# AttachAttributes

VTKExamples/Cxx/PolyData/AttachAttributes

### Code

AttachAttributes.cxx

    // vtk includes
    #include <vtkDoubleArray.h>
    #include <vtkInformation.h>
    #include <vtkInformationDoubleVectorKey.h>

    // std includes
    #include <iostream>

    int main(int, char *[]) {

      // create a 2-element array
      vtkDoubleArray* array = vtkDoubleArray::New();
      array->SetName("array");
      array->SetNumberOfComponents(1);
      array->SetNumberOfTuples(2);
      array->SetValue(0, 1.);
      array->SetValue(1, 2.);

      // access the info (presently none stored)
      vtkInformation* info = array->GetInformation();

      // add one attribute, a double vector
      const char *name = "myKey";
      const char *location = "MyClass"; //
      const int length = 3;
      vtkInformationDoubleVectorKey *key = new vtkInformationDoubleVectorKey(name,
                                                                             location,
                                                                             length);
      double values[] = {0.1, 0.2, 0.3};
      info->Set(key, values[0], values[1],values[2]);

      // extract the key
      double *vals = info->Get(key);
      std::cout << "extracted values are: " << vals[0] << ", " << vals[1] << ", " << vals[2] << '\n';
      array->Delete();
      // array->Delete will also delete key (do not call delete key)

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(AttachAttributes)

    find_package(VTK REQUIRED)
    include(${VTK_USE_FILE})

    add_executable(AttachAttributes MACOSX_BUNDLE AttachAttributes.cxx)

    target_link_libraries(AttachAttributes ${VTK_LIBRARIES})

### Download and Build AttachAttributes

Danger

The generation of tar files has not been ported to the new VTKExamples. Some tarballs may be missing or out-of-date.

Click here to download AttachAttributes and its CMakeLists.txt file. Once the tarball AttachAttributes.tar has been downloaded and extracted,

    cd AttachAttributes/build

If VTK is installed:

    cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

    cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

    make

and run it:

    ./AttachAttributes

WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.