New, cleaner stylesheet:

[cocanwiki.git] / scripts / cocanwiki_links.ml

diff --git a/scripts/cocanwiki_links.ml b/scripts/cocanwiki_links.ml
index 101ca64..cd3b13f 100644 (file)
--- a/scripts/cocanwiki_links.ml
+++ b/scripts/cocanwiki_links.ml
@@ -1,7 +1,7 @@
 (* COCANWIKI - a wiki written in Objective CAML.
  * Written by Richard W.M. Jones <rich@merjis.com>.
  * Copyright (C) 2004 Merjis Ltd.
- * $Id: cocanwiki_links.ml,v 1.3 2004/10/07 12:22:11 rich Exp $
+ * $Id: cocanwiki_links.ml,v 1.5 2004/10/10 16:14:43 rich Exp $
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -22,6 +22,8 @@
 open ExtString
 open ExtList
 
+open Cocanwiki
+
 let split_tags_re = Pcre.regexp ~flags:[`DOTALL] "<.*?>|[^<]+"
 let internal_re = Pcre.regexp "class=\"internal\""
 let newpage_re = Pcre.regexp "class=\"newpage\""
@@ -122,3 +124,51 @@ let update_links_for_page dbh hostid page =
        let links = get_links_from_section dbh hostid content in
        List.iter (insert_link dbh hostid page) links
        | _ -> assert false)
+
+(* Because of redirects, getting the list of pages which link to this
+ * page isn't a matter of just doing 'select from_url from links ...'.
+ * We also look at pages which redirect to this URL (for redirections
+ * of degrees 1 through 4 = max_redirect).
+ *)
+let what_links_here (dbh : Dbi.connection) hostid page =
+  (* Build up the complete list of URLs which redirect to the target
+   * page, within max_redirect redirections.  This is sort of like
+   * Prim's algorithm.
+   *)
+  let urls = ref [page] in
+  let found = ref true in
+  let i = ref 1 in
+  while !found && !i <= max_redirect do
+    let qs = Dbi.placeholders (List.length !urls) in
+    let sql =
+      "select url from pages
+        where hostid = ?
+          and url is not null and redirect is not null
+          and url not in " ^ qs ^ " and redirect in " ^ qs in
+    let sth = dbh#prepare_cached sql in
+    let args = List.map (fun s -> `String s) !urls in
+    sth#execute (`Int hostid :: (args @ args));
+    let new_urls = sth#map (function [`String s] -> s | _ -> assert false) in
+    urls := !urls @ new_urls;
+    found := new_urls <> [];
+    incr i
+  done;
+
+  let urls = !urls in
+
+  (* Now find any pages which link to one of these target pages.  For
+   * convenience we also select out the titles.
+   *)
+  let qs = Dbi.placeholders (List.length urls) in
+  let sth =
+    dbh#prepare_cached
+      ("select li.from_url, p.title, li.from_url = 'index'
+          from links li, pages p
+         where li.hostid = ? and li.to_url in " ^ qs ^ "
+           and li.hostid = p.hostid and li.from_url = p.url
+         order by 3 desc, 2, 1") in
+  sth#execute (`Int hostid :: (List.map (fun s -> `String s) urls));
+
+  sth#map (function
+            | [`String url; `String title; _] -> url, title
+            | _ -> assert false)