Ever PowerApp file should consist of the following:

Output Statement

Reference SCIRUN_DATA and SCIRUN_DATASET

Tcl Net Code

Assigment to mods Array

Auto Index to PowerAppBase.app

PowerApp Class Definition

Instantiate an App

Bind Commands

• Output Statement such as "Loading BioTensor (this may take a minute)..."
  

  puts "\nLoading BioTensor (this may take a minute)...\n"

• References SCIRUN_DATA and SCIRUN_DATASET and checks that these files exist in the net code.
  

  if {[file exists $DATADIR/$DATASET/demo-DWI.nrrd]} {
      set $m0-filename $DATADIR/$DATASET/demo-DWI.nrrd
  } else {
      set $m0-filename {}
  } 

• Tcl Net code which is just the normal tcl .net code.
  

  set m0 [addModuleAtPosition "Teem" "DataIO" "NrrdReader" 14 9]
  set m1 [addModuleAtPosition "Teem" "Unu" "UnuSlice" 603 169]
  set m2 [addModuleAtPosition "Teem" "Tend" "TendEpireg" 14 180]
  set m3 [addModuleAtPosition "Teem" "Tend" "TendEstim" 14 718]
  set m4 [addModuleAtPosition "Teem" "Tend" "TendBmat" 231 181]
  set m5 [addModuleAtPosition "Teem" "Unu" "UnuSlice" 992 516]
  .
  .
  .
  set c0 [addConnection $m119 0 $m40 0]
  set c1 [addConnection $m94 1 $m93 0]
  set c2 [addConnection $m130 1 $m120 0]
  set c3 [addConnection $m67 0 $m73 0]
  set c4 [addConnection $m67 0 $m33 0]
  .
  .
  .
  set $m0-notes {}
  set $m0-label {unknown}
  set $m0-type {Scalar}
  set $m0-axis {axis0}
  set $m0-add {0}
  

• Assignment of mods array
  

  global mods
  
  set mods(NrrdReader1) $m0
  set mods(DicomToNrrd1) $m97
  set mods(AnalyzeToNrrd1) $m96
  set mods(ChooseNrrd1) $m45
  set mods(NrrdInfo1) $m62
  
  ### Original Data Stuff
  set mods(UnuSlice1) $m1
  set mods(UnuProject1) $m57
  set mods(ShowField-Orig) $m8
  set mods(ChooseNrrd-ToProcess) $m113
  
  set mods(Viewer) $m44
  

• Auto index to PowerAppBase.app
  

  global SCIRUN_SRCDIR
  set auto_index(::PowerAppBase) \
     "source $SCIRUN_SRCDIR/Dataflow/GUI/PowerAppBase.tcl"
  

• PowerApp Class Definition making sure to inherit from PowerAppBase
  

  class BioTensorApp {
      inherit ::PowerAppBase
          
      constructor {} {
  .
  .
  .
  

• Instantiate an App and make sure to build it (usually done with the build_app method)
  

  BioTensorApp app
  
  app build_app
  

• Add Bind Commands must be after the creation of the app.
  

  bind all  {
      app save_session
  }
  
  bind all  {
      app load_session
  }
  
  bind all  {
      app exit_app
  }
  
  bind all  {
      global mods
      $mods(Viewer)-ViewWindow_0-c autoview
  }