Using MonadRouted

[billrockx]

How to use routeApp to add routing to my webpage.

testApp :: MonadWidget t m => m ()
testApp = do
  routeApp "app" $ do
    withPathSegment go
  pure ()
  where
    go ::  (MonadWidget t m, MonadRouted t m) => Dynamic t (Maybe PathSegment) -> m ()
    go dPathSeg = do
      (dyn . ffor dPathSeg) $ \ps -> do
        case maybe "a" id ps of
          "a" -> do
            evt <- button "switch to View B"
            redirectInternal $ ("b" <$ evt)
            text "View A"
          "b" -> do
            evt <- button "switch to View A"
            redirectInternal $ ("a" <$ evt)
            text "View B"
      pure ()

I get this error while running the code:

Could not deduce (NotReady t (RouteT t m))
        arising from a use of ‘go’
      from the context: MonadWidget t m
        bound by the type signature for:
                   testApp :: MonadWidget t m => m ()

[mightybyte]

Ahh, it looks like we need to provide an instance for the new NotReady type class in reflex (https://github.com/reflex-frp/reflex/blob/develop/src/Reflex/NotReady/Class.hs).

However, Obsidian has a new router system they've been working on as a part of Obelisk. The source is here:

https://github.com/obsidiansystems/obelisk/blob/master/lib/route/src/Obelisk/Route.hs

And here is an example of how reflex-frp.org uses it:

https://github.com/reflex-frp/reflex-frp.org/blob/master/common/src/Common/Route.hs

MonadRouted was thrown together pretty quickly to get something usable. The new obelisk routing infrastructure is much more carefully thought out, so I would recommend switching to that.