Enter UrlNotFoundMsg iomanipulator-like class

src/server/internalServer.cpp

@@ -387,6 +387,25 @@ SuggestionsList_t getSuggestions(SuggestionSearcherCache& cache, const zim::Arch
   return suggestions;
 }
 
+namespace
+{
+
+class UrlNotFoundMsg {};
+
+const UrlNotFoundMsg urlNotFoundMsg;
+
+ContentResponseBlueprint&& operator+(ContentResponseBlueprint&& crb,
+                                     UrlNotFoundMsg /*unused*/)
+{
+  const std::string requestUrl = crb.m_request.get_full_url();
+  kainjow::mustache::mustache msgTmpl(R"(The requested URL "{{url}}" was not found on this server.)");
+  const auto urlNotFoundMsgText = msgTmpl.render({"url", requestUrl});
+  crb.m_data["details"].push_back({"p", urlNotFoundMsgText});
+  return std::move(crb);
+}
+
+
+} // unnamed namespace
 
 std::unique_ptr<Response> InternalServer::handle_suggest(const RequestContext& request)
 {
@@ -658,7 +677,7 @@ std::unique_ptr<Response> InternalServer::handle_catalog(const RequestContext& r
     url  = request.get_url_part(1);
   } catch (const std::out_of_range&) {
     return make404Response(*this, request)
-           + make404ResponseData(request.get_full_url());
+           + urlNotFoundMsg;
   }
 
   if (url == "v2") {
@@ -666,7 +685,8 @@ std::unique_ptr<Response> InternalServer::handle_catalog(const RequestContext& r
   }
 
   if (url != "searchdescription.xml" && url != "root.xml" && url != "search") {
-    return Response::build_404(*this, request.get_full_url());
+    return make404Response(*this, request)
+           + urlNotFoundMsg;
   }
 
   if (url == "searchdescription.xml") {

src/server/response.cpp

@@ -112,11 +112,14 @@ std::unique_ptr<ContentResponse> Response::build_404(const InternalServer& serve
 ContentResponseBlueprint make404Response(const InternalServer& server,
                                          const RequestContext& request)
 {
-  return ContentResponseBlueprint(&server,
+  auto crb = ContentResponseBlueprint(&server,
-                                  &request,
+                                      &request,
-                                  MHD_HTTP_NOT_FOUND,
+                                      MHD_HTTP_NOT_FOUND,
-                                  "text/html",
+                                      "text/html",
-                                  RESOURCE::templates::_404_html);
+                                      RESOURCE::templates::_404_html);
+
+  kainjow::mustache::list emptyList;
+  return crb + kainjow::mustache::object{{"details", emptyList}};
 }
 
 std::unique_ptr<Response> Response::build_416(const InternalServer& server, size_t resourceLength)

src/server/response.h

@@ -166,7 +166,7 @@ public: // functions
     return operator std::unique_ptr<ContentResponse>();
   }
 
-private: // data
+public: //data
   const InternalServer& m_server;
   const RequestContext& m_request;
   const int m_httpStatusCode;

test/server.cpp

@@ -549,9 +549,6 @@ TEST_F(ServerTest, 404WithBodyTesting)
     <p>
       The requested URL "/ROOT/catalog/" was not found on this server.
     </p>
-    <p>
-      //EOLWHITESPACEMARKER
-    </p>
 )"  },
 
     { /* url */ "/ROOT/catalog/invalid_endpoint",
@@ -560,9 +557,6 @@ TEST_F(ServerTest, 404WithBodyTesting)
     <p>
       The requested URL "/ROOT/catalog/invalid_endpoint" was not found on this server.
     </p>
-    <p>
-      //EOLWHITESPACEMARKER
-    </p>
 )"  },
 
     { /* url */ "/ROOT/invalid-book/whatever",