Added HTTP client base that enables SM to make async HTTP requests and receive the responses as callbacks accessable by client behaviors

Author: yassiezar

smacc/include/smacc/client_bases/smacc_http_client.h

@@ -0,0 +1,92 @@
+#pragma once
+
+#include <cpr/cpr.h>  // Make sure this header is available in your include path
+#include <smacc/impl/smacc_state_impl.h>
+#include <smacc/smacc_client.h>
+
+#include <boost/optional/optional_io.hpp>
+
+namespace smacc {
+namespace client_bases {
+
+class SmaccHttpClient : public smacc::ISmaccClient {
+ public:
+  boost::optional<std::string> serverName;
+  boost::optional<int> timeout;
+
+  SmaccHttpClient() { initialized_ = false; }
+
+  SmaccHttpClient(const std::string &serverName, const int &timeout) {
+    this->serverName = serverName;
+    this->timeout = timeout;
+  }
+
+  smacc::SmaccSignal<void(const cpr::Response &)> onResponseReceived_;
+
+  template <typename T>
+  boost::signals2::connection onResponseReceived(
+      void (T::*callback)(const cpr::Response &), T *object) {
+    return this->getStateMachine()->createSignalConnection(onResponseReceived_,
+                                                           callback, object);
+  }
+
+  template <typename TOrthogonal, typename TSourceObject>
+  void onOrthogonalAllocation() {}
+
+  virtual void initialize() {
+    if (!initialized_) {
+      if (!timeout) timeout = 2000;  // 2s timeout default
+      if (!serverName) {
+        ROS_ERROR("Server URL not set, skipping initialisation");
+      } else {
+        ROS_INFO_STREAM("[" << this->getName()
+                            << "] Initialising HTTP client for " << serverName);
+        initialized_ = true;
+      }
+    }
+  }
+
+  // cpr::Header is an STL map-like object mapping string key-value pairs,
+  // e.g. {"Content-Type", "application/json"}
+  void makePostRequest(const std::string &path, const std::string &body,
+                   const cpr::Header &header) {
+    if (!initialized_) {
+      ROS_ERROR("%s: not initialized.", this->getName().c_str());
+      return;
+    }
+    if (!serverName) {
+      ROS_ERROR("Server URL not set.");
+      return;
+    }
+    request_ = cpr::PostCallback(
+        [this](const cpr::Response &response) {
+          onResponseReceived_(response);
+        },
+        cpr::Url{serverName.get() + path}, cpr::Body{{body}},
+        cpr::Header{header}, cpr::Timeout{timeout.get()});
+  }
+
+  void makeGetRequest(const std::string &path, const std::string &body = "",
+                   const cpr::Header &header = {}) {
+    if (!initialized_) {
+      ROS_ERROR("%s: not initialized.", this->getName().c_str());
+      return;
+    }
+    if (!serverName) {
+      ROS_ERROR("Server URL not set.");
+      return;
+    }
+    request_ = cpr::GetCallback(
+        [this](const cpr::Response &response) {
+          onResponseReceived_(response);
+        },
+        cpr::Url{serverName.get() + path}, cpr::Body{{body}},
+        cpr::Header{header}, cpr::Timeout{timeout.get()});
+  }
+
+ private:
+  bool initialized_;
+  std::future<void> request_;
+};
+}  // namespace client_bases
+}  // namespace smacc