[C++][Restbed] Add handler callback methods

Created by: muttleyxd

PR checklist

• Read the contribution guidelines.
• Ran the shell script under ./bin/ to update Petstore sample so that CIs can verify the change. (For instance, only need to run ./bin/{LANG}-petstore.sh, ./bin/openapi3/{LANG}-petstore.sh if updating the {LANG} (e.g. php, ruby, python, etc) code generator or {LANG} client's mustache templates). Windows batch files can be found in .\bin\windows\. If contributing template-only or documentation-only changes which will change sample output, be sure to build the project first. Added second commit with updated samples (not 100% sure what I should do with them), are there any tests for these? I didn't find any.
• Filed the PR against the correct branch: master, 4.1.x, 5.0.x. Default: master.
• Copied the technical committee to review the pull request if your PR is targeting a particular programming language. @ravinikam @stkrwork @fvarose @etherealjoy @MartinDelille

Description of the PR

Related issue: #273 What I don't like about current generator: you need to modify generated code, there isn't a way for injecting your own handler. librestbed does not allow to replace already existing handler, which means you either modify generated code or don't use it at all. I modified it a little, to allow setting a callback, which responds with std::pair<int (HTTP status code), std::string (response)>

I'm not an expert on Mustache, so I would be really grateful for some tips where I could optimize/refactor it.

modules/openapi-generator/src/main/resources/cpp-restbed-server/api-header.mustache

@@ -10,6 +10,8 @@
 
 {{{defaultInclude}}}
 #include <memory>
+#include <utility>
+
 #include <corvusoft/restbed/session.hpp>
 #include <corvusoft/restbed/resource.hpp>
 #include <corvusoft/restbed/service.hpp>
@@ -49,6 +51,31 @@ public:
     {{#vendorExtensions.x-codegen-otherMethods}}
     void {{httpMethod}}_method_handler(const std::shared_ptr<restbed::Session> session);
     {{/vendorExtensions.x-codegen-otherMethods}}
+
+	void set_handler_{{httpMethod}}(
+		std::function<std::pair<int, std::string>(
+			{{#allParams}}{{{dataType}}} const &{{#hasMore}}, {{/hasMore}}{{/allParams}}
+		)> handler
+	);
+
+	{{#vendorExtensions.x-codegen-otherMethods}}
+	void set_handler_{{httpMethod}}(
+		std::function<std::pair<int, std::string>(
+			{{#allParams}}{{{dataType}}} const &{{#hasMore}}, {{/hasMore}}{{/allParams}}
+		)> handler
+	);
+	{{/vendorExtensions.x-codegen-otherMethods}}
+
+private:
+	std::function<std::pair<int, std::string>(
+		{{#allParams}}{{{dataType}}} const &{{#hasMore}}, {{/hasMore}}{{/allParams}}
+	)> handler_{{httpMethod}}_;
+
+	{{#vendorExtensions.x-codegen-otherMethods}}
+	std::function<std::pair<int, std::string>(
+		{{#allParams}}{{{dataType}}} const &{{#hasMore}}, {{/hasMore}}{{/allParams}}
+	)> handler_{{httpMethod}}_;
+	{{/vendorExtensions.x-codegen-otherMethods}}
 };
 
 {{/operation}}

modules/openapi-generator/src/main/resources/cpp-restbed-server/api-source.mustache

@@ -54,6 +54,22 @@ void {{classname}}::stopService() {
 {
 }
 
+void {{classname}}{{vendorExtensions.x-codegen-resourceName}}Resource::set_handler_{{httpMethod}}(
+	std::function<std::pair<int, std::string>(
+		{{#allParams}}{{{dataType}}} const &{{#hasMore}}, {{/hasMore}}{{/allParams}}
+	)> handler) {
+	handler_{{httpMethod}}_ = std::move(handler);
+}
+
+{{#vendorExtensions.x-codegen-otherMethods}}
+void {{classname}}{{vendorExtensions.x-codegen-resourceName}}Resource::set_handler_{{httpMethod}}(
+	std::function<std::pair<int, std::string>(
+		{{#allParams}}{{{dataType}}} const &{{#hasMore}}, {{/hasMore}}{{/allParams}}
+	)> handler) {
+	handler_{{httpMethod}}_ = std::move(handler);
+}
+{{/vendorExtensions.x-codegen-otherMethods}}
+
 void {{classname}}{{vendorExtensions.x-codegen-resourceName}}Resource::{{httpMethod}}_method_handler(const std::shared_ptr<restbed::Session> session) {
 
 	const auto request = session->get_request();
@@ -65,12 +81,12 @@ void {{classname}}{{vendorExtensions.x-codegen-resourceName}}Resource::{{httpMet
 		{
 
 			const auto request = session->get_request();
-			std::string requestBody = restbed::String::format("%.*s\n", ( int ) body.size( ), body.data( ));
+			std::string file = restbed::String::format("%.*s\n", ( int ) body.size( ), body.data( ));
 			/**
-			 * Get body params or form params here from the requestBody string
+			 * Get body params or form params here from the file string
 			 */
 	{{/hasBodyParam}}
-			
+
 			{{#hasPathParams}}
 			// Getting the path params
 			{{#pathParams}}
@@ -79,7 +95,7 @@ void {{classname}}{{vendorExtensions.x-codegen-resourceName}}Resource::{{httpMet
 			{{/isPrimitiveType}}
 			{{/pathParams}}
 			{{/hasPathParams}}
-			
+
 			{{#hasQueryParams}}
 			// Getting the query params
 			{{#queryParams}}
@@ -97,21 +113,25 @@ void {{classname}}{{vendorExtensions.x-codegen-resourceName}}Resource::{{httpMet
 			{{/isPrimitiveType}}
 			{{/headerParams}}
 			{{/hasHeaderParams}}
-			
+
 			// Change the value of this variable to the appropriate response before sending the response
 			int status_code = 200;
-			
-			/**
-			 * Process the received information here
-			 */
-			
+			std::string result = "successful operation";
+
+			if (handler_{{httpMethod}}_)
+			{
+				std::tie(status_code, result) = handler_{{httpMethod}}_(
+					{{#allParams}}{{paramName}}{{#hasMore}}, {{/hasMore}}{{/allParams}}
+				);
+			}
+
 			{{#responses}}
 			if (status_code == {{code}}) {
 				{{#headers}}
 				// Description: {{description}}
 				session->set_header("{{baseName}}", ""); // Change second param to your header value
 				{{/headers}}
-				session->close({{code}}, "{{message}}", { {"Connection", "close"} });
+				session->close({{code}}, result.empty() ? "{{message}}" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 			{{/responses}}
@@ -133,7 +153,7 @@ void {{classname}}{{vendorExtensions.x-codegen-resourceName}}Resource::{{httpMet
 		{
 
 			const auto request = session->get_request();
-			std::string requestBody = restbed::String::format("%.*s\n", ( int ) body.size( ), body.data( ));
+			std::string file = restbed::String::format("%.*s\n", ( int ) body.size( ), body.data( ));
 	{{/hasBodyParam}}
 
 			{{#hasPathParams}}
@@ -144,7 +164,7 @@ void {{classname}}{{vendorExtensions.x-codegen-resourceName}}Resource::{{httpMet
 			{{/isPrimitiveType}}
 			{{/pathParams}}
 			{{/hasPathParams}}
-			
+
 			{{#hasQueryParams}}
 			// Getting the query params
 			{{#queryParams}}
@@ -162,14 +182,18 @@ void {{classname}}{{vendorExtensions.x-codegen-resourceName}}Resource::{{httpMet
 			{{/isPrimitiveType}}
 			{{/headerParams}}
 			{{/hasHeaderParams}}
-			
+
 			// Change the value of this variable to the appropriate response before sending the response
 			int status_code = 200;
-			
-			/**
-			 * Process the received information here
-			 */
-			
+			std::string result = "successful operation";
+
+			if (handler_{{httpMethod}}_)
+			{
+				std::tie(status_code, result) = handler_{{httpMethod}}_(
+					{{#allParams}}{{paramName}}{{#hasMore}}, {{/hasMore}}{{/allParams}}
+				);
+			}
+
 			{{#responses}}
 			if (status_code == {{code}}) {
 				{{#baseType}}
@@ -179,7 +203,7 @@ void {{classname}}{{vendorExtensions.x-codegen-resourceName}}Resource::{{httpMet
 				// Description: {{description}}
 				session->set_header("{{baseName}}", ""); // Change second param to your header value
 				{{/headers}}
-				session->close({{code}}, "{{message}}", { {"Connection", "close"} });
+				session->close({{code}}, result.empty() ? "{{message}}" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 			{{/responses}}

samples/server/petstore/cpp-restbed/.openapi-generator/VERSION

-3.3.1-SNAPSHOT
\ No newline at end of file
+4.0.1-SNAPSHOT
\ No newline at end of file

samples/server/petstore/cpp-restbed/api/PetApi.cpp

@@ -2,10 +2,10 @@
  * OpenAPI Petstore
  * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
  *
- * OpenAPI spec version: 1.0.0
+ * The version of the OpenAPI document: 1.0.0
  * 
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 4.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 4.0.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
@@ -72,6 +72,20 @@ PetApiPetResource::~PetApiPetResource()
 {
 }
 
+void PetApiPetResource::set_handler_POST(
+	std::function<std::pair<int, std::string>(
+		std::shared_ptr<Pet> const &
+	)> handler) {
+	handler_POST_ = std::move(handler);
+}
+
+void PetApiPetResource::set_handler_PUT(
+	std::function<std::pair<int, std::string>(
+		std::shared_ptr<Pet> const &
+	)> handler) {
+	handler_PUT_ = std::move(handler);
+}
+
 void PetApiPetResource::POST_method_handler(const std::shared_ptr<restbed::Session> session) {
 
 	const auto request = session->get_request();
@@ -82,23 +96,27 @@ void PetApiPetResource::POST_method_handler(const std::shared_ptr<restbed::Sessi
 		{
 
 			const auto request = session->get_request();
-			std::string requestBody = restbed::String::format("%.*s\n", ( int ) body.size( ), body.data( ));
+			std::string file = restbed::String::format("%.*s\n", ( int ) body.size( ), body.data( ));
 			/**
-			 * Get body params or form params here from the requestBody string
+			 * Get body params or form params here from the file string
 			 */
-			
-			
 
-			
+
+
+
 			// Change the value of this variable to the appropriate response before sending the response
 			int status_code = 200;
-			
-			/**
-			 * Process the received information here
-			 */
-			
+			std::string result = "successful operation";
+
+			if (handler_POST_)
+			{
+				std::tie(status_code, result) = handler_POST_(
+					body
+				);
+			}
+
 			if (status_code == 405) {
-				session->close(405, "Invalid input", { {"Connection", "close"} });
+				session->close(405, result.empty() ? "Invalid input" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 
@@ -115,28 +133,32 @@ void PetApiPetResource::PUT_method_handler(const std::shared_ptr<restbed::Sessio
 		{
 
 			const auto request = session->get_request();
-			std::string requestBody = restbed::String::format("%.*s\n", ( int ) body.size( ), body.data( ));
+			std::string file = restbed::String::format("%.*s\n", ( int ) body.size( ), body.data( ));
+
+
 
-			
 
-			
 			// Change the value of this variable to the appropriate response before sending the response
 			int status_code = 200;
-			
-			/**
-			 * Process the received information here
-			 */
-			
+			std::string result = "successful operation";
+
+			if (handler_PUT_)
+			{
+				std::tie(status_code, result) = handler_PUT_(
+					body
+				);
+			}
+
 			if (status_code == 400) {
-				session->close(400, "Invalid ID supplied", { {"Connection", "close"} });
+				session->close(400, result.empty() ? "Invalid ID supplied" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 			if (status_code == 404) {
-				session->close(404, "Pet not found", { {"Connection", "close"} });
+				session->close(404, result.empty() ? "Pet not found" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 			if (status_code == 405) {
-				session->close(405, "Validation exception", { {"Connection", "close"} });
+				session->close(405, result.empty() ? "Validation exception" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 
@@ -162,26 +184,50 @@ PetApiPetPetIdResource::~PetApiPetPetIdResource()
 {
 }
 
+void PetApiPetPetIdResource::set_handler_DELETE(
+	std::function<std::pair<int, std::string>(
+		int64_t const &, std::string const &
+	)> handler) {
+	handler_DELETE_ = std::move(handler);
+}
+
+void PetApiPetPetIdResource::set_handler_GET(
+	std::function<std::pair<int, std::string>(
+		int64_t const &
+	)> handler) {
+	handler_GET_ = std::move(handler);
+}
+void PetApiPetPetIdResource::set_handler_POST(
+	std::function<std::pair<int, std::string>(
+		int64_t const &, std::string const &, std::string const &
+	)> handler) {
+	handler_POST_ = std::move(handler);
+}
+
 void PetApiPetPetIdResource::DELETE_method_handler(const std::shared_ptr<restbed::Session> session) {
 
 	const auto request = session->get_request();
-			
+
 			// Getting the path params
 			const int64_t petId = request->get_path_parameter("petId", 0L);
-			
+
 
 			// Getting the headers
 			const std::string apiKey = request->get_header("apiKey", "");
-			
+
 			// Change the value of this variable to the appropriate response before sending the response
 			int status_code = 200;
-			
-			/**
-			 * Process the received information here
-			 */
-			
+			std::string result = "successful operation";
+
+			if (handler_DELETE_)
+			{
+				std::tie(status_code, result) = handler_DELETE_(
+					petId, apiKey
+				);
+			}
+
 			if (status_code == 400) {
-				session->close(400, "Invalid pet value", { {"Connection", "close"} });
+				session->close(400, result.empty() ? "Invalid pet value" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 
@@ -193,27 +239,31 @@ void PetApiPetPetIdResource::GET_method_handler(const std::shared_ptr<restbed::S
 
 			// Getting the path params
 			const int64_t petId = request->get_path_parameter("petId", 0L);
-			
 
-			
+
+
 			// Change the value of this variable to the appropriate response before sending the response
 			int status_code = 200;
-			
-			/**
-			 * Process the received information here
-			 */
-			
+			std::string result = "successful operation";
+
+			if (handler_GET_)
+			{
+				std::tie(status_code, result) = handler_GET_(
+					petId
+				);
+			}
+
 			if (status_code == 200) {
 				std::shared_ptr<Pet> response = NULL;
-				session->close(200, "successful operation", { {"Connection", "close"} });
+				session->close(200, result.empty() ? "successful operation" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 			if (status_code == 400) {
-				session->close(400, "Invalid ID supplied", { {"Connection", "close"} });
+				session->close(400, result.empty() ? "Invalid ID supplied" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 			if (status_code == 404) {
-				session->close(404, "Pet not found", { {"Connection", "close"} });
+				session->close(404, result.empty() ? "Pet not found" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 
@@ -224,18 +274,22 @@ void PetApiPetPetIdResource::POST_method_handler(const std::shared_ptr<restbed::
 
 			// Getting the path params
 			const int64_t petId = request->get_path_parameter("petId", 0L);
-			
 
-			
+
+
 			// Change the value of this variable to the appropriate response before sending the response
 			int status_code = 200;
-			
-			/**
-			 * Process the received information here
-			 */
-			
+			std::string result = "successful operation";
+
+			if (handler_POST_)
+			{
+				std::tie(status_code, result) = handler_POST_(
+					petId, name, status
+				);
+			}
+
 			if (status_code == 405) {
-				session->close(405, "Invalid input", { {"Connection", "close"} });
+				session->close(405, result.empty() ? "Invalid input" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 
@@ -254,27 +308,39 @@ PetApiPetFindByStatusResource::~PetApiPetFindByStatusResource()
 {
 }
 
+void PetApiPetFindByStatusResource::set_handler_GET(
+	std::function<std::pair<int, std::string>(
+		std::vector<std::string> const &
+	)> handler) {
+	handler_GET_ = std::move(handler);
+}
+
+
 void PetApiPetFindByStatusResource::GET_method_handler(const std::shared_ptr<restbed::Session> session) {
 
 	const auto request = session->get_request();
-			
-			
+
+
 			// Getting the query params
 
-			
+
 			// Change the value of this variable to the appropriate response before sending the response
 			int status_code = 200;
-			
-			/**
-			 * Process the received information here
-			 */
-			
+			std::string result = "successful operation";
+
+			if (handler_GET_)
+			{
+				std::tie(status_code, result) = handler_GET_(
+					status
+				);
+			}
+
 			if (status_code == 200) {
-				session->close(200, "successful operation", { {"Connection", "close"} });
+				session->close(200, result.empty() ? "successful operation" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 			if (status_code == 400) {
-				session->close(400, "Invalid status value", { {"Connection", "close"} });
+				session->close(400, result.empty() ? "Invalid status value" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 
@@ -294,27 +360,39 @@ PetApiPetFindByTagsResource::~PetApiPetFindByTagsResource()
 {
 }
 
+void PetApiPetFindByTagsResource::set_handler_GET(
+	std::function<std::pair<int, std::string>(
+		std::vector<std::string> const &
+	)> handler) {
+	handler_GET_ = std::move(handler);
+}
+
+
 void PetApiPetFindByTagsResource::GET_method_handler(const std::shared_ptr<restbed::Session> session) {
 
 	const auto request = session->get_request();
-			
-			
+
+
 			// Getting the query params
 
-			
+
 			// Change the value of this variable to the appropriate response before sending the response
 			int status_code = 200;
-			
-			/**
-			 * Process the received information here
-			 */
-			
+			std::string result = "successful operation";
+
+			if (handler_GET_)
+			{
+				std::tie(status_code, result) = handler_GET_(
+					tags
+				);
+			}
+
 			if (status_code == 200) {
-				session->close(200, "successful operation", { {"Connection", "close"} });
+				session->close(200, result.empty() ? "successful operation" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 			if (status_code == 400) {
-				session->close(400, "Invalid tag value", { {"Connection", "close"} });
+				session->close(400, result.empty() ? "Invalid tag value" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 
@@ -334,24 +412,36 @@ PetApiPetPetIdUploadImageResource::~PetApiPetPetIdUploadImageResource()
 {
 }
 
+void PetApiPetPetIdUploadImageResource::set_handler_POST(
+	std::function<std::pair<int, std::string>(
+		int64_t const &, std::string const &, std::string const &
+	)> handler) {
+	handler_POST_ = std::move(handler);
+}
+
+
 void PetApiPetPetIdUploadImageResource::POST_method_handler(const std::shared_ptr<restbed::Session> session) {
 
 	const auto request = session->get_request();
-			
+
 			// Getting the path params
 			const int64_t petId = request->get_path_parameter("petId", 0L);
-			
 
-			
+
+
 			// Change the value of this variable to the appropriate response before sending the response
 			int status_code = 200;
-			
-			/**
-			 * Process the received information here
-			 */
-			
+			std::string result = "successful operation";
+
+			if (handler_POST_)
+			{
+				std::tie(status_code, result) = handler_POST_(
+					petId, additionalMetadata, file
+				);
+			}
+
 			if (status_code == 200) {
-				session->close(200, "successful operation", { {"Connection", "close"} });
+				session->close(200, result.empty() ? "successful operation" : std::move(result), { {"Connection", "close"} });
 				return;
 			}
 

samples/server/petstore/cpp-restbed/api/PetApi.h

@@ -2,10 +2,10 @@
  * OpenAPI Petstore
  * This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.
  *
- * OpenAPI spec version: 1.0.0
+ * The version of the OpenAPI document: 1.0.0
  * 
  *
- * NOTE: This class is auto generated by OpenAPI-Generator 4.0.0-SNAPSHOT.
+ * NOTE: This class is auto generated by OpenAPI-Generator 4.0.1-SNAPSHOT.
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
@@ -21,6 +21,8 @@
 
 
 #include <memory>
+#include <utility>
+
 #include <corvusoft/restbed/session.hpp>
 #include <corvusoft/restbed/resource.hpp>
 #include <corvusoft/restbed/service.hpp>
@@ -59,6 +61,27 @@ public:
     virtual ~PetApiPetResource();
     void POST_method_handler(const std::shared_ptr<restbed::Session> session);
     void PUT_method_handler(const std::shared_ptr<restbed::Session> session);
+
+	void set_handler_POST(
+		std::function<std::pair<int, std::string>(
+			std::shared_ptr<Pet> const &
+		)> handler
+	);
+
+	void set_handler_PUT(
+		std::function<std::pair<int, std::string>(
+			std::shared_ptr<Pet> const &
+		)> handler
+	);
+
+private:
+	std::function<std::pair<int, std::string>(
+		std::shared_ptr<Pet> const &
+	)> handler_POST_;
+
+	std::function<std::pair<int, std::string>(
+		std::shared_ptr<Pet> const &
+	)> handler_PUT_;
 };
 
 /// <summary>
@@ -75,6 +98,35 @@ public:
     void DELETE_method_handler(const std::shared_ptr<restbed::Session> session);
     void GET_method_handler(const std::shared_ptr<restbed::Session> session);
     void POST_method_handler(const std::shared_ptr<restbed::Session> session);
+
+	void set_handler_DELETE(
+		std::function<std::pair<int, std::string>(
+			int64_t const &, std::string const &
+		)> handler
+	);
+
+	void set_handler_GET(
+		std::function<std::pair<int, std::string>(
+			int64_t const &
+		)> handler
+	);
+	void set_handler_POST(
+		std::function<std::pair<int, std::string>(
+			int64_t const &, std::string const &, std::string const &
+		)> handler
+	);
+
+private:
+	std::function<std::pair<int, std::string>(
+		int64_t const &, std::string const &
+	)> handler_DELETE_;
+
+	std::function<std::pair<int, std::string>(
+		int64_t const &
+	)> handler_GET_;
+	std::function<std::pair<int, std::string>(
+		int64_t const &, std::string const &, std::string const &
+	)> handler_POST_;
 };
 
 /// <summary>
@@ -89,6 +141,19 @@ public:
 	PetApiPetFindByStatusResource();
     virtual ~PetApiPetFindByStatusResource();
     void GET_method_handler(const std::shared_ptr<restbed::Session> session);
+
+	void set_handler_GET(
+		std::function<std::pair<int, std::string>(
+			std::vector<std::string> const &
+		)> handler
+	);
+
+
+private:
+	std::function<std::pair<int, std::string>(
+		std::vector<std::string> const &
+	)> handler_GET_;
+
 };
 
 /// <summary>
@@ -103,6 +168,19 @@ public:
 	PetApiPetFindByTagsResource();
     virtual ~PetApiPetFindByTagsResource();
     void GET_method_handler(const std::shared_ptr<restbed::Session> session);
+
+	void set_handler_GET(
+		std::function<std::pair<int, std::string>(
+			std::vector<std::string> const &
+		)> handler
+	);
+
+
+private:
+	std::function<std::pair<int, std::string>(
+		std::vector<std::string> const &
+	)> handler_GET_;
+
 };
 
 /// <summary>
@@ -117,6 +195,19 @@ public:
 	PetApiPetPetIdUploadImageResource();
     virtual ~PetApiPetPetIdUploadImageResource();
     void POST_method_handler(const std::shared_ptr<restbed::Session> session);
+
+	void set_handler_POST(
+		std::function<std::pair<int, std::string>(
+			int64_t const &, std::string const &, std::string const &
+		)> handler
+	);
+
+
+private:
+	std::function<std::pair<int, std::string>(
+		int64_t const &, std::string const &, std::string const &
+	)> handler_POST_;
+
 };