(* Copyright 2015 the Massachusetts Institute of Technology
Licensed under the Apache License, Version 2.0 (the "License"); you may not use
this file except in compliance with the License. You may obtain a copy of the
License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed
under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
CONDITIONS OF ANY KIND, either express or implied. See the License for the
specific language governing permissions and limitations under the License. *)
structure Configuration = struct
val main_page_name = "Main Page"
val wiki_title = "UrWiki demo"
end
type id = int
table commit : { Id : id,
Created : time,
Title : string,
Content : string }
PRIMARY KEY Id
sequence commit_id_next
datatype mode = View | Edit
val eq_mode =
mkEq (fn x y =>
case (x, y) of
(View, View) => True
| (Edit, Edit) => True
| _ => False)
fun only_in mode_source target_mode =
current_mode <- signal mode_source;
return (if current_mode = target_mode
then null
else Style.invisible)
fun current_revision title =
commits <- queryL1 (SELECT commit.Created, commit.Title, commit.Content
FROM commit
WHERE commit.Title = {[title]}
ORDER BY commit.Created ASC);
return (case commits of
Nil => {Title = title, Body = "Not found.", Modified = None}
| art :: _ => {Title = art.Title,
Body = show art.Content,
Modified = Some art.Created})
fun create_commit title text : transaction unit =
id <- nextval commit_id_next;
creation_time <- now;
dml (INSERT INTO commit (Id, Created, Title, Content)
VALUES ({[id]}, {[creation_time]}, {[title]}, {[text]}))
fun report_last_modified date =
This page was last modified at
{[timef "%l:%M:%S %P %Z on %A, %e %B %Y" date]}.
style content
style footer
style button_group
style top_bar
fun wiki requested_article_title =
(* Look up the article. *)
article <- current_revision requested_article_title;
(* Stuff article information into sources so we can live-update them as the
user edits. *)
article_body_source <- source article.Body;
article_modified_source <- source article.Modified;
(* Initially, we're in View mode, and we can switch to Edit mode on user
request. *)
page_mode <- source View;
return
{[if article.Title = Configuration.main_page_name
then Configuration.wiki_title
else article.Title ^ " – " ^ Configuration.wiki_title]}
(* Page headings *)