Allow callback when request disconnects (me-no-dev#284)

* Allow callback when request disconnects

* Use typedef std::function<void(void)> ArDisconnectHandler

Author: Luc

src/ESPAsyncWebServer.h

@@ -62,6 +62,7 @@ typedef enum {
   HTTP_ANY     = 0b01111111,
 } WebRequestMethod;
 typedef uint8_t WebRequestMethodComposite;
+typedef std::function<void(void)> ArDisconnectHandler;
 
 /*
  * PARAMETER :: Chainable object to hold GET/POST and FILE parameters
@@ -128,6 +129,7 @@ class AsyncWebServerRequest {
     AsyncWebHandler* _handler;
     AsyncWebServerResponse* _response;
     StringArray _interestingHeaders;
+    ArDisconnectHandler _onDisconnectfn;
 
     String _temp;
     uint8_t _parseState;
@@ -202,6 +204,7 @@ class AsyncWebServerRequest {
     const char * requestedConnTypeToString() const;
     RequestedConnectionType requestedConnType() const { return _reqconntype; }
     bool isExpectedRequestedConnType(RequestedConnectionType erct1, RequestedConnectionType erct2 = RCT_NOT_USED, RequestedConnectionType erct3 = RCT_NOT_USED);
+    void onDisconnect (ArDisconnectHandler fn);
 
     //hash is the string representation of:
     // base64(user:pass) for basic or

src/WebRequest.cpp

@@ -214,8 +214,15 @@ void AsyncWebServerRequest::_onTimeout(uint32_t time){
   _client->close();
 }
 
+void AsyncWebServerRequest::onDisconnect (ArDisconnectHandler fn){
+    _onDisconnectfn=fn;
+}
+
 void AsyncWebServerRequest::_onDisconnect(){
   //os_printf("d\n");
+  if(_onDisconnectfn) {
+      _onDisconnectfn();
+    }
   _server->_handleDisconnect(this);
 }