Warn if ga_model has no Shiny functions when used in Shiny - Error in unclass(x) : cannot unclass an external pointer

[MarkEdmondson1234]

Its obscure why Shiny doesn't work if it has no Shiny render/plot functions defined in the object:

decomp_ga <- ga_model_example("decomp_ga.gamr")
runApp('workshop-demo')

Listening on http://127.0.0.1:1221
2019-09-05 14:12:06> Downloaded [301] rows from a total of [301].
Rendering model output
Error in unclass(x) : cannot unclass an external pointer

Editing the object to include Shiny output functions fixes it:

shiny_model <- ga_model_edit(decomp_ga,
                             outputShiny = plotOutput,
                             renderShiny = renderPlot)