[Haskell-beginners] confusion over yesod-forms-0.2.0

Michael Litchard michael at schmong.org
Thu Jun 23 04:24:14 CEST 2011

In this case the error was straightforwardly indicating the problem
and is now fixed. Derp.

On Wed, Jun 22, 2011 at 6:52 PM, Michael Litchard <michael at schmong.org> wrote:
> I installed the new yesod-forms-0.2.0
> I tried out the sample program hello-forms.hs. The new changes work
> just fine. No problems. I don't understand some of the notation, but
> that didn't stop me from using yesod-form prior to the changes. I
> copied the style of hello-form
> exactly, I think. But I got a compile error. I don't think the error
> indicates the actual problem, and I suspect I have left out something.
> Below is a link to hello-form, the code I am trying to compile and the
> error I get. I would appreciate any insight offered.
> hello-forms.hs
> http://hpaste.org/48177
> Handler/SSLvpn.hs
> http://hpaste.org/48178
> error
> Handler/SSLvpn.hs:43:14:
>    No instance for (RenderMessage Aframe FormMessage)
>      arising from a use of `selectField'
>    Possible fix:
>      add an instance declaration for (RenderMessage Aframe FormMessage)
>    In the first argument of `areq', namely `(selectField tests)'
>    In the second argument of `(<*>)', namely
>      `areq (selectField tests) "Pick a test" Nothing'
>    In the second argument of `($)', namely
>      `pure (,)
>     <*>
>       areq (multiSelectField servers) "Pick some servers" Nothing
>   <*>
>     areq (selectField tests) "Pick a test" Nothing'

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