Closes JuliaComputing#26 - Only wrap with invokelatest on the first use

Minor adjustment to return the invokelatest wrapped filter on the first use. The world will be ready for the actual function on subsequent uses.

src/TableView.jl

@@ -278,9 +278,9 @@ function _filterfn(filtermodel)
  return _filterfns[code]
  end
 
- println("For filterModel: $filtermodel")
- println("Built code: $code")
- return _filterfns[code] = eval(Meta.parse(code))
+ fltr = _filterfns[code] = eval(Meta.parse(code))
+ # On the first call, we need to wrap the function to invokelatest
+ return (row) -> Base.invokelatest(fltr, row)
 end
 
 function _showtable_async!(w, names, types, rows, coldefs, tablelength, dark, id, onCellValueChanged)
@@ -291,10 +291,7 @@ function _showtable_async!(w, names, types, rows, coldefs, tablelength, dark, id
  on(rowparams) do x
  filtermodel = x["filterModel"]
  if length(filtermodel) > 0
- fltr = _filterfn(filtermodel)
- data = Base.Iterators.filter(rows) do row
- Base.invokelatest(fltr, row)
- end
+ data = Base.Iterators.filter(_filterfn(filtermodel), rows)
  else
  data = rows
  end