refactor some code

src/discuss.ml

@@ -1,4 +1,5 @@
 open Db
+open Syntax
 
 (** Creating the table of all messages.
 
@@ -57,87 +58,62 @@ let find_messages k1 k2 =
   Ok comrades
 
 (** display the list of discussions *)
-let render request =
-  match Dream.session "user_id" request with
-  | None ->
-    let redirect_url =
-      Format.sprintf "/login=?redirect=%s" (Dream.to_percent_encoded "/discuss")
-    in
-    Dream.respond ~status:`See_Other ~headers:[ ("Location", redirect_url) ] ""
-  | Some user_id -> (
-    match find_comrades user_id with
-    | Error e -> Template_utils.render_unsafe e request
-    | Ok comrades -> (
-      let comrades =
-        Syntax.unwrap_list
-          (fun id ->
-            match User.get_nick id with
-            | Error _e as e -> e
-            | Ok nick -> Ok (id, nick) )
-          comrades
-      in
-      match comrades with
-      | Error e -> Template_utils.render_unsafe e request
-      | Ok comrades ->
-        let pp_one_discuss fmt (id, nick) =
-          Format.fprintf fmt {|<li><a href="/discuss/%s">%s</a></li>|} id nick
-        in
-        let output =
-          Format.asprintf "<ul>%a</ul>"
-            (Format.pp_print_list
-               ~pp_sep:(fun fmt () -> Format.fprintf fmt "<br />")
-               pp_one_discuss )
-            comrades
-        in
-        Template_utils.render_unsafe output request ) )
+let render =
+  let pp_one_discuss fmt (id, nick) =
+    Format.fprintf fmt {|<li><a href="/discuss/%s">%s</a></li>|} id nick
+  in
+  fun request ->
+    Utils.logged_in_or_redirect request (fun user_id ->
+        Utils.render_result request
+        @@ let* comrades = find_comrades user_id in
+           let* comrades =
+             Syntax.unwrap_list
+               (fun id ->
+                 match User.get_nick id with
+                 | Error _e as e -> e
+                 | Ok nick -> Ok (id, nick) )
+               comrades
+           in
+           Ok
+             (Format.asprintf "<ul>%a</ul>"
+                (Format.pp_print_list
+                   ~pp_sep:(fun fmt () -> Format.fprintf fmt "<br />")
+                   pp_one_discuss )
+                comrades ) )
 
 let pp_discussion (request, user_id, comrade_id) =
   let path = Format.sprintf "/discuss/%s" comrade_id in
-  match find_messages user_id comrade_id with
-  | Error e -> Template_utils.render_unsafe e request
-  | Ok msg -> (
-    match User.get_nick user_id with
-    | Error e -> Template_utils.render_unsafe e request
-    | Ok user_nick -> (
-      match User.get_nick comrade_id with
-      | Error e -> Template_utils.render_unsafe e request
-      | Ok comrade_nick ->
-        let pp_one_msg fmt (from_id, msg) =
-          Format.fprintf fmt "<li>%s | %s</li>"
-            (if from_id = user_id then user_nick else comrade_nick)
-            msg
-        in
-        let pp_all_msg fmt msg =
-          Format.fprintf fmt "<ul>%a</ul>"
-            (Format.pp_print_list
-               ~pp_sep:(fun fmt () -> Format.fprintf fmt "<br />")
-               pp_one_msg )
-            msg
-        in
-        Template_utils.render_unsafe
-          (Format.asprintf
-             {|%a<br />
+  Utils.render_result request
+  @@ let* msg = find_messages user_id comrade_id in
+     let* user_nick = User.get_nick user_id in
+     let* comrade_nick = User.get_nick comrade_id in
+     let pp_one_msg fmt (from_id, msg) =
+       Format.fprintf fmt "<li>%s | %s</li>"
+         (if from_id = user_id then user_nick else comrade_nick)
+         msg
+     in
+     let pp_all_msg fmt msg =
+       Format.fprintf fmt "<ul>%a</ul>"
+         (Format.pp_print_list
+            ~pp_sep:(fun fmt () -> Format.fprintf fmt "<br />")
+            pp_one_msg )
+         msg
+     in
+     Ok
+       (Format.asprintf
+          {|%a<br />
           %s
           <input value="" name="msg" type="text" />
           <button type="submit" class="btn btn-primary">Send</button>
         </form>|}
-             pp_all_msg msg
-             (Dream.form_tag ~action:path request) )
-          request ) )
+          pp_all_msg msg
+          (Dream.form_tag ~action:path request) )
 
 (** display one discussion *)
-let render_one request =
-  let comrade_id = Dream.param request "comrade_id" in
-
-  let path = Format.sprintf "/discuss/%s" comrade_id in
-
-  match Dream.session "user_id" request with
-  | None ->
-    let redirect_url =
-      Format.sprintf "/login=?redirect=%s" (Dream.to_percent_encoded path)
-    in
-    Dream.respond ~status:`See_Other ~headers:[ ("Location", redirect_url) ] ""
-  | Some user_id -> pp_discussion (request, user_id, comrade_id)
+let renderone request =
+  Utils.logged_in_or_redirect request (fun user_id ->
+      let comrade_id = Dream.param request "comrade_id" in
+      pp_discussion (request, user_id, comrade_id) )
 
 let insert_msg from_id to_id msg =
   let open Syntax in
@@ -146,24 +122,15 @@ let insert_msg from_id to_id msg =
 
 (** handle posts *)
 let post request =
-  let comrade_id = Dream.param request "comrade_id" in
-
-  let path = Format.sprintf "/discuss/%s" comrade_id in
-
-  match Dream.session "user_id" request with
-  | None ->
-    let redirect_url =
-      Format.sprintf "/login=?redirect=%s" (Dream.to_percent_encoded path)
-    in
-    Dream.respond ~status:`See_Other ~headers:[ ("Location", redirect_url) ] ""
-  | Some user_id -> (
-    match%lwt Dream.form request with
-    | `Ok [ ("msg", msg) ] -> begin
-      match insert_msg user_id comrade_id msg with
-      | Ok () -> pp_discussion (request, user_id, comrade_id)
-      | Error e -> Template_utils.render_unsafe e request
-    end
-    | `Ok _ -> Dream.respond ~status:`Bad_Request "invalid form"
-    | `Expired _ | `Many_tokens _ | `Missing_token _ | `Invalid_token _
-    | `Wrong_session _ | `Wrong_content_type ->
-      Dream.empty `Bad_Request )
+  Utils.logged_in_or_redirect request (fun user_id ->
+      match%lwt Dream.form request with
+      | `Ok [ ("msg", msg) ] -> begin
+        let comrade_id = Dream.param request "comrade_id" in
+        match insert_msg user_id comrade_id msg with
+        | Ok () -> pp_discussion (request, user_id, comrade_id)
+        | Error e -> Utils.render e request
+      end
+      | `Ok _ -> Dream.respond ~status:`Bad_Request "invalid form"
+      | `Expired _ | `Many_tokens _ | `Missing_token _ | `Invalid_token _
+      | `Wrong_session _ | `Wrong_content_type ->
+        Dream.empty `Bad_Request )