Allow Select to accept non-string option values

I think it would be useful to have the Select widget values to be any object: for example it maybe useful for the select.value to point to a function.

Consider this (hypothetical) instance of a Select widget:

select = Select(title="Options:",
                value=do_1,
                options=[(do_1,"option_1"), (do_2,"option_2"), (do_3,"option_3"), (do_4,"option_4")])

where do_n is a previously defined function. I have chosen to have (value, label) pairs as options so a user could select an option and the relevant function could be accessed by accessing the value attribute of my widget (i.e., select.value). Currently this isn’t supported and I will have to store my functions in a dictionary with suitable keys selected by the widget.

There is a related issue (bug?) that the value attribute fed to initiate the Select widget can only be a String. It would be nice to to support this kind of functionality:

select = Select(title="Options:",
                value=1,
                options=[(1,"option_1"), (2,"option_2"), (3,"option_3"), (4,"option_4")])

Currently this does not work but in some instances is required (i.e., when using the select widget to access a list and a default value is required).

[bryevdv]

Do you mean raise a bug report?

@FChmiel no I think I misinterpreted this:

There is a related issue (bug?) that the value attribute fed to initiate the Select widget can only be a String. It would be nice to to support this kind of functionality:

to mean there is a related GH issue here somewhere.

This issue is great for figuring out how to expand supported values in Select

[jbednar]

The Param library works like this, with the value of a Selector being an actual item (integer, function, etc.) and the Panel library being used to make a corresponding Bokeh widget. See e.g. the select_fn parameter in the Panel Param docs. This doesn’t change whether Bokeh itself could or should act like this, but I think it does let you do the sort of thing you’re asking for, and it might be an approach to consider.