Import data from excel and store it permanently in notebook

Question

I am trying to write the code for doing the following:

1. by clicking a button, import specific data from an Excel file which I select through a dialog window;
2. input a name for the imported data set through an input field;
3. store the imported data permanently under the given name (for example a variable with that name), so that I don't have to import it again next time I open Mathematica;
4. repeat 1. - 3. , etc.

The idea is to be able to have several data sets imported from several Excel files, assign specific names to them and store all of them inside the notebook permanently.

Could someone please guide me to achieve this?

Answer 1

My approach to this task would be to create new Input Cells within the notebook, that have the same structure as newly typed in symbol definition.

createNewSymbol[] :=
 Module[{importFileName = SystemDialogInput["FileOpen", ".txt"]},
  With[{importedData = If[StringQ@importFileName, Import[importFileName, "Table"]],
        symName = If[StringQ@importFileName, Input["Enter Symbol Name"]]},
   If[ListQ@importedData && ! MatchQ[symName, $Canceled], 
    CellPrint@ExpressionCell[Defer[symName = importedData;], "Input", 
      InitializationCell -> True]];
   If[StringQ@importFileName, createNewSymbol[]];
   ]]

Button["Create New Symbols with Imported Data", createNewSymbol[], Method -> "Queued"]

I used the following .txt files for testing

Export["aTest.txt", RandomInteger[10, 100]];
Export["bTest.txt", RandomReal[1, 100]];
Export["cTest.txt", RandomPrime[100, 100]];

therefore you will have to adapt my code for your Excel files.

Answer 2

it is not etirely clear for what you need that, but I think the best way to store data within a Notebook so that it is available in the next session is the TaggingRules option. This is how you could store data for a there:

 CurrentValue[EvaluationNotebook[],{TaggingRules,"dataset-name"}] = data;

And this is how you can read it:

 data = CurrentValue[EvaluationNotebook[],{TaggingRules,"dataset-name"}];

for most applications it will be fast enough to just use that. To make it more convenient you could define e.g.:

saveDataset[name_String,data_] := saveDataset[name_String,data_] := (
  CurrentValue[EvaluationNotebook[],{TaggingRules,name}] = data
);
getDataset[name_String] := (
  CurrentValue[EvaluationNotebook[],{TaggingRules,name}]
);

if the access via frontend would be too slow you could cache the data in the kernel:

getDataset[name_String] := getDataset[name] = (
  CurrentValue[EvaluationNotebook[],{TaggingRules,name}]
);

but that would mean you should also redefine when the data changes, so you'll also need to update the cached value if a dataset ever should change:

saveDataset[name_String,data_] := (
  getDataset[name] = 
    CurrentValue[EvaluationNotebook[],{TaggingRules,name}] = data;
);