Merge pull request #547 from pfitaxel/dont-prefix-absolute-urls

* Don't prefix URLs starting with `https?://` at `learn-ocaml build` time
Related: #535 and static deployment

* Move CSS code as a small cleanup
Related: #540

src/main/learnocaml_main.ml

@@ -257,10 +257,18 @@ end
 open Args
 
 let process_html_file orig_file dest_file base_url no_secret =
+  let add_prefix_unless_http prefix url =
+    let https = "https://" and http = "http://" in
+    let starts_with proto =
+      String.(sub url 0 (min (length proto) (length url))) = proto in
+    if starts_with https || starts_with http then url
+    else prefix ^ url in
   let transform_tag e tag attrs attr =
     let attr_pair = ("", attr) in
     match List.assoc_opt attr_pair attrs with
-    | Some url -> `Start_element ((e, tag), (attr_pair, base_url ^ url) :: (List.remove_assoc attr_pair attrs))
+    | Some url -> `Start_element ((e, tag),
+                                  (attr_pair, add_prefix_unless_http base_url url)
+                                  :: (List.remove_assoc attr_pair attrs))
     | None -> `Start_element ((e, tag), attrs) in
   Lwt_io.open_file ~mode:Lwt_io.Input orig_file >>= fun ofile ->
   Lwt_io.open_file ~mode:Lwt_io.Output dest_file >>= fun wfile ->

static/css/learnocaml_common.css

@@ -15,21 +15,6 @@ code, pre, textarea {
   line-height: 18px;
 }
 
-div.anon-id span.student::before, 
-div.anon-id li.student::before {
-  content: attr(data-anon);
-}
-
-div.token-id span.student::before,
-div.token-id li.student::before {
-  content: attr(data-token);
-}
-
-div.nickname-id span.student::before,
-div.nickname-id li.student::before {
-  content: attr(data-nickname);
-}
-
 /* -------------------- fix browser's CSSs ------------------------ */
 button > img {
   vertical-align: -10%;

static/css/learnocaml_partition_view.css

@@ -12,3 +12,15 @@ span.student {
   background-color: lightyellow;
   cursor: pointer;
 }
+
+div.anon-id span.student::before, div.anon-id li.student::before {
+  content: attr(data-anon);
+}
+
+div.token-id span.student::before, div.token-id li.student::before {
+  content: attr(data-token);
+}
+
+div.nickname-id span.student::before, div.nickname-id li.student::before {
+  content: attr(data-nickname);
+}