# vtkTestGraphAlgorithmSource

VTKExamples/Cxx/Developers/vtkTestGraphAlgorithmSource

### Code

vtkTestGraphAlgorithmSource.cxx

    #include "vtkTestGraphAlgorithmSource.h"

    #include "vtkObjectFactory.h"
    #include "vtkStreamingDemandDrivenPipeline.h"
    #include "vtkInformationVector.h"
    #include "vtkInformation.h"
    #include "vtkDataObject.h"
    #include "vtkSmartPointer.h"
    #include "vtkMutableUndirectedGraph.h"
    #include "vtkUndirectedGraph.h"
    #include "vtkGraph.h"

    vtkStandardNewMacro(vtkTestGraphAlgorithmSource);

    vtkTestGraphAlgorithmSource::vtkTestGraphAlgorithmSource()
    {
      this->SetNumberOfInputPorts(0);
      this->SetNumberOfOutputPorts(1);
    }

    vtkTestGraphAlgorithmSource::~vtkTestGraphAlgorithmSource()
    {

    }

    int vtkTestGraphAlgorithmSource::RequestData(
      vtkInformation *vtkNotUsed(request),
      vtkInformationVector **vtkNotUsed(inputVector),
      vtkInformationVector *outputVector)
    {

      vtkInformation *outInfo = outputVector->GetInformationObject(0);

      vtkGraph *output = vtkGraph::SafeDownCast(
        outInfo->Get(vtkDataObject::DATA_OBJECT()));

      vtkSmartPointer<vtkMutableUndirectedGraph> NewGraph =
        vtkSmartPointer<vtkMutableUndirectedGraph>::New();

      //add 3 vertices
      NewGraph->AddVertex();
      NewGraph->AddVertex();
      NewGraph->AddVertex();

      output->ShallowCopy(NewGraph);

      return 1;
    }

    int vtkTestGraphAlgorithmSource::RequestDataObject(
      vtkInformation*,
      vtkInformationVector**,
      vtkInformationVector* )
    {

      vtkUndirectedGraph *output = 0;
      output = vtkUndirectedGraph::New();

      this->GetExecutive()->SetOutputData(0, output);
      output->Delete();

      return 1;
    }

    //----------------------------------------------------------------------------
    void vtkTestGraphAlgorithmSource::PrintSelf(ostream& os, vtkIndent indent)
    {
      this->Superclass::PrintSelf(os,indent);
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(vtkTestGraphAlgorithmSource)

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

    add_executable(vtkTestGraphAlgorithmSource MACOSX_BUNDLE vtkTestGraphAlgorithmSource.cxx)

    target_link_libraries(vtkTestGraphAlgorithmSource ${VTK_LIBRARIES})

### Download and Build vtkTestGraphAlgorithmSource

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

    cd vtkTestGraphAlgorithmSource/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:

    ./vtkTestGraphAlgorithmSource

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.