelFile(CFile* _file)
   {
      this->file = _file;
      hasOutputFile = true;
   }

   //----------------------------------------------------------------

   StdString CField::GetName(void)    { return StdString("field"); }
   StdString CField::GetDefName(void) { return CField::GetName(); }
   ENodeType CField::GetType(void)    { return eField; }

   //----------------------------------------------------------------

   CGrid* CField::getRelGrid(void) const
   {
      return this->grid;
   }

   //----------------------------------------------------------------

   CFile* CField::getRelFile(void) const
   {
      return this->file;
   }

   int CField::getNStep(void) const
   {
      return this->nstep;
   }

   func::CFunctor::ETimeType CField::getOperationTimeType() const
   {
     return operationTimeType;
   }

   //----------------------------------------------------------------

   void CField::incrementNStep(void)
   {
      this->nstep++;
   }

   void CField::resetNStep(int nstep /*= 0*/)
   {
      this->nstep = nstep;
   }

   void CField::resetNStepMax(void)
   {
      this->nstepMax = 0;
   }

   //----------------------------------------------------------------

   bool CField::isActive(void) const
   {
      return (instantDataFilter != NULL);
   }

   //----------------------------------------------------------------

   bool CField::wasWritten() const
   {
     return written;
   }

   void CField::setWritten()
   {
     written = true;
   }

   //----------------------------------------------------------------

   bool CField::getUseCompressedOutput() const
   {
     return useCompressedOutput;
   }

   void CField::setUseCompressedOutput()
   {
     useCompressedOutput = true;
   }

   //----------------------------------------------------------------

   boost::shared_ptr<COutputPin> CField::getInstantDataFilter()
   {
     return instantDataFilter;
   }

   //----------------------------------------------------------------

   /*!
     Build up graph of grids which plays role of destination and source in grid transformation
     This function should be called before \func solveGridReference()
   */
   void CField::buildGridTransformationGraph()
   {
     CContext* context = CContext::getCurrent();
     if (context->hasClient && !context->hasServer)
//     if (context->hasClient)
     {
       if (grid && !grid->isTransformed() && hasDirectFieldReference() && grid != getDirectFieldReference()->grid)
       {
         grid->addTransGridSource(getDirectFieldReference()->grid);
       }
     }
   }

   /*!
     Generate a new grid destination if there are more than one grid source pointing to a same grid destination
   */
   void CField::generateNewTransformationGridDest()
   {
     CContext* context = CContext::getCurrent();
     if (context->hasClient && !context->hasServer)
//     if (context->hasClient)
     {
       std::map<CGrid*,std::pair<bool,StdString> >& gridSrcMap = grid->getTransGridSource();
       if (1 < gridSrcMap.size())
       {
         // Search for grid source
         CGrid* gridSrc = grid;
         CField* currField = this;
         std::vector<CField*> hieraField;

         while (currField->hasDirectFieldReference() && (gridSrc == grid))
         {
           hieraField.push_back(currField);
           CField* tmp = currField->getDirectFieldReference();
           currField = tmp;
           gridSrc = currField->grid;
         }

         if (gridSrcMap.end() != gridSrcMap.find(gridSrc))
         {
           CGrid* gridTmp;
           std::pair<bool,StdString> newGridDest = gridSrcMap[gridSrc];
           if (newGridDest.first)
           {
             StdString newIdGridDest = newGridDest.second;
             if (!CGrid::has(newIdGridDest))
             {
                ERROR("CGrid* CGrid::generateNewTransformationGridDest()",
                  << " Something wrong happened! Grid whose id " << newIdGridDest
                  << "should exist ");
             }
             gridTmp = CGrid::get(newIdGridDest);
           }
           else
           {
             StdString newIdGridDest = CGrid::generateId(gridSrc, grid);
             gridTmp = CGrid::cloneGrid(newIdGridDest, grid);

             (gridSrcMap[gridSrc]).first = true;
             (gridSrcMap[gridSrc]).second = newIdGridDest;
           }

           // Update all descendants
           for (std::vector<CField*>::iterator it = hieraField.begin(); it != hieraField.end(); ++it)
           {
             (*it)->grid = gridTmp;
             (*it)->updateRef((*it)->grid);
           }
         }
       }
     }
   }

   void CField::updateRef(CGrid* grid)
   {
     if (!grid_ref.isEmpty()) grid_ref.setValue(grid->getId());
     else
     {
       std::vector<CAxis*> axisTmp = grid->getAxis();
       std::vector<CDomain*> domainTmp = grid->getDomains();
       if ((1<axisTmp.size()) || (1<domainTmp.size()))
         ERROR("void CField::updateRef(CGrid* grid)",
           << "More than one domain or axis is available for domain_ref/axis_ref of field " << this->getId());

       if ((!domain_ref.isEmpty()) && (domainTmp.empty()))
         ERROR("void CField::updateRef(CGrid* grid)",
           << "Incoherent between available domain and domain_ref of field " << this->getId());
       if ((!axis_ref.isEmpty()) && (axisTmp.empty()))
         ERROR("void CField::updateRef(CGrid* grid)",
           << "Incoherent between available axis and axis_ref of field " << this->getId());

       if (!domain_ref.isEmpty()) domain_ref.setValue(domainTmp[0]->getId());
       if (!axis_ref.isEmpty()) axis_ref.setValue(axisTmp[0]->getId());
     }
   }
   
   /*!
     Solve reference of all enabled fields even the source fields .
     In this step, we do transformations.
   */
   void CField::solveAllEnabledFieldsAndTransform()
   {
     CContext* context = CContext::getCurrent();
     bool hasClient = context->hasClient;
     bool hasServer = context->hasServer;

     if (!isReferenceSolvedAndTransformed)
     {
        isReferenceSolvedAndTransformed = true;

        if (hasClient && !hasServer)
        {
          solveRefInheritance(true);
          if (hasDirectFieldReference()) getDirectFieldReference()->solveAllEnabledFieldsAndTransform();
        }

        if (hasServer)
          solveServerOperation();

        solveGridReference();

        if (hasClient && !hasServer)
       {
         solveGenerateGrid();
         buildGridTransformationGraph();
       }

       solveGridDomainAxisRef(false);

       if (hasClient && !hasServer)
       {
         solveTransformedGrid();
       }

       solveGridDomainAxisRef(false);
     }
   }

   void CField::checkGridOfEnabledFields()
   {
      solveCheckMaskIndex(false);
   }

   void CField::sendGridOfEnabledFields()
   {
      solveGridDomainAxisRef(true);
      solveCheckMaskIndex(true);
   }


    void CField::solveOnlyReferenceEnabledField(bool doSending2Server)
   {
     CContext* context = CContext::getCurrent();
     if (!isReferenceSolved)
     {
        isReferenceSolved = true;

        if (context->hasClient && !context->hasServer)
//        if (context->hasClient)
        {
          solveRefInheritance(true);
          if (hasDirectFieldReference()) getDirectFieldReference()->solveOnlyReferenceEnabledField(false);
        }
//        else if (context->hasServer)
        if (context->hasServer)
          solveServerOperation();

        solveGridReference();

        if (context->hasClient && !context->hasServer)
//       if (context->hasClient)
       {
         solveGenerateGrid();
         buildGridTransformationGraph();
       }
     }
   }
     
   void CField::solveAllReferenceEnabledField(bool doSending2Server)
   {
     CContext* context = CContext::getCurrent();
     solveOnlyReferenceEnabledField(doSending2Server);

     if (!areAllReferenceSolved)
     {
        areAllReferenceSolved = true;

       // if (context->hasClient)
        if (context->hasClient && !context->hasServer)
        {
          solveRefInheritance(true);
          if (hasDirectFieldReference()) getDirectFieldReference()->solveAllReferenceEnabledField(false);
        }
       else if (context->hasServer)
        // if (context->hasServer && !context->hasClient)
          solveServerOperation();

        solveGridReference();
     }

     solveGridDomainAxisRef(doSending2Server);

     if (context->hasClient && !context->hasServer)
     {
       solveTransformedGrid();
     }

     solveCheckMaskIndex(doSending2Server);
   }

   std::map<int, StdSize> CField::getGridAttributesBufferSize()
   {
     return grid->getAttributesBufferSize();
   }

   std::vector<std::map<int, StdSize> > CField::getGridDataBufferSize()
   {
     return grid->getDataBufferSize(getId());
   }

   //----------------------------------------------------------------

   void CField::solveServerOperation(void)
   {
      CContext* context = CContext::getCurrent();

      if (!context->hasServer || !hasOutputFile) return;

      if (freq_op.isEmpty())
        freq_op.setValue(TimeStep);

      if (freq_offset.isEmpty())
        freq_offset.setValue(NoneDu);

      freq_operation_srv = file->output_freq.getValue();
      freq_write_srv     = file->output_freq.getValue();

      lastlast_Write_srv = context->getCalendar()->getInitDate();
      last_Write_srv     = context->getCalendar()->getInitDate();
      last_operation_srv = context->getCalendar()->getInitDate();

      const CDuration toffset = freq_operation_srv - freq_offset.getValue() - context->getCalendar()->getTimeStep();
      last_operation_srv     = last_operation_srv - toffset;

      if (operation.isEmpty())
        ERROR("void CField::solveServerOperation(void)",
              << "An operation must be defined for field \"" << getId() << "\".");

      boost::shared_ptr<func::CFunctor> functor;
      CArray<double, 1> dummyData;

#define DECLARE_FUNCTOR(MType, mtype) \
      if (operation.getValue().compare(#mtype) == 0) \
      { \
        functor.reset(new func::C##MType(dummyData)); \
      }

#include "functor_type.conf"

      if (!functor)
        ERROR("void CField::solveServerOperation(void)",
              << "\"" << operation << "\" is not a valid operation.");

      operationTimeType = functor->timeType();
   }

   //----------------------------------------------------------------

   /*!
    * Constructs the graph filter for the field, enabling or not the data output.
    * This method should not be called more than once with enableOutput equal to true.
    *
    * \param gc the garbage collector to use when building the filter graph
    * \param enableOutput must be true when the field data is to be
    *                     read by the client or/and written to a file
    */
   void CField::buildFilterGraph(CGarbageCollector& gc, bool enableOutput)
   {
     // if (!areAllReferenceSolved) solveAllReferenceEnabledField(false);
    if (!isReferenceSolvedAndTransformed) solveAllEnabledFieldsAndTransform();
     CContext* context = CContext::getCurrent();
     bool hasWriterServer = context->hasServer && !context->hasClient;
     bool hasIntermediateServer = context->hasServer && context->hasClient;

     if (hasWriterServer)
     {
        if (!instantDataFilter)
          instantDataFilter = clientSourceFilter = boost::shared_ptr<CSourceFilter>(new CSourceFilter(gc, grid));

             // If the field data is to be read by the client or/and written to a file
       if (enableOutput && !storeFilter && !fileWriterFilter)
       {
         if (file && (file->mode.isEmpty() || file->mode == CFile::mode_attr::write))
         {
           fileServerWriterFilter = boost::shared_ptr<CFileServerWriterFilter>(new CFileServerWriterFilter(gc, this));
           instantDataFilter->connectOutput(fileServerWriterFilter, 0);
         }
       }
     }
     else if (hasIntermediateServer)
     {
       if (!instantDataFilter)
         instantDataFilter = clientSourceFilter = boost::shared_ptr<CSourceFilter>(new CSourceFilter(gc, grid));

             // If the field data is to be read by the client or/and written to a file
       if (enableOutput && !storeFilter && !fileWriterFilter)
       {
         if (file && (file->mode.isEmpty() || file->mode == CFile::mode_attr::write))
         {
           fileWriterFilter = boost::shared_ptr<CFileWriterFilter>(new CFileWriterFilter(gc, this));
           instantDataFilter->connectOutput(fileWriterFilter, 0);
         }
       }
     }
     else
     {
       // Start by building a filter which can provide the field's instant data
       if (!instantDataFilter)
       {
         // Check if we have an expression to parse
       if (hasExpression())
         {
         boost::scoped_ptr<IFilterExprNode> expr(parseExpr(getExpression() + '\0'));
         boost::shared_ptr<COutputPin> filter = expr->reduce(gc, *this);

         // Check if a spatial transformation is needed
         if (!field_ref.isEmpty())
         {
           CGrid* gridRef = CField::get(field_ref)->grid;

           if (grid && grid != gridRef && grid->hasTransform())
           {
             double defaultValue = !default_value.isEmpty() ? default_value : 0.0;
             std::pair<boost::shared_ptr<CFilter>, boost::shared_ptr<CFilter> > filters = CSpatialTransformFilter::buildFilterGraph(gc, gridRef, grid, defaultValue);

             filter->connectOutput(filters.first, 0);
             filter = filters.second;
           }
         }

         instantDataFilter = filter;
         }
         // Check if we have a reference on another field
         else if (!field_ref.isEmpty())
           instantDataFilter = getFieldReference(gc);
         // Check if the data is to be read from a file
         else if (file && !file->mode.isEmpty() && file->mode == CFile::mode_attr::read)
         instantDataFilter = serverSourceFilter = boost::shared_ptr<CSourceFilter>(new CSourceFilter(gc, grid,
                                                                                                     freq_offset.isEmpty() ? NoneDu : freq_offset,
                                                                                                     true));
         else // The data might be passed from the model
         instantDataFilter = clientSourceFilter = boost::shared_ptr<CSourceFilter>(new CSourceFilter(gc, grid));
       }

       // If the field data is to be read by the client or/and written to a file
       if (enableOutput && !storeFilter && !fileWriterFilter)
       {
         if (!read_access.isEmpty() && read_access)
         {
           storeFilter = boost::shared_ptr<CStoreFilter>(new CStoreFilter(gc, CContext::getCurrent(), grid));
           instantDataFilter->connectOutput(storeFilter, 0);
         }

         if (file && (file->mode.isEmpty() || file->mode == CFile::mode_attr::write))
         {
           fileWriterFilter = boost::shared_ptr<CFileWriterFilter>(new CFileWriterFilter(gc, this));
           getTemporalDataFilter(gc, file->output_freq)->connectOutput(fileWriterFilter, 0);
         }
       }
     }
   }


   /*!
    * Returns the filter needed to handle the field reference.
    * This method should only be called when building the filter graph corresponding to the field.
    *
    * \param gc the garbage collector to use
    * \return the output pin corresponding to the field reference
    */
     boost::shared_ptr<COutputPin> CField::getFieldReference(CGarbageCollector& gc)
     {
       if (instantDataFilter || field_ref.isEmpty())
         ERROR("COutputPin* CField::getFieldReference(CGarbageCollector& gc)",
               "Impossible to get the field reference for a field which has already been parsed or which does not have a field_ref.");

       CField* fieldRef = CField::get(field_ref);
       fieldRef->buildFilterGraph(gc, false);

       std::pair<boost::shared_ptr<CFilter>, boost::shared_ptr<CFilter> > filters;
       // Check if a spatial transformation is needed
       if (grid && grid != fieldRef->grid && grid->hasTransform())
       {
         double defaultValue = !default_value.isEmpty() ? default_value : 0.0;
         filters = CSpatialTransformFilter::buildFilterGraph(gc, fieldRef->grid, grid, defaultValue);
       }
       else
         filters.first = filters.second = boost::shared_ptr<CFilter>(new CPassThroughFilter(gc));

       fieldRef->getInstantDataFilter()->connectOutput(filters.first, 0);

       return filters.second;
     }

   /*!
    * Returns the filter needed to handle a self reference in the field's expression.
    * If the needed filter does not exist, it is created, otherwise it is reused.
    * This method should only be called when building the filter graph corresponding
    * to the field's expression.
    *
    * \param gc the garbage collector to use
    * \return the output pin corresponding to a self reference
    */
   boost::shared_ptr<COutputPin> CField::getSelfReference(CGarbageCollector& gc)
   {
     if (instantDataFilter || !hasExpression())
       ERROR("COutputPin* CField::getSelfReference(CGarbageCollector& gc)",
             "Impossible to add a self reference to a field which has already been parsed or which does not have an expression.");

     if (!selfReferenceFilter)
     {
       if (file && !file->mode.isEmpty() && file->mode == CFile::mode_attr::read)
       {
         if (!serverSourceFilter)
           serverSourceFilter = boost::shared_ptr<CSourceFilter>(new CSourceFilter(gc, grid,
                                                                                   freq_offset.isEmpty() ? NoneDu : freq_offset,
                                                                                   true));
         selfReferenceFilter = serverSourceFilter;
       }
       else if (!field_ref.isEmpty())
       {
         CField* fieldRef = CField::get(field_ref);
         fieldRef->buildFilterGraph(gc, false);
         selfReferenceFilter = fieldRef->getInstantDataFilter();
       }
       else
       {
         if (!clientSourceFilter)
           clientSourceFilter = boost::shared_ptr<CSourceFilter>(new CSourceFilter(gc, grid));

         selfReferenceFilter = clientSourceFilter;
       }
     }

     return selfReferenceFilter;
   }

   /*!
    * Returns the temporal filter corresponding to the field's temporal operation
    * for the specified operation frequency. The filter is created if it does not
    * exist, otherwise it is reused.
    *
    * \param gc the garbage collector to use
    * \param outFreq the operation frequency, i.e. the frequency at which the output data will be computed
    * \return the output pin corresponding to the requested temporal filter
    */
   boost::shared_ptr<COutputPin> CField::getTemporalDataFilter(CGarbageCollector& gc, CDuration outFreq)
   {
     std::map<CDuration, boost::shared_ptr<COutputPin> >::iterator it = temporalDataFilters.find(outFreq);

     if (it == temporalDataFilters.end())
     {
       if (operation.isEmpty())
         ERROR("void CField::getTemporalDataFilter(CGarbageCollector& gc, CDuration outFreq)",
               << "An operation must be defined for field \"" << getId() << "\".");

       if (freq_op.isEmpty())
         freq_op.setValue(TimeStep);
       if (freq_offset.isEmpty())
         freq_offset.setValue(NoneDu);

       const bool ignoreMissingValue = (!detect_missing_value.isEmpty() && !default_value.isEmpty() && detect_missing_value == true);

       boost::shared_ptr<CTemporalFilter> temporalFilter(new CTemporalFilter(gc, operation,
                                                                             CContext::getCurrent()->getCalendar()->getInitDate(),
                                                                             freq_op, freq_offset, outFreq,
                                                                             ignoreMissingValue, ignoreMissingValue ? default_value : 0.0));
       instantDataFilter->connectOutput(temporalFilter, 0);

       it = temporalDataFilters.insert(std::make_pair(outFreq, temporalFilter)).first;
     }

     return it->second;
   }

   //----------------------------------------------------------------
/*
   void CField::fromBinary(StdIStream& is)
   {
      SuperClass::fromBinary(is);
#define CLEAR_ATT(name_)\
      SuperClassAttribute::operator[](#name_)->reset()

         CLEAR_ATT(domain_ref);
         CLEAR_ATT(axis_ref);
#undef CLEAR_ATT

   }
*/
   //----------------------------------------------------------------

   void CField::solveGridReference(void)
   {
      if (grid_ref.isEmpty() && domain_ref.isEmpty() && axis_ref.isEmpty() && scalar_ref.isEmpty())
      {
        ERROR("CField::solveGridReference(void)",
              << "A grid must be defined for field '" << getFieldOutputName() << "' .");
      }
      else if (!grid_ref.isEmpty() && (!domain_ref.isEmpty() || !axis_ref.isEmpty() || !scalar_ref.isEmpty()))
      {
        ERROR("CField::solveGridReference(void)",
              << "Field '" << getFieldOutputName() << "' has both a grid and a domain/axis/scalar." << std::endl
              << "Please define either 'grid_ref' or 'domain_ref'/'axis_ref'/'scalar_ref'.");
      }

      if (grid_ref.isEmpty())
      {
        std::vector<CDomain*> vecDom;
        std::vector<CAxis*> vecAxis;
        std::vector<CScalar*> vecScalar;
        std::vector<int> axisDomainOrderTmp;
        
        if (!domain_ref.isEmpty())
        {
          StdString tmp = domain_ref.getValue();
          if (CDomain::has(domain_ref))
          {
            vecDom.push_back(CDomain::get(domain_ref));
            axisDomainOrderTmp.push_back(2);
          }
          else
            ERROR("CField::solveGridReference(void)",
                  << "Invalid reference to domain '" << domain_ref.getValue() << "'.");
        }

        if (!axis_ref.isEmpty())
        {
          if (CAxis::has(axis_ref))
          {
            vecAxis.push_back(CAxis::get(axis_ref));
            axisDomainOrderTmp.push_back(1);
          }
          else
            ERROR("CField::solveGridReference(void)",
                  << "Invalid reference to axis '" << axis_ref.getValue() << "'.");
        }

        if (!scalar_ref.isEmpty())
        {
          if (CScalar::has(scalar_ref))
          {
            vecScalar.push_back(CScalar::get(scalar_ref));
            axisDomainOrderTmp.push_back(0);
          }
          else
            ERROR("CField::solveGridReference(void)",
                  << "Invalid reference to scalar '" << scalar_ref.getValue() << "'.");
        }
        
        CArray<int,1> axisDomainOrder(axisDomainOrderTmp.size());
        for (int idx = 0; idx < axisDomainOrderTmp.size(); ++idx)
        {
          axisDomainOrder(idx) = axisDomainOrderTmp[idx];
        }

        // Warning: the gridId shouldn't be set as the grid_ref since it could be inherited
        StdString gridId = CGrid::generateId(vecDom, vecAxis, vecScalar,axisDomainOrder);
        if (CGrid::has(gridId))
          this->grid = CGrid::get(gridId);
        else
          this->grid = CGrid::createGrid(gridId, vecDom, vecAxis, vecScalar,axisDomainOrder);
      }
      else
      {
        if (CGrid::has(grid_ref))
          this->grid = CGrid::get(grid_ref);
        else
          ERROR("CField::solveGridReference(void)",
                << "Invalid reference to grid '" << grid_ref.getValue() << "'.");
      }
   }

   void CField::solveGridDomainAxisRef(bool checkAtt)
   {
     grid->solveDomainAxisRef(checkAtt);
   }

   void CField::solveCheckMaskIndex(bool doSendingIndex)
   {
     grid->checkMaskIndex(doSendingIndex);
   }

   void CField::solveTransformedGrid()
   {
     if (grid && !grid->isTransformed() && hasDirectFieldReference() && grid != getDirectFieldReference()->grid)
     {
       std::vector<CGrid*> grids;
       // Source grid
       grids.push_back(getDirectFieldReference()->grid);
       // Intermediate grids
       if (!grid_path.isEmpty())
       {
         std::string gridId;
         size_t start = 0, end;

         do
         {
           end = grid_path.getValue().find(',', start);
           if (end != std::string::npos)
           {
             gridId = grid_path.getValue().substr(start, end - start);
             start = end + 1;
           }
           else
             gridId = grid_path.getValue().substr(start);

           if (!CGrid::has(gridId))
             ERROR("void CField::solveTransformedGrid()",
                   << "Invalid grid_path, the grid '" << gridId << "' does not exist.");

           grids.push_back(CGrid::get(gridId));
         }
         while (end != std::string::npos);
       }
       // Destination grid
       grids.push_back(grid);

       for (size_t i = 0, count = grids.size() - 1; i < count; ++i)
       {
         CGrid *gridSrc  = grids[i];
         CGrid *gridDest = grids[i + 1];
         if (!gridDest->isTransformed())
           gridDest->transformGrid(gridSrc);
       }
     }
     else if (grid && grid->hasTransform() && !grid->isTransformed())
     {
       // Temporarily deactivate the self-transformation of grid
       //grid->transformGrid(grid);
     }
   }

   void CField::solveGenerateGrid()
   {
     if (grid && !grid->isTransformed() && hasDirectFieldReference() && grid != getDirectFieldReference()->grid)
       grid->completeGrid(getDirectFieldReference()->grid);
     else
       grid->completeGrid();
   }

   void CField::solveGridDomainAxisBaseRef()
   {
     grid->solveDomainAxisRef(false);
     grid->solveDomainAxisBaseRef();
   }

   ///-------------------------------------------------------------------

   template <>
   void CGroupTemplate<CField, CFieldGroup, CFieldAttributes>::solveRefInheritance(void)
   {
      if (this->group_ref.isEmpty()) return;
      StdString gref = this->group_ref.getValue();

      if (!CFieldGroup::has(gref))
         ERROR("CGroupTemplate<CField, CFieldGroup, CFieldAttributes>::solveRefInheritance(void)",
               << "[ gref = " << gref << "]"
               << " invalid group name !");

      CFieldGroup* group = CFieldGroup::get(gref);
      CFieldGroup* owner = CFieldGroup::get(boost::polymorphic_downcast<CFieldGroup*>(this));

      std::vector<CField*> allChildren  = group->getAllChildren();
      std::vector<CField*>::iterator it = allChildren.begin(), end = allChildren.end();

      for (; it != end; it++)
      {
         CField* child = *it;
         if (child->hasId()) owner->createChild()->field_ref.setValue(child->getId());

      }
   }

   void CField::scaleFactorAddOffset(double scaleFactor, double addOffset)
   {
     // map<int, CArray<double,1> >::iterator it;
     // for (it = data_srv.begin(); it != data_srv.end(); it++) it->second = (it->second - addOffset) / scaleFactor;
     recvDataSrv = (recvDataSrv - addOffset) / scaleFactor;
   }

   void CField::invertScaleFactorAddOffset(double scaleFactor, double addOffset)
   {
     // map<int, CArray<double,1> >::iterator it;
     // for (it = data_srv.begin(); it != data_srv.end(); it++) it->second = it->second * scaleFactor + addOffset;
     recvDataSrv = recvDataSrv * scaleFactor + addOffset;
   }

   void CField::outputField(CArray<double,1>& fieldOut)
   { 
      CArray<size_t,1>& outIndexClient = grid->localIndexToWriteOnClient;
      CArray<size_t,1>& outIndexServer = grid->localIndexToWriteOnServer;
      for (size_t idx = 0; idx < outIndexServer.numElements(); ++idx)
      {
        fieldOut(outIndexServer(idx)) = recvDataSrv(outIndexClient(idx));
      }
   }

   void CField::inputField(CArray<double,1>& fieldIn)
   {
      // map<int, CArray<double,1> >::iterator it;
      // for (it = data_srv.begin(); it != data_srv.end(); it++)
      // {
      //    grid->inputField(it->first, fieldOut.dataFirst(), it->second);
      // }
      CArray<size_t,1>& outIndexClient = grid->localIndexToWriteOnClient;
      CArray<size_t,1>& outIndexServer = grid->localIndexToWriteOnServer;
      for (size_t idx = 0; idx < outIndexServer.numElements(); ++idx)
      {
        recvDataSrv(outIndexClient(idx)) = fieldIn(outIndexServer(idx));
      }

   }

   void CField::outputCompressedField(CArray<double,1>& fieldOut)
   {
      map<int, CArray<double,1> >::iterator it;

      for (it = data_srv.begin(); it != data_srv.end(); it++)
      {
         grid->outputCompressedField(it->first, it->second, fieldOut.dataFirst());
      }
   }

   ///-------------------------------------------------------------------

   void CField::parse(xml::CXMLNode& node)
   {
      SuperClass::parse(node);
      if (!node.getContent(this->content))
      {
        if (node.goToChildElement())
        {
          do
          {
            if (node.getElementName() == "variable" || node.getElementName() == "variable_group") this->getVirtualVariableGroup()->parseChild(node);
          } while (node.goToNextElement());
          node.goToParentElement();
        }
      }
    }

   /*!
     This function retrieves Id of corresponding domain_ref and axis_ref (if any)
   of a field. In some cases, only domain exists but axis doesn't
   \return pair of Domain and Axis id
   */
   const std::vector<StdString>& CField::getRefDomainAxisIds()
   {
     CGrid* cgPtr = getRelGrid();
     if (NULL != cgPtr)
     {
       std::vector<StdString>::iterator it;
       if (!domain_ref.isEmpty())
       {
         std::vector<StdString> domainList = cgPtr->getDomainList();
         it = std::find(domainList.begin(), domainList.end(), domain_ref.getValue());
         if (domainList.end() != it) domAxisScalarIds_[0] = *it;
       }

       if (!axis_ref.isEmpty())
       {
         std::vector<StdString> axisList = cgPtr->getAxisList();
         it = std::find(axisList.begin(), axisList.end(), axis_ref.getValue());
         if (axisList.end() != it) domAxisScalarIds_[1] = *it;
       }

       if (!scalar_ref.isEmpty())
       {
         std::vector<StdString> scalarList = cgPtr->getScalarList();
         it = std::find(scalarList.begin(), scalarList.end(), scalar_ref.getValue());
         if (scalarList.end() != it) domAxisScalarIds_[2] = *it;
       }
     }
     return (domAxisScalarIds_);
   }

   CVariable* CField::addVariable(const string& id)
   {
     return vVariableGroup->createChild(id);
   }

   CVariableGroup* CField::addVariableGroup(const string& id)
   {
     return vVariableGroup->createChildGroup(id);
   }

   void CField::sendAddAllVariables()
   {
     std::vector<CVariable*> allVar = getAllVariables();
     std::vector<CVariable*>::const_iterator it = allVar.begin();
     std::vector<CVariable*>::const_iterator itE = allVar.end();

     for (; it != itE; ++it)
     {
       this->sendAddVariable((*it)->getId());
       (*it)->sendAllAttributesToServer();
       (*it)->sendValue();
     }
   }

   void CField::sendAddAllVariables(CContextClient* client)
   {
     std::vector<CVariable*> allVar = getAllVariables();
     std::vector<CVariable*>::const_iterator it = allVar.begin();
     std::vector<CVariable*>::const_iterator itE = allVar.end();

     for (; it != itE; ++it)
     {
       this->sendAddVariable((*it)->getId(), client);
       (*it)->sendAllAttributesToServer(client);
       (*it)->sendValue(client);
     }
   }

   void CField::sendAddVariable(const string& id)
   {
      sendAddItem(id, (int)EVENT_ID_ADD_VARIABLE);
   }

   void CField::sendAddVariable(const string& id, CContextClient* client)
   {
      sendAddItem(id, (int)EVENT_ID_ADD_VARIABLE, client);
   }

   void CField::sendAddVariableGroup(const string& id)
   {
      sendAddItem(id, (int)EVENT_ID_ADD_VARIABLE_GROUP);
   }

   void CField::recvAddVariable(CEventServer& event)
   {

      CBufferIn* buffer = event.subEvents.begin()->buffer;
      string id;
      *buffer >> id;
      get(id)->recvAddVariable(*buffer);
   }

   void CField::recvAddVariable(CBufferIn& buffer)
   {
      string id;
      buffer >> id;
      addVariable(id);
   }

   void CField::recvAddVariableGroup(CEventServer& event)
   {

      CBufferIn* buffer = event.subEvents.begin()->buffer;
      string id;
      *buffer >> id;
      get(id)->recvAddVariableGroup(*buffer);
   }

   void CField::recvAddVariableGroup(CBufferIn& buffer)
   {
      string id;
      buffer >> id;
      addVariableGroup(id);
   }

   /*!
    * Returns string arithmetic expression associated to the field.
    * \return if content is defined return content string, otherwise, if "expr" attribute is defined, return expr string.
    */
   const string& CField::getExpression(void)
   {
     if (!expr.isEmpty() && content.empty())
     {
       content = expr;
       expr.reset();
     }

     return content;
   }

   bool CField::hasExpression(void) const
   {
     return (!expr.isEmpty() || !content.empty());
   }


   DEFINE_REF_FUNC(Field,field)
} // namespace xios