Function with custom Options and modified Options for built-in Symbols

Question

I couldn't find a more descriptive title, but I guess an example will explain my problem.

I set up some customized Grid function including some additional functionalities which I control with custom Options. Additionally, I would like to change some of the standard Grid Options, e.g. always use Frame->All. Take the following working example:

Options[myGrid] = {Frame -> All, "Tooltip" -> False};
myGrid[content_, opts : OptionsPattern[]] :=
  Module[{con},
    If[OptionValue["Tooltip"],
      con = MapIndexed[Tooltip[#1, #2] &, content, {-1}],
      con = content
    ];
    Grid[con,
      Sequence @@ 
        FilterRules[{opts}~Join~Options[myGrid], Options[Grid]]
    ]
  ]

defining an example content:

mat = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};

We can test the behavior:

myGrid[mat]

The custom "Tooltip" flag works as intended. Now I want to pass an Option to Grid, that has not been explicitely set in the above Options[myGrid] declaration.This eventually makes it through to the Grid, but produces an error message.

myGrid[mat, Background -> Blue]

To get rid of the errors I embed the Options from Grid into my custom function:

Options[myGrid] = 
  Join[
    {Frame -> All, "Tooltip" -> False},
    Options[Grid]
  ];

Now, I can change the Grid Options without raising an error:

myGrid[mat, Background -> Green]

but the custom setting Frame->All gets lost.

myGrid[mat, Frame -> All]

Apparently, the default Frame->None setting for Grid overrules my custom setting. I banged my head against this problem for too long already, therefore my plea for your assistance.

Answer 1

OptionsPattern:

Therefore declare Options for both myGrid and Grid as valid:

Options[myGrid] = {Frame -> All, "Tooltip" -> False};

myGrid[content_, opts : OptionsPattern[{myGrid, Grid}]] := . . .

Then:

myGrid[mat, Background -> Blue]

Grid[mat, Background -> RGBColor[0, 0, 1], Frame -> All]

With no error message.

Answer 2

The problem in this particular case comes from the default setting of the Dividers option, which overrides the Frame option settings. This does not strike me as a right behavior, or at least these options are not as orthogonal as they should be. This appears to fix the problem:

Options[myGrid] = 
   Join[{Frame -> All, "Tooltip" -> False}, 
      DeleteCases[Options[Grid], Dividers -> _]];

On a general note, however, I would add all options you may ever want to pass to some functions inside your function, explicitly as valid options of your function. If you find this too bothersome, you can, for this particular function (myGrid), switch back to good old OptionQ pattern:

myGrid[content_, opts___?OptionQ] := ...

at the expense of the short "magical" version of OptionValue not working any more, so you will have to use OptionValue[myGrid,{opts},"Tooltip"]. I do this sometimes, in exactly this sort of situations.