New feature: functional callbacks

Author: fhessel

Diff for: src/HTTPConnection.cpp

@@ -481,10 +481,10 @@ void HTTPConnection::loop() {
           }
 
           // Find the request handler callback
-          HTTPSCallbackFunction * resourceCallback;
+          HTTPSCallbackFunction resourceCallback;
           if (websocketRequested) {
             // For the websocket, we use the handshake callback defined below
-            resourceCallback = &handleWebsocketHandshake;
+            resourceCallback = HTTPSCallbackFunction(&handleWebsocketHandshake);
           } else {
             // For resource nodes, we use the callback defined by the node itself
             resourceCallback = ((ResourceNode*)resolvedResource.getMatchingNode())->_callback;

Diff for: src/HTTPSCallbackFunction.hpp

@@ -1,14 +1,16 @@
 #ifndef SRC_HTTPSCALLBACKFUNCTION_HPP_
 #define SRC_HTTPSCALLBACKFUNCTION_HPP_
 
+#include <functional>
+
 #include "HTTPRequest.hpp"
 #include "HTTPResponse.hpp"
 
 namespace httpsserver {
   /**
    * \brief A callback function that will be called by the server to handle a request
    */
-  typedef void (HTTPSCallbackFunction)(HTTPRequest * req, HTTPResponse * res);
+  typedef std::function<void(HTTPRequest *, HTTPResponse *)> HTTPSCallbackFunction;
 }
 
 #endif /* SRC_HTTPSCALLBACKFUNCTION_HPP_ */

Diff for: src/ResourceNode.cpp

@@ -2,13 +2,20 @@
 
 namespace httpsserver {
 
-ResourceNode::ResourceNode(const std::string &path, const std::string &method, const HTTPSCallbackFunction * callback, const std::string &tag):
+ResourceNode::ResourceNode(const std::string &path, const std::string &method, const HTTPSCallbackFunction callback, const std::string &tag):
   HTTPNode(path, HANDLER_CALLBACK, tag),
   _method(method),
   _callback(callback) {
 
 }
 
+ResourceNode::ResourceNode(const std::string &path, const std::string &method, void (*callback)(HTTPRequest * req, HTTPResponse * res), const std::string &tag):
+  HTTPNode(path, HANDLER_CALLBACK, tag),
+  _method(method),
+  _callback(HTTPSCallbackFunction(callback)) {
+
+}
+
 ResourceNode::~ResourceNode() {
 
 }

Diff for: src/ResourceNode.hpp

@@ -10,16 +10,35 @@ namespace httpsserver {
 
 /**
  * \brief This HTTPNode represents a route that maps to a regular HTTP request for a resource (static or dynamic)
- * 
+ *
  * It therefore contrasts to the WebsocketNode, which handles requests for Websockets.
  */
 class ResourceNode : public HTTPNode {
 public:
-  ResourceNode(const std::string &path, const std::string &method, const HTTPSCallbackFunction * callback, const std::string &tag = "");
+  /**
+   * \brief Create the Resource Node with C++-Style functional attribute.
+   *
+   * This variant is more flexible and allows to use std::bind for example to call class member functions.
+   *
+   * \param path The path/route to register the handler to, e.g. "/config"
+   * \param method The method required to match this node, e.g. "GET"
+   * \param callback The function to call when the route is accessed
+   * \param tag Optional tag that can be accessed in the handler function. Use it for example to define the roles required to access this route
+   */
+  ResourceNode(const std::string &path, const std::string &method, const HTTPSCallbackFunction callback, const std::string &tag = "");
+  /**
+   * \brief Create the Resource Node with a C-Style function pointer.
+   *
+   * \param path The path/route to register the handler to, e.g. "/config"
+   * \param method The method required to match this node, e.g. "GET"
+   * \param callback The function callback. Must return void, first parameter is a pointer to a HTTPRequest, second a pointer to a HTTPResponse
+   * \param tag Optional tag that can be accessed in the handler function. Use it for example to define the roles required to access this route
+   */
+  ResourceNode(const std::string &path, const std::string &method, void (*const callback)(HTTPRequest * req, HTTPResponse * res), const std::string &tag = "");
   virtual ~ResourceNode();
 
   const std::string _method;
-  const HTTPSCallbackFunction * _callback;
+  const HTTPSCallbackFunction _callback;
   std::string getMethod() { return _method; }
 };