New feature: functional callbacks

[fhessel]

Allow to use std::functional or std::bind to be used with ResourceNodes.

Needs a bit of testing before merging.

References

• Closes #90

[wubbl0rz]

tested this PR today on an esp32 ttgo t-display. works greats 😄
used your example code from: issue

i tried wrapping my OTA code inside a class and couldn't get it to work without static methods or functions outside of the class. but with this PR everything just works.

secureServer = new HTTPSServer(cert, port, 5);

HTTPSCallbackFunction updateCallback =
    std::bind(&UpdateServer::handleUpdate, this, std::placeholders::_1, std::placeholders::_2);

ResourceNode *updateNode = new ResourceNode("/update", "POST", updateCallback);
secureServer->registerNode(updateNode);
secureServer->start();

[dethegeek]

Hi

I also tried to use your PR with success, but it would be also useful to implement middlewares as methods of a class.

I tried to do this myself, but I needed to implement methods callbacks also for middlewares. As i used this PR as base branch, I think it is better to share a diff here for review. Please note that some changes are untested (the operator==, removal of middlewares and old middlewares implementation.

diff --git a/src/HTTPMiddlewareFunction.hpp b/src/HTTPMiddlewareFunction.hpp
index e8b7cec..d0384b5 100644
--- a/src/HTTPMiddlewareFunction.hpp
+++ b/src/HTTPMiddlewareFunction.hpp
@@ -21,6 +21,8 @@ namespace httpsserver {
    * handling in case of missing authentication. Don't forget to call next in case you want to access your
    * resources, though.
    */
-  typedef void (HTTPSMiddlewareFunction)(HTTPRequest * req, HTTPResponse * res, std::function<void()> next);
+  typedef std::function<void(HTTPRequest * req, HTTPResponse * res, std::function<void()> next)> HTTPSMiddlewareFunction;
+
+  bool operator==(const HTTPSMiddlewareFunction& lhs, const HTTPSMiddlewareFunction& rhs);
 }
  #endif /* SRC_HTTPMIDDLEWAREFUNCTION_HPP_ */
diff --git a/src/ResourceResolver.cpp b/src/ResourceResolver.cpp
index 6eab51d..932eb94 100644
--- a/src/ResourceResolver.cpp
+++ b/src/ResourceResolver.cpp
@@ -160,15 +160,23 @@ void ResourceResolver::resolveNode(const std::string &method, const std::string
   }
 }
 
-void ResourceResolver::addMiddleware(const HTTPSMiddlewareFunction * mwFunction) {
+void ResourceResolver::addMiddleware(const HTTPSMiddlewareFunction mwFunction) {
   _middleware.push_back(mwFunction);
 }
 
-void ResourceResolver::removeMiddleware(const HTTPSMiddlewareFunction * mwFunction) {
+void ResourceResolver::addMiddleware(void (*mwFunction)(HTTPRequest * req, HTTPResponse * res, std::function<void()> next)) {
+  _middleware.push_back(HTTPSMiddlewareFunction(mwFunction));
+}
+
+void ResourceResolver::removeMiddleware(const HTTPSMiddlewareFunction mwFunction) {
+  _middleware.erase(std::remove(_middleware.begin(), _middleware.end(), mwFunction), _middleware.end());
+}
+
+void ResourceResolver::removeMiddleware(void (*mwFunction)(HTTPRequest * req, HTTPResponse * res, std::function<void()> next)) {
   _middleware.erase(std::remove(_middleware.begin(), _middleware.end(), mwFunction), _middleware.end());
 }
 
-const std::vector<HTTPSMiddlewareFunction*> ResourceResolver::getMiddleware() {
+const std::vector<HTTPSMiddlewareFunction> ResourceResolver::getMiddleware() {
   return _middleware;
 }
 
diff --git a/src/ResourceResolver.hpp b/src/ResourceResolver.hpp
index cb67e7f..212457e 100644
--- a/src/ResourceResolver.hpp
+++ b/src/ResourceResolver.hpp
@@ -30,11 +30,13 @@ public:
   void resolveNode(const std::string &method, const std::string &url, ResolvedResource &resolvedResource, HTTPNodeType nodeType);
 
   /** Add a middleware function to the end of the middleware function chain. See HTTPSMiddlewareFunction.hpp for details. */
-  void addMiddleware(const HTTPSMiddlewareFunction * mwFunction);
+  void addMiddleware(const HTTPSMiddlewareFunction mwFunction);
+  void addMiddleware(void (*mwFunction)(HTTPRequest *req, HTTPResponse *res, std::function<void()> next));
   /** Remove a specific function from the middleware function chain. */
-  void removeMiddleware(const HTTPSMiddlewareFunction * mwFunction);
+  void removeMiddleware(const HTTPSMiddlewareFunction mwFunction);
+  void removeMiddleware(void (*mwFunction)(HTTPRequest * req, HTTPResponse * res, std::function<void()> next));
   /** Get the current middleware chain with a resource function at the end */
-  const std::vector<HTTPSMiddlewareFunction*> getMiddleware();
+  const std::vector<HTTPSMiddlewareFunction> getMiddleware();
 
 private:
 
@@ -43,7 +45,7 @@ private:
   HTTPNode * _defaultNode;
 
   // Middleware functions, if any are registered. Will be called in order of the vector.
-  std::vector<const HTTPSMiddlewareFunction*> _middleware;
+  std::vector<HTTPSMiddlewareFunction> _middleware;
 };
 
 } /* namespace httpsserver */

[Regela]

That about other callbacks? For example, https://github.com/fhessel/esp32_https_server/blob/c7e98a6fdb98a033f9df26cf165583d3e0840956/src/WebsocketNode.hpp#L11

[flohoss]

Hi, need functional callbacks for a project, PR is fixing it. Is this going to be merged any time soon? Awesome Work! Got the server up in no time.

[trullock]

Whats the chances of getting this moved along? Really need this

Happy to help