Mercurial > urweb
diff tests/rpcDE.ur @ 638:3ee6bb48f6e8
RPC returning an enumeration
| author | Adam Chlipala <adamc@hcoop.net> |
|---|---|
| date | Sun, 08 Mar 2009 12:37:42 -0400 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/tests/rpcDE.ur Sun Mar 08 12:37:42 2009 -0400 @@ -0,0 +1,30 @@ +datatype result = Neg | Zero | Pos + +table t : {A : int} + +fun main () : transaction page = + let + fun check () = + r <- oneRow (SELECT SUM(t.A) AS X FROM t); + return (if r.X < 0 then + Neg + else if r.X = 0 then + Zero + else + Pos) + + fun show r = + case r of + Neg => <xml>-</xml> + | Zero => <xml>0</xml> + | Pos => <xml>+</xml> + in + s <- source Zero; + return <xml><body> + <button value="Get It On!" + onclick={r <- check (); + set s r}/><br/> + <br/> + Current: <dyn signal={r <- signal s; return (show r)}/> + </body></xml> + end