Move selection to next Output and export to CDF

Question

In my quest to a custom "Save as HTML" (please see context here) I am now able to iterate through the notebook, grab Input cells decorated with a CellTag that, by convention, is going to be a file name of a CDF file. The CDF needs to come from the corresponding Output cell if that Input cell. For simplicity, I am assuming it is the next one. So, I am trying to SelectionMove[nb, Next, Cell] (* 1 *) but my debugging in (* 2 *) doesn't work and the actual export in (* 3 *) fails. See below

PaletteNotebook[
 Button[Style["Blog it", 12, FontFamily -> "Times"],
  Block[{
    nb = InputNotebook[],
    out = NotebookCreate[],
    fpath = NotebookDirectory[InputNotebook[]],
    generateCDF,
    generateCDFs,
    exportHTML
    },
   generateCDF[nb_, name_] := Module[{sel},
     sel = SelectionMove[nb, Next, Cell]; (* 1 *)

     Message[generateCDF::info, name];
     NotebookWrite[out, CurrentValue[{sel, Cell}]]; (* 2 *)

     Export[
      FileNameJoin[{fpath, name}],
      CurrentValue[sel, Cell],
      "CDF"]; (* 3 *)

     SelectionMove[nb, "Input", Next, CellStyle]
     ];
   generateCDF::info = "Generating CDF `1`";
   generateCDFs[nb_] := Module[{sel, curID},
     SelectionMove[nb, Before, Notebook];
     sel = NotebookFind[nb, "Input", Next, CellStyle];
     While[ MatchQ[sel, _NotebookSelection],
      curID = CurrentValue[sel, CellID];
      sel = Switch[CurrentValue[sel, CellTags],
        _String, generateCDF[nb, CurrentValue[sel, CellTags]],
        _, NotebookFind[nb, "Input", Next, CellStyle]
        ];
      ];
     ];
   exportHTML[nb_] := False; (* yet to be done, ignore for now *)

   generateCDFs[nb];
   exportHTML[nb];
   ],
  Appearance -> "Palette"]
 ]

The Message is printing properly in the message window.

Answer 1

Have you any indication that CurrentValue[{sel,Cell}] should work? I didn't find any such statement in the documentation so I think in this case you need to use NotebookRead instead of CurrentValue. Note that even CurrentValue[nb,"SelectionData"] won't get you the selected cell but rather seems to be addressing dynamic selection with the mouse. Another thing you need to change is that Export[...,"CDF"] doesn't accept Cell expressions but wants Notebook expressions. Alltoghether this works for me:

PaletteNotebook[
 Button[
  Style["Blog it", 12, FontFamily -> "Times"],
  Module[{
    nb = InputNotebook[],
    fpath = NotebookDirectory[InputNotebook[]],
    out = NotebookCreate[],
    generateCDF, generateCDFs, exportHTML
    },
   generateCDF[nb_, name_] := Module[{sel},
     sel = SelectionMove[nb, Next, Cell];(*1*)
     Message[generateCDF::info, name];
     NotebookWrite[out, NotebookRead[nb]];(*2*)
     Export[FileNameJoin[{fpath, name}], Notebook[{NotebookRead[nb]}],
       "CDF"];(*3*)
     SelectionMove[nb, "Input", Next, CellStyle]
     ];
   generateCDF::info = "Generating CDF `1`";
   generateCDFs[nb_] := Module[{sel, curID},
     SelectionMove[nb, Before, Notebook];
     sel = NotebookFind[nb, "Input", Next, CellStyle];
     While[MatchQ[sel, _NotebookSelection],
      curID = CurrentValue[sel, CellID];
      sel = Switch[CurrentValue[sel, CellTags],
        _String, generateCDF[nb, CurrentValue[sel, CellTags]],
        _, NotebookFind[nb, "Input", Next, CellStyle]
        ];
      ];
     ];
   generateCDFs[nb];
   ],
  Appearance -> "Palette"]
 ]

I have also replaced Block with Module as I think it is more appropriate here and I've seen some subtleties with Block in dynamic code, as is explained here.