~ assets

src/assets.ml

@@ -9,7 +9,22 @@
      https://docs.taler.net/manpages/taler-exchange.conf.5.html
      https://docs.taler.net/design-documents/003-tos-rendering.html *)
 
-type kind = Terms | Privacy
+(* todo: maybe move this type to config.ml *)
+type t = Terms | Privacy
+
+let etag = function
+  | Terms -> Config.terms_etag
+  | Privacy -> Config.privacy_etag
+
+let legal_version = function
+  | Terms -> Config.terms_legal_version
+  | Privacy -> Config.privacy_legal_version
+
+let base_dir = function
+  | Terms -> Config.terms_dir
+  | Privacy -> Config.privacy_dir
+
+let path ~lang ~ext t = Fpath.((base_dir t / lang / etag t) + ext)
 
 (* TODO
    better use of Fmt to have error prefix or smthing
@@ -22,13 +37,9 @@ let supported_lang_arr, supported_ext_arr =
     | Error (`Msg e) -> Fmt.failwith "%s" e
     | Ok x -> x
   in
-  let aux kind =
-    let base_dir =
-      match kind with
-      | Terms -> Config.terms_dir
-      | Privacy -> Config.privacy_dir
-    in
-    let path_l = path_l |> List.filter_map (Fpath.rem_prefix base_dir) in
+  let aux t =
+    let prefix = base_dir t in
+    let path_l = path_l |> List.filter_map (Fpath.rem_prefix prefix) in
     let ext_l =
       path_l |> List.map Fpath.get_ext |> List.sort_uniq String.compare
     in
@@ -87,14 +98,8 @@ let supported_lang_arr, supported_ext_arr =
 let is_supported_lang lang = Array.mem lang supported_lang_arr
 let is_supported_ext ext = Array.mem ext supported_ext_arr
 
-let get_content ~lang ~ext kind =
-  let path =
-    let open Config in
-    match kind with
-    | Terms -> Fpath.((terms_dir / lang / terms_etag) + ext)
-    | Privacy -> Fpath.((privacy_dir / lang / privacy_etag) + ext)
-  in
-  let path_str = Fpath.to_string path in
-  match Assets_crunch.read path_str with
-  | None -> Fmt.error "static file not found: `%s`" path_str
+let get_content ~lang ~ext t =
+  let path = Fpath.to_string (path ~lang ~ext t) in
+  match Assets_crunch.read path with
+  | None -> Fmt.error "static file not found: `%s`" path
   | Some data -> Ok data

src/config.ml

@@ -11,3 +11,5 @@ let privacy_dir = Fpath.(v "privacy")
 (* ETAG is used as filename *)
 let terms_etag = "0"
 let privacy_etag = "0"
+let terms_legal_version = "1"
+let privacy_legal_version = "1"

src/mte.ml

@@ -57,34 +57,31 @@ module Static = struct
   (* - try to find a response with an acceptable mime-type,
      - then pick the version in the most preferred language of the user,
      - and finally apply compression if that is allowed by the client
+     - set ETAG header
 
      TODO:
-       - set an ETAG,
        - subsequent requests of the client should provide the tag in an "If-None-Match" header
-         to detect if the terms of service have changed.
-       - If not, a "304 Not Modified" response will be returned.
-         Note that the “304 Not Modified” will also be returned if the client changed
-         the "Accept-Language" or "Accept-Encoding" header.
-       - The ETAG is encoded in Crockford base-32.
-       - A "Taler-Terms-Version" header is generated to indicate the legal version of the terms.
+         to detect if the terms of service have changed
+       - If it did not change, a "304 Not Modified" response will be returned
+       - The ETAG is encoded in Crockford base-32
+       - A "Taler-Terms-Version" header is generated to indicate the legal version of the terms
        - When returning a full response (not a “304 Not Modified”), the server
          should also include a “Avail-Languages” header which includes a
          comma-separated list of the languages in which the terms of service are available in
 
   *)
 
-  (* accept_ext_l and accept_lang_l are assumed to be sorted by preference *)
   let select_file headers kind =
     let open Syntax in
-    let accept_ext_l = Header_util.parse_accept_header headers in
-    let accept_lang_l = Header_util.parse_accept_language_header headers in
     let* ext =
-      accept_ext_l
+      headers
+      |> Header_util.parse_accept_header
       |> List.find_opt Assets.is_supported_ext
       |> Option.to_result ~none:"no acceptable mimetype"
     in
     let* lang =
-      accept_lang_l
+      headers
+      |> Header_util.parse_accept_language_header
       |> List.find_opt Assets.is_supported_lang
       |> Option.to_result ~none:"no acceptable language"
     in
@@ -96,6 +93,7 @@ module Static = struct
   let static kind req _server _env =
     let open Vif.Response.Syntax in
     let headers = Vif.Request.headers req in
+    let _if_none_match = Vif.Headers.get headers "if-none-match" in
     let data =
       match select_file headers kind with
       | Error e -> Fmt.failwith "%s" e
@@ -103,8 +101,9 @@ module Static = struct
     in
     let compression = Header_util.select_encoding headers in
     let* () = Vif.Response.with_string ?compression req data in
-    let field = "content-type" in
-    let* () = Vif.Response.add ~field "html; charset=utf-8" in
+    let* () = Vif.Response.add ~field:"ETAG" (Assets.etag kind) in
+    (* TODO content-type *)
+    let* () = Vif.Response.add ~field:"content-type" "html; charset=utf-8" in
     Vif.Response.respond `OK
 
   let terms = static Assets.Terms

src/util.ml

@@ -13,7 +13,7 @@ let is_valid_filename, media_to_extension =
     ; (("image", "gif"), "gif")
     ]
   in
-  (* <> than the actual set of "supported" extension (depends on config files) *)
+  (* <> than the actual set of "supported" extension (which depends on config files) *)
   let all_known_extensions = mimetype_ext_assoc |> List.split |> snd in
   let is_valid_filename path = Fpath.mem_ext all_known_extensions path in
   let media_to_extension = function