Mercurial > urweb
diff demo/batch.ur @ 649:96ebc6bdb5a0
Batch example
| author | Adam Chlipala <adamc@hcoop.net> |
|---|---|
| date | Tue, 10 Mar 2009 15:17:23 -0400 |
| parents | |
| children | 1a317a707d71 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/demo/batch.ur Tue Mar 10 15:17:23 2009 -0400 @@ -0,0 +1,80 @@ +datatype list t = Nil | Cons of t * list t + +table t : {Id : int, A : string} + +fun allRows () = + query (SELECT * FROM t) + (fn r acc => return (Cons ((r.T.Id, r.T.A), acc))) + Nil + +fun doBatch ls = + case ls of + Nil => return () + | Cons ((id, a), ls') => + dml (INSERT INTO t (Id, A) VALUES ({[id]}, {[a]})); + doBatch ls' + +fun del id = + dml (DELETE FROM t WHERE t.Id = {[id]}) + +fun show withDel lss = + let + fun show' ls = + case ls of + Nil => <xml/> + | Cons ((id, a), ls) => <xml> + <tr><td>{[id]}</td> <td>{[a]}</td> {if withDel then + <xml><td><button value="Delete" onclick={del id}/></td></xml> + else + <xml/>} </tr> + {show' ls} + </xml> + in + <xml><dyn signal={ls <- signal lss; return <xml><table> + <tr> <th>Id</th> <th>A</th> </tr> + {show' ls} + </table></xml>}/></xml> + end + +fun main () = + lss <- source Nil; + batched <- source Nil; + + id <- source ""; + a <- source ""; + + let + fun add () = + id <- get id; + a <- get a; + ls <- get batched; + + set batched (Cons ((readError id, a), ls)) + + fun exec () = + ls <- get batched; + + doBatch ls; + set batched Nil + in + return <xml><body> + <h2>Rows</h2> + + {show True lss} + + <button value="Update" onclick={ls <- allRows (); set lss ls}/><br/> + <br/> + + <h2>Batch new rows to add</h2> + + <table> + <tr> <th>Id:</th> <td><ctextbox source={id}/></td> </tr> + <tr> <th>A:</th> <td><ctextbox source={a}/></td> </tr> + <tr> <th/> <td><button value="Batch it" onclick={add ()}/></td> </tr> + </table> + + <h2>Already batched:</h2> + {show False batched} + <button value="Execute" onclick={exec ()}/> + </body></xml> + end