Mercurial > urweb
view demo/tree.ur @ 688:829887ca47a6
Detect serialization failures
author | Adam Chlipala <adamc@hcoop.net> |
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date | Thu, 02 Apr 2009 13:31:13 -0400 |
parents | 20fab0e96217 |
children | 1a317a707d71 |
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sequence s table t : { Id : int, Parent : option int, Nam : string } open TreeFun.Make(struct val tab = t end) fun row r = <xml> #{[r.Id]}: {[r.Nam]} <a link={del r.Id}>[Delete]</a> <form> Add child: <textbox{#Nam}/> <submit action={add (Some r.Id)}/> </form> </xml> and main () = xml <- tree row None; return <xml><body> {xml} <form> Add a top-level node: <textbox{#Nam}/> <submit action={add None}/> </form> </body></xml> and add parent r = id <- nextval s; dml (INSERT INTO t (Id, Parent, Nam) VALUES ({[id]}, {[parent]}, {[r.Nam]})); main () and del id = dml (DELETE FROM t WHERE Id = {[id]}); main ()