As of version 1.3.15.2 the focus property no longer works for file widgets:
local dlg = Dialog { title = "File Focus" }
dlg:file {
id = "myFileWidget",
label = "File:",
filetypes = { "png" },
basepath = app.fs.userDocsPath,
focus = true,
}
dlg:show { wait = false }
I mentioned it in another thread, but the file widget UX goes a long way towards custom open file routines that can be done in a few key presses.