ENH: support enumerations for vtk xml file tags and some legacy text elements

src/fileFormats/Make/files

@@ -26,6 +26,7 @@ vtk/format/foamVtkLegacyRawFormatter.C
 vtk/output/foamVtkOutput.C
 vtk/output/foamVtkOutputOptions.C
 vtk/read/vtkUnstructuredReader.C
+vtk/type/foamVtkFileEnums.C
 vtk/type/foamVtkPTraits.C
 
 coordSet/coordSet.C

src/fileFormats/vtk/format/foamVtkFormatter.C

@@ -24,16 +24,6 @@ License
 
 #include "foamVtkFormatter.H"
 
-// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
-
-Foam::foamVtkOutput::formatter::formatter(std::ostream& os)
-:
-    os_(os),
-    xmlTags_(),
-    inTag_(false)
-{}
-
-
 // * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
 
 Foam::foamVtkOutput::formatter::~formatter()
@@ -92,19 +82,20 @@ Foam::foamVtkOutput::formatter::comment(const std::string& text)
 
 
 Foam::foamVtkOutput::formatter&
-Foam::foamVtkOutput::formatter::openTag(const word& tag)
+Foam::foamVtkOutput::formatter::openTag(const word& tagName)
 {
     if (inTag_)
     {
         WarningInFunction
-            << "open XML tag '" << tag << "', but already within a tag!"
+            << "open XML tag '" << tagName
+            << "', but already within a tag!"
             << endl;
     }
 
     indent();
-    os_ << '<' << tag;
+    os_ << '<' << tagName;
 
-    xmlTags_.push(tag);
+    xmlTags_.push(tagName);
     inTag_ = true;
 
     return *this;
@@ -136,7 +127,7 @@ Foam::foamVtkOutput::formatter::closeTag(const bool isEmpty)
 
 
 Foam::foamVtkOutput::formatter&
-Foam::foamVtkOutput::formatter::endTag(const word& tag)
+Foam::foamVtkOutput::formatter::endTag(const word& tagName)
 {
     const word curr = xmlTags_.pop();
     indent();
@@ -150,10 +141,10 @@ Foam::foamVtkOutput::formatter::endTag(const word& tag)
     }
 
     // verify inTag_
-    if (!tag.empty() && tag != curr)
+    if (!tagName.empty() && tagName != curr)
     {
         WarningInFunction
-            << "expected to end xml-tag '" << tag
+            << "expected to end xml-tag '" << tagName
             << "' but found '" << curr << "' instead"
             << endl;
     }
@@ -166,16 +157,6 @@ Foam::foamVtkOutput::formatter::endTag(const word& tag)
 }
 
 
-Foam::foamVtkOutput::formatter&
-Foam::foamVtkOutput::formatter::tag(const word& tag)
-{
-    openTag(tag);
-    closeTag();
-
-    return *this;
-}
-
-
 Foam::foamVtkOutput::formatter&
 Foam::foamVtkOutput::formatter::beginVTKFile
 (
@@ -184,7 +165,7 @@ Foam::foamVtkOutput::formatter::beginVTKFile
     const bool leaveOpen
 )
 {
-    openTag("VTKFile");
+    openTag(vtkFileTag::VTK_FILE);
     xmlAttr("type",        contentType);
     xmlAttr("version",     contentVersion);
     xmlAttr("byte_order",  foamVtkPTraits<Foam::endian>::typeName);
@@ -234,89 +215,4 @@ Foam::foamVtkOutput::formatter::xmlAttr
 }
 
 
-Foam::foamVtkOutput::formatter&
-Foam::foamVtkOutput::formatter::xmlAttr
-(
-    const word& k,
-    const int32_t v,
-    const char quote
-)
-{
-    return xmlAttribute(k, v, quote);
-}
-
-
-Foam::foamVtkOutput::formatter&
-Foam::foamVtkOutput::formatter::xmlAttr
-(
-    const word& k,
-    const int64_t v,
-    const char quote
-)
-{
-    return xmlAttribute(k, v, quote);
-}
-
-
-Foam::foamVtkOutput::formatter&
-Foam::foamVtkOutput::formatter::xmlAttr
-(
-    const word& k,
-    const uint64_t v,
-    const char quote
-)
-{
-    return xmlAttribute(k, v, quote);
-}
-
-
-Foam::foamVtkOutput::formatter&
-Foam::foamVtkOutput::formatter::xmlAttr
-(
-    const word& k,
-    const scalar v,
-    const char quote
-)
-{
-    return xmlAttribute(k, v, quote);
-}
-
-
-// * * * * * * * * * * * * * * Member Operators * * * * * * * * * * * * * * //
-
-Foam::foamVtkOutput::formatter&
-Foam::foamVtkOutput::formatter::operator()(const word& k, const std::string& v)
-{
-    return xmlAttr(k, v);
-}
-
-
-Foam::foamVtkOutput::formatter&
-Foam::foamVtkOutput::formatter::operator()(const word& k, const int32_t v)
-{
-    return xmlAttr(k, v);
-}
-
-
-Foam::foamVtkOutput::formatter&
-Foam::foamVtkOutput::formatter::operator()(const word& k, const int64_t v)
-{
-    return xmlAttr(k, v);
-}
-
-
-Foam::foamVtkOutput::formatter&
-Foam::foamVtkOutput::formatter::operator()(const word& k, const uint64_t v)
-{
-    return xmlAttr(k, v);
-}
-
-
-Foam::foamVtkOutput::formatter&
-Foam::foamVtkOutput::formatter::operator()(const word& k, const scalar v)
-{
-    return xmlAttr(k, v);
-}
-
-
 // ************************************************************************* //

src/fileFormats/vtk/format/foamVtkFormatter.H

@@ -44,6 +44,7 @@ SourceFiles
 #include "word.H"
 #include "UList.H"
 #include "LIFOStack.H"
+#include "foamVtkFileEnums.H"
 #include "foamVtkPTraits.H"
 #include "foamVtkOutputTypes.H"
 
@@ -89,7 +90,7 @@ protected:
     // Protected Member Functions
 
         //- Construct and attach to an output stream
-        formatter(std::ostream& os);
+        inline formatter(std::ostream& os);
 
 public:
 
@@ -108,11 +109,7 @@ public:
       // Access
 
         //- Access to the underlying output stream
-        inline std::ostream& os()
+        inline std::ostream& os();
-        {
-            return os_;
-        }
-
 
         //- The output formatType.
         virtual enum formatType format() const = 0;
@@ -158,7 +155,11 @@ public:
 
         //- Open XML tag
         //  \return formatter for chaining
-        formatter& openTag(const word& tag);
+        formatter& openTag(const word& tagName);
+
+        //- Open XML tag
+        //  \return formatter for chaining
+        inline formatter& openTag(const vtkFileTag& tagEnum);
 
         //- Close XML tag, optional as an empty container.
         //  Always adds a trailing newline.
@@ -168,11 +169,20 @@ public:
         //- End XML tag, optional with sanity check
         //  Always adds a trailing newline.
         //  \return formatter for chaining
-        formatter& endTag(const word& tag = word::null);
+        formatter& endTag(const word& tagName = word::null);
+
+        //- End XML tag with sanity check
+        //  Always adds a trailing newline.
+        //  \return formatter for chaining
+        inline formatter& endTag(const vtkFileTag& tagEnum);
 
         //- Write XML tag without any attributes. Combines openTag/closeTag.
         //  \return formatter for chaining
-        formatter& tag(const word& tag);
+        inline formatter& tag(const word& tagName);
+
+        //- Write XML tag without any attributes. Combines openTag/closeTag.
+        //  \return formatter for chaining
+        inline formatter& tag(const vtkFileTag& tagEnum);
 
         //- Add a "VTKFile" XML tag for contentType, followed by a tag for
         //  the contentType itself. Optionally leave the contentType tag
@@ -206,26 +216,15 @@ public:
 
         //- End "DataArray" XML tag
         //  \return formatter for chaining
-        inline formatter& endDataArray()
+        inline formatter& endDataArray();
-        {
-            return endTag("DataArray");
-        }
 
         //- End "AppendedData" XML tag
         //  \return formatter for chaining
-        inline formatter& endAppendedData()
+        inline formatter& endAppendedData();
-        {
-            flush();     // flush any pending encoded content
-            os_ << '\n'; // clear separation from content.
-            return endTag("AppendedData");
-        }
 
         //- End "VTKFile" XML tag
         //  \return formatter for chaining
-        inline formatter& endVTKFile()
+        inline formatter& endVTKFile();
-        {
-            return endTag("VTKFile");
-        }
 
 
         //- Write XML attribute
@@ -239,7 +238,7 @@ public:
 
         //- Write XML attribute
         //  \return formatter for chaining
-        formatter& xmlAttr
+        inline formatter& xmlAttr
         (
             const word& k,
             const int32_t v,
@@ -248,7 +247,7 @@ public:
 
         //- Write XML attribute
         //  \return formatter for chaining
-        formatter& xmlAttr
+        inline formatter& xmlAttr
         (
             const word& k,
             const int64_t v,
@@ -257,7 +256,7 @@ public:
 
         //- Write XML attribute
         //  \return formatter for chaining
-        formatter& xmlAttr
+        inline formatter& xmlAttr
         (
             const word& k,
             const uint64_t v,
@@ -266,7 +265,7 @@ public:
 
         //- Write XML attribute
         //  \return formatter for chaining
-        formatter& xmlAttr
+        inline formatter& xmlAttr
         (
             const word& k,
             const scalar v,
@@ -278,23 +277,23 @@ public:
 
         //- Write XML attribute
         //  \return formatter for chaining
-        formatter& operator()(const word& k, const std::string& v);
+        inline formatter& operator()(const word& k, const std::string& v);
 
         //- Write XML attribute
         //  \return formatter for chaining
-        formatter& operator()(const word& k, const int32_t v);
+        inline formatter& operator()(const word& k, const int32_t v);
 
         //- Write XML attribute
         //  \return formatter for chaining
-        formatter& operator()(const word& k, const int64_t v);
+        inline formatter& operator()(const word& k, const int64_t v);
 
         //- Write XML attribute
         //  \return formatter for chaining
-        formatter& operator()(const word& k, const uint64_t v);
+        inline formatter& operator()(const word& k, const uint64_t v);
 
         //- Write XML attribute
         //  \return formatter for chaining
-        formatter& operator()(const word& k, const scalar v);
+        inline formatter& operator()(const word& k, const scalar v);
 
 };
 
@@ -306,6 +305,8 @@ public:
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
+#include "foamVtkFormatterI.H"
+
 #ifdef NoRepository
     #include "foamVtkFormatterTemplates.C"
 #endif

src/fileFormats/vtk/format/foamVtkFormatterI.H

@@ -0,0 +1,183 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2017 OpenCFD Ltd.
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
+
+inline Foam::foamVtkOutput::formatter::formatter(std::ostream& os)
+:
+    os_(os),
+    xmlTags_(),
+    inTag_(false)
+{}
+
+
+// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
+
+inline std::ostream& Foam::foamVtkOutput::formatter::os()
+{
+    return os_;
+}
+
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::openTag(const vtkFileTag& tagEnum)
+{
+    return openTag(vtkFileTagNames[tagEnum]);
+}
+
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::endTag(const vtkFileTag& tagEnum)
+{
+    return endTag(vtkFileTagNames[tagEnum]);
+}
+
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::tag(const word& tagName)
+{
+    openTag(tagName);
+    closeTag();
+
+    return *this;
+}
+
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::tag(const vtkFileTag& tagEnum)
+{
+    return tag(vtkFileTagNames[tagEnum]);
+}
+
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::endDataArray()
+{
+    return endTag("DataArray");
+}
+
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::endAppendedData()
+{
+    flush();     // flush any pending encoded content
+    os_ << '\n'; // clear separation from content.
+    return endTag("AppendedData");
+}
+
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::endVTKFile()
+{
+    return endTag(vtkFileTag::VTK_FILE);
+}
+
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::xmlAttr
+(
+    const word& k,
+    const int32_t v,
+    const char quote
+)
+{
+    return xmlAttribute(k, v, quote);
+}
+
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::xmlAttr
+(
+    const word& k,
+    const int64_t v,
+    const char quote
+)
+{
+    return xmlAttribute(k, v, quote);
+}
+
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::xmlAttr
+(
+    const word& k,
+    const uint64_t v,
+    const char quote
+)
+{
+    return xmlAttribute(k, v, quote);
+}
+
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::xmlAttr
+(
+    const word& k,
+    const scalar v,
+    const char quote
+)
+{
+    return xmlAttribute(k, v, quote);
+}
+
+
+// * * * * * * * * * * * * * * Member Operators * * * * * * * * * * * * * * //
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::operator()(const word& k, const std::string& v)
+{
+    return xmlAttr(k, v);
+}
+
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::operator()(const word& k, const int32_t v)
+{
+    return xmlAttr(k, v);
+}
+
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::operator()(const word& k, const int64_t v)
+{
+    return xmlAttr(k, v);
+}
+
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::operator()(const word& k, const uint64_t v)
+{
+    return xmlAttr(k, v);
+}
+
+
+inline Foam::foamVtkOutput::formatter&
+Foam::foamVtkOutput::formatter::operator()(const word& k, const scalar v)
+{
+    return xmlAttr(k, v);
+}
+
+
+// ************************************************************************* //

src/fileFormats/vtk/output/foamVtkOutput.C

@@ -36,7 +36,24 @@ License
 
 // * * * * * * * * * * * * * * * Static Data * * * * * * * * * * * * * * * * //
 
-const Foam::word Foam::foamVtkOutput::legacy::EXT = "vtk";
+const Foam::Enum<Foam::foamVtkOutput::legacy::textElemType>
+Foam::foamVtkOutput::legacy::textNames
+{
+    { textElemType::POINTS,            "POINTS" },
+    { textElemType::CELLS,             "CELLS" },
+    { textElemType::POLYS,             "POLYGONS" },
+    { textElemType::VERTS,             "VERTICES" },
+    { textElemType::POLY_DATA,         "POLYDATA" },
+    { textElemType::UNSTRUCTURED_GRID, "UNSTRUCTURED_GRID" },
+};
+
+
+const Foam::Enum<Foam::vtkFileTag>
+Foam::foamVtkOutput::legacy::dataTypeNames
+{
+    { vtkFileTag::CELL_DATA,  "CELL_DATA" },
+    { vtkFileTag::POINT_DATA, "POINT_DATA" }
+};
 
 
 // * * * * * * * * * * * * * * Global Functions  * * * * * * * * * * * * * * //
@@ -99,7 +116,7 @@ Foam::label Foam::foamVtkOutput::writeVtmFile
     forAll(files, i)
     {
         vtmFile
-            .openTag("DataSet")
+            .openTag(vtkFileTag::DATA_SET)
             ( "index", i )
             ( "file", files[i] )
             .closeTag(true);
@@ -136,31 +153,40 @@ std::ostream& Foam::foamVtkOutput::legacy::fileHeader
 }
 
 
-std::ostream& Foam::foamVtkOutput::legacy::cellDataHeader
+std::ostream& Foam::foamVtkOutput::legacy::dataHeader
 (
     std::ostream& os,
-    const label nCells,
+    const vtkFileTag& dataTypeTag,
+    const label nEntries,
     const label nFields
 )
 {
-    os  << "CELL_DATA " << nCells << nl
+    os  << dataTypeNames[dataTypeTag] << ' ' << nEntries << nl
         << "FIELD attributes " << nFields << nl;
 
     return os;
 }
 
 
+std::ostream& Foam::foamVtkOutput::legacy::cellDataHeader
+(
+    std::ostream& os,
+    const label nEntries,
+    const label nFields
+)
+{
+    return dataHeader(os, vtkFileTag::CELL_DATA, nEntries, nFields);
+}
+
+
 std::ostream& Foam::foamVtkOutput::legacy::pointDataHeader
 (
     std::ostream& os,
-    const label nPoints,
+    const label nEntries,
     const label nFields
 )
 {
-    os  << "POINT_DATA " << nPoints << nl
+    return dataHeader(os, vtkFileTag::POINT_DATA, nEntries, nFields);
-        << "FIELD attributes " << nFields << nl;
-
-    return os;
 }
 
 

src/fileFormats/vtk/output/foamVtkOutput.H

@@ -44,6 +44,7 @@ SourceFiles
 #define foamVtkOutput_H
 
 #include "autoPtr.H"
+#include "Enum.H"
 #include "foamVtkOutputTypes.H"
 #include "foamVtkFormatter.H"
 #include "floatScalar.H"
@@ -120,10 +121,22 @@ namespace foamVtkOutput
 //- Some minimal additional support for writing legacy files
 namespace legacy
 {
-  // Constants
+    //- Some standard text elements for legacy vtk files
+    enum class textElemType
+    {
+        POINTS,             //!< "POINTS"
+        CELLS,              //!< "CELLS"
+        POLYS,              //!< "POLYGONS"
+        VERTS,              //!< "VERTICES"
+        POLY_DATA,          //!< "POLYDATA"
+        UNSTRUCTURED_GRID,  //!< "UNSTRUCTURED_GRID"
+    };
 
-    //- File extension for legacy files (vtk)
+    //- Strings corresponding to the elements
-    extern const Foam::word EXT;
+    extern const Foam::Enum<textElemType> textNames;
+
+    //- Strings corresponding to the elements
+    extern const Foam::Enum<vtkFileTag>   dataTypeNames;
 
 
   // Functions
@@ -145,20 +158,34 @@ namespace legacy
         const std::string& title
     );
 
-    //- Emit header for legacy CELL_DATA
+
-    std::ostream& cellDataHeader
+    //- Emit header for legacy CELL_DATA or POINT_DATA, corresponding to the
+    //  enumeration textElemType::CELLS or textElemType::POINTS, respectively.
+    //  The nEntries corresponds similarly to the number of cells or points,
+    //  respectively.
+    std::ostream& dataHeader
     (
         std::ostream& os,
-        const label nCells,
+        const vtkFileTag& dataTypeTag,
+        const label nEntries,
         const label nFields
     );
 
+    //- Emit header for legacy CELL_DATA.
+    //  The nEntries should normally correspond to the number of cells.
+    std::ostream& cellDataHeader
+    (
+        std::ostream& os,
+        const label nEntries,
+        const label nFields
+    );
 
     //- Emit header for legacy POINT_DATA
+    //  The nEntries should normally correspond to the number of points.
     std::ostream& pointDataHeader
     (
         std::ostream& os,
-        const label nPoints,
+        const label nEntries,
         const label nFields
     );
 

src/fileFormats/vtk/type/foamVtkFileEnums.C

@@ -0,0 +1,64 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2017 OpenCFD Ltd.
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+\*---------------------------------------------------------------------------*/
+
+#include "foamVtkFileEnums.H"
+#include "Enum.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+const Foam::Enum<Foam::vtkFileTag> Foam::vtkFileTagNames
+(
+    vtkFileTag::VTK_FILE,
+    {
+        "VTKFile",
+        "DataArray",
+        "Piece",
+        "DataSet",
+        "Points",
+        "Cells",
+        "Polys",
+        "Verts",
+        "CellData",
+        "PointData",
+        "PolyData",
+        "UnstructuredGrid",
+    }
+);
+
+
+const Foam::Enum<Foam::vtkFileAttr> Foam::vtkFileAttrNames
+(
+    vtkFileAttr::OFFSET,
+    {
+        "offset",
+        "NumberOfPoints",
+        "NumberOfCells",
+        "NumberOfPolys",
+        "NumberOfVerts"
+    }
+);
+
+
+// ************************************************************************* //

src/fileFormats/vtk/type/foamVtkFileEnums.H

@@ -0,0 +1,90 @@
+/*---------------------------------------------------------------------------*\
+  =========                 |
+  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
+   \\    /   O peration     |
+    \\  /    A nd           | Copyright (C) 2017 OpenCFD Ltd.
+     \\/     M anipulation  |
+-------------------------------------------------------------------------------
+License
+    This file is part of OpenFOAM.
+
+    OpenFOAM is free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+    for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
+
+InNamespace
+    Foam::foam
+
+Description
+    Enumerations for commonly used VTK file items.
+
+SourceFiles
+    foamVtkFileEnums.C
+
+\*---------------------------------------------------------------------------*/
+
+#ifndef foamVtkFileEnums_H
+#define foamVtkFileEnums_H
+
+#include "Enum.H"
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+namespace Foam
+{
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+//- Some common XML tags for vtk files
+enum class vtkFileTag
+{
+    VTK_FILE,           //!< "VTKFile"
+    DATA_ARRAY,         //!< "DataArray"
+    PIECE,              //!< "Piece"
+    DATA_SET,           //!< "DataSet"
+    POINTS,             //!< "Points"
+    CELLS,              //!< "Cells"
+    POLYS,              //!< "Polys"
+    VERTS,              //!< "Verts"
+    CELL_DATA,          //!< "CellData"
+    POINT_DATA,         //!< "PointData"
+    POLY_DATA,          //!< "PolyData"
+    UNSTRUCTURED_GRID,  //!< "UnstructuredGrid"
+};
+
+//- Strings corresponding to the elements
+extern const Foam::Enum<vtkFileTag> vtkFileTagNames;
+
+
+//- Some common XML attributes for vtk files
+enum class vtkFileAttr
+{
+    OFFSET,             //!< "offset"
+    NUMBER_OF_POINTS,   //!< "NumberOfPoints"
+    NUMBER_OF_CELLS,    //!< "NumberOfCells"
+    NUMBER_OF_POLYS,    //!< "NumberOfPolys"
+    NUMBER_OF_VERTS,    //!< "NumberOfVerts"
+};
+
+//- Strings corresponding to the elements
+extern const Foam::Enum<vtkFileAttr> vtkFileAttrNames;
+
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+} // End namespace Foam
+
+// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
+
+#endif
+
+// ************************************************************************* //