From: rich <rich>
Date: Fri, 24 Sep 2004 10:44:55 +0000 (+0000)
Subject: Highlighting of search terms.
X-Git-Url: http://git.annexia.org/?a=commitdiff_plain;h=3f36aa55afe2e7ddf3054d019cd35750071f2163;p=cocanwiki.git

Highlighting of search terms.
Updated MANIFEST.
Bumped release.
---

diff --git a/MANIFEST b/MANIFEST
index 1ff9732..0645dce 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -50,6 +50,7 @@ scripts/admin/edit_hostnames_form.ml
 scripts/admin/host.ml
 scripts/cgi_expires.ml
 scripts/cocanwiki.ml
+scripts/cocanwiki_cgi_args.ml
 scripts/cocanwiki_date.ml
 scripts/cocanwiki_diff.ml
 scripts/cocanwiki_emailnotify.ml
diff --git a/debian/changelog b/debian/changelog
index 419ecc0..349ca03 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,4 +1,4 @@
-cocanwiki (1.1.1-2) unstable; urgency=low
+cocanwiki (1.1.1-3) unstable; urgency=low
 
   * Initial Release.
 
diff --git a/html/_css/standard.css b/html/_css/standard.css
index e3efb00..2327c0b 100644
--- a/html/_css/standard.css
+++ b/html/_css/standard.css
@@ -1,5 +1,5 @@
 /* Stylesheet for COCANWIKI.
- * $Id: standard.css,v 1.4 2004/09/17 12:34:33 rich Exp $
+ * $Id: standard.css,v 1.5 2004/09/24 10:44:55 rich Exp $
  */
 
 body {
@@ -236,3 +236,9 @@ table.left_table td {
 table.left_table td.number {
   text-align: right;
 }
+
+/* Highlighting search terms. */
+span.search_term {
+  background-color: #ff0;
+  border: 1px solid #eeb;
+}
\ No newline at end of file
diff --git a/scripts/Makefile b/scripts/Makefile
index f5ddf10..ff8e09b 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -1,5 +1,5 @@
 # Makefile for COCANWIKI.
-# $Id: Makefile,v 1.21 2004/09/23 15:16:21 rich Exp $
+# $Id: Makefile,v 1.22 2004/09/24 10:44:55 rich Exp $
 
 include ../Makefile.config
 
@@ -8,6 +8,7 @@ OCAMLCFLAGS := -w s -I +apache -I +pcre -I +dbi -I +extlib
 CPP := cpp
 
 LIB_OBJS := \
+	cocanwiki_cgi_args.cmo \
 	cocanwiki_date.cmo \
 	cocanwiki_version.cmo \
 	cocanwiki_files.cmo \
diff --git a/scripts/cocanwiki_cgi_args.ml b/scripts/cocanwiki_cgi_args.ml
new file mode 100644
index 0000000..c019c0d
--- /dev/null
+++ b/scripts/cocanwiki_cgi_args.ml
@@ -0,0 +1,45 @@
+(* COCANWIKI - a wiki written in Objective CAML.
+ * Written by Richard W.M. Jones <rich@merjis.com>.
+ * Copyright (C) 2004 Merjis Ltd.
+ * $Id: cocanwiki_cgi_args.ml,v 1.1 2004/09/24 10:44:55 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
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * This badly needs to become a standard part of the Cgi library.
+ *)
+
+let split1_re = Pcre.regexp "\\?"
+let split2_re = Pcre.regexp "&"
+let split3_re = Pcre.regexp "="
+
+let parse full_url =
+  let url, qs = match Pcre.split ~rex:split1_re ~max:2 full_url with
+    | [url] | [url;""] -> url, None
+    | [url;qs] -> url, Some qs
+    | _ -> assert false in
+  let args = match qs with
+      None -> []
+    | Some qs ->
+	let args = Pcre.split ~rex:split2_re qs in
+	let f arg =
+	  match Pcre.split ~rex:split3_re ~max:2 arg with
+	    | [] -> ("", "")
+	    | [key] -> (key, "")
+	    | [key;value] -> (key, value)
+	    | _ -> assert false
+	in
+	List.map f args in
+  url, qs, args
diff --git a/scripts/page.ml b/scripts/page.ml
index bd4d05a..1ea4acd 100644
--- a/scripts/page.ml
+++ b/scripts/page.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: page.ml,v 1.19 2004/09/23 15:16:21 rich Exp $
+ * $Id: page.ml,v 1.20 2004/09/24 10:44:55 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
@@ -39,6 +39,18 @@ type fp_status = FPOK of int * string * string * Dbi.datetime * bool
 	       | FPRedirect of string
 	       | FPNotFound
 
+(* Referer strings which help us decide if the user came from
+ * a search engine and highlight terms in the page appropriately.
+ *)
+let search_engines = [
+  Pcre.regexp "^http://.*google\\.", [ "q"; "as_q"; "as_epq"; "as_oq" ];
+  Pcre.regexp "^http://.*yahoo\\.", [ "p" ];
+  Pcre.regexp "^http://.*msn\\.", [ "q"; "MT" ]
+]
+let split_words = Pcre.regexp "\\W+"
+
+let xhtml_re = Pcre.regexp "<.*?>|[^<>]+"
+
 let run r (q : cgi) (dbh : Dbi.connection) hostid {edit_anon=edit_anon} user =
   let template_page = get_template dbh hostid "page.html" in
   let template_404  = get_template dbh hostid "page_404.html" in
@@ -67,6 +79,71 @@ let run r (q : cgi) (dbh : Dbi.connection) hostid {edit_anon=edit_anon} user =
   (* Do we have a stats page set up? *)
   let has_stats = server_settings_stats_page dbh <> None in
 
+  (* Given the referer string, return the list of search terms.  If none
+   * can be found, then throws Not_found.
+   *)
+  let search_terms_from_referer referer =
+    let _, argnames =
+      List.find (fun (rex, _) -> Pcre.pmatch ~rex referer) search_engines in
+    let _, _, args = Cocanwiki_cgi_args.parse referer in
+    let argname =
+      List.find (fun argname -> List.mem_assoc argname args) argnames in
+    let search_string = List.assoc argname args in
+    Pcre.split ~rex:split_words search_string
+  in
+
+  (* Given a full page of XHTML, highlight search terms found in the
+   * <body> part of the page.
+   *)
+  let highlight_search_terms xhtml search_terms span_class =
+    (* Split the original XHTML into strings and tags.  For example if
+     * the original string is: "This is some <b>bold</b> text.<br/>", then
+     * after this step we will have the following list:
+     * [ "This is some "; "<b>"; "bold"; "</b>"; " text."; "<br/>" ]
+     *)
+    let xhtml = Pcre.extract_all ~rex:xhtml_re xhtml in
+    let xhtml = Array.to_list xhtml in
+    let xhtml = List.map (fun matches -> matches.(0)) xhtml in
+
+    (* Find the <body> ... </body> tags.  We only want to apply
+     * highlighting to tags within this area.
+     *)
+    let rec list_split f acc = function
+      | [] -> List.rev acc, []
+      | ((x :: _) as xs) when f x -> List.rev acc, xs
+      | x :: xs ->
+	  let acc = x :: acc in
+	  list_split f acc xs
+    in
+    let head, body =
+      list_split (fun str -> String.starts_with str "<body") [] xhtml in
+    let body, tail =
+      list_split ((=) "</body>") [] body in
+    (* NB: Hopefully, xhtml = head @ body @ tail. *)
+
+    (* The search terms are a list of simple words.  Turn into a big
+     * regular expression, because we want to substitute for each.  We
+     * end up with a regexp like '(word1|word2|word3)'.
+     *)
+    let rex =
+      Pcre.regexp ~flags:[`CASELESS]
+        ("(" ^ String.concat "|" search_terms ^ ")") in
+
+    (* Do the substitution, but only on text, not elements! *)
+    let body =
+      let subst text =
+	"<span class=\"" ^ span_class ^ "\">" ^ text ^ "</span>"
+      in
+      List.map (fun str ->
+                  if String.length str > 0 && str.[0] != '<' then
+                    Pcre.substitute ~rex ~subst str
+                  else
+                    str) body in
+
+    (* Join the XHTML fragments back together again. *)
+    String.concat "" (List.concat [ head ; body ; tail ])
+  in
+
   (* This code generates ordinary pages. *)
   let make_page title description pageid last_modified_date has_page_css
       version page page' =
@@ -150,7 +227,24 @@ let run r (q : cgi) (dbh : Dbi.connection) hostid {edit_anon=edit_anon} user =
 	   t#conditional "user_logged_in" true;
 	   t#set "username" username);
 
-    q#template t
+    (* If we are coming from a search engine then we want to highlight
+     * search terms throughout the whole page ...
+     *)
+    try
+      let referer = Table.get (Request.headers_in r) "Referer" in
+      let search_terms = search_terms_from_referer referer in
+
+      (* Highlight the search terms. *)
+      let xhtml = t#to_string in
+      let xhtml = highlight_search_terms xhtml search_terms "search_term" in
+
+      (* Deliver the page. *)
+      q#header ();
+      print_string r xhtml
+    with
+	Not_found ->
+	  (* No referer / no search terms / not a search engine referer. *)
+	  q#template t
   in
 
   (* This code generates 404 pages. *)