Introduce support for asynchronous server-side methods (#12)

* Add preliminary changes for async server methods

* Refactor the Message concept and break it into distinctive types

* Continue working on async server methods (high-level API mainly)

* Continue developing support for async server

* Finishing async server methods

* Finishing async server methods (fixing tests & cleaning up)

* A little code cleaning

* Add unit tests for type traits of free functions

* Support for generating async server methods in stub headers

* Update ChangeLog for v0.3.0

* Update the tutorial with how to use async server-side methods

* Update the TOC in sdbus-c++ tutorial

* Update numbering in TOC

* Remove unnecessary code

* Final cleanups

stub-generator/AdaptorGenerator.cpp

@@ -136,25 +136,47 @@ std::tuple<std::string, std::string> AdaptorGenerator::processMethods(const Node
     {
         auto methodName = method->get("name");
 
+        bool async{false};
+        Nodes annotations = (*method)["annotation"];
+
+        for (const auto& annotation : annotations)
+        {
+            if (annotation->get("name") == "org.freedesktop.DBus.Method.Async"
+                && (annotation->get("value") == "server" || annotation->get("value") == "clientserver"))
+            {
+                async = true;
+                break;
+            }
+        }
+
         Nodes args = (*method)["arg"];
         Nodes inArgs = args.select("direction" , "in");
         Nodes outArgs = args.select("direction" , "out");
 
         std::string argStr, argTypeStr;
         std::tie(argStr, argTypeStr, std::ignore) = argsToNamesAndTypes(inArgs);
+        
+        using namespace std::string_literals;
 
         registrationSS << tab << tab << "object_.registerMethod(\""
                 << methodName << "\")"
                 << ".onInterface(interfaceName)"
                 << ".implementedAs("
                 << "[this]("
+                << (async ? "sdbus::Result<" + outArgsToType(outArgs, true) + "> result" + (argTypeStr.empty() ? "" : ", ") : "")
                 << argTypeStr
-                << "){ return this->" << methodName << "("
+                << "){ " << (async ? "" : "return ") << "this->" << methodName << "("
+                << (async ? "std::move(result)"s + (argTypeStr.empty() ? "" : ", ") : "")
                 << argStr << "); });" << endl;
 
         declarationSS << tab
-                << "virtual " << outArgsToType(outArgs) << " " << methodName
-                << "(" << argTypeStr << ") = 0;" << endl;
+                << "virtual "
+                << (async ? "void" : outArgsToType(outArgs))
+                << " " << methodName
+                << "("
+                << (async ? "sdbus::Result<" + outArgsToType(outArgs, true) + "> result" + (argTypeStr.empty() ? "" : ", ") : "")
+                << argTypeStr
+                << ") = 0;" << endl;
     }
 
     return std::make_tuple(registrationSS.str(), declarationSS.str());

stub-generator/BaseGenerator.cpp

@@ -126,12 +126,15 @@ std::tuple<std::string, std::string, std::string> BaseGenerator::argsToNamesAndT
 /**
  *
  */
-std::string BaseGenerator::outArgsToType(const Nodes& args) const
+std::string BaseGenerator::outArgsToType(const Nodes& args, bool bareList) const
 {
     std::ostringstream retTypeSS;
 
     if (args.size() == 0)
     {
+        if (bareList)
+            return "";
+
         retTypeSS << "void";
     }
     else if (args.size() == 1)
@@ -141,7 +144,8 @@ std::string BaseGenerator::outArgsToType(const Nodes& args) const
     }
     else if (args.size() >= 2)
     {
-        retTypeSS << "std::tuple<";
+        if (!bareList)
+            retTypeSS << "std::tuple<";
 
         bool firstArg = true;
         for (const auto& arg : args)
@@ -150,7 +154,8 @@ std::string BaseGenerator::outArgsToType(const Nodes& args) const
             retTypeSS << signature_to_type(arg->get("type"));
         }
 
-        retTypeSS << ">";
+        if (!bareList)
+            retTypeSS << ">";
     }
 
     return retTypeSS.str();

stub-generator/BaseGenerator.h

@@ -94,7 +94,7 @@ protected:
      * @param args
      * @return return type
      */
-    std::string outArgsToType(const sdbuscpp::xml::Nodes& args) const;
+    std::string outArgsToType(const sdbuscpp::xml::Nodes& args, bool bareList = false) const;
 
 };
 

stub-generator/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required (VERSION 3.3)
+cmake_minimum_required (VERSION 3.4)
 
 add_definitions(-std=c++14)