glz::rpc:make_schema_methods

[arturbac]

Are You interested in adding helper function for getting rpc server schema info overview for for example generating web page with API or for returning this API info to client.
If yes what should I change or add...

namespace glz::rpc
  {
struct schema_method_t
  {
  std::string_view method_name;
  std::string params;
  std::string result;
  };

template<typename method>
auto schema_method_info() -> schema_method_t
  {
  schema_method_t result{
    .method_name = method::name_v,
    .params = glz::write_json_schema<typename method::params_t>(),
    .result = glz::write_json_schema<typename method::result_t>()
  };
  return result;
  }

template<typename... Methods>
auto make_schema_methods_array(glz::tuplet::tuple<Methods...> const &)
  {
  auto construct_schema_method = [](auto method_instance) -> schema_method_t
  {
    using MethodType = decltype(method_instance);
    return schema_method_info<MethodType>();
  };
  return std::array<schema_method_t, sizeof...(Methods)>{construct_schema_method(Methods{})...};
  }


template<typename... Methods>
auto make_schema_methods(glz::tuplet::tuple<Methods...> methods)
  {
  return make_schema_methods_array(methods);
  }
  }  // namespace glz::rpc
  
  
  
struct complex_request_t
  {
  Color color;
  test_data_t data;
  int value;
  std::string name;
  };

struct complex_response_t
  {
  Color color;
  test_enum_e enum_field;
  int value;
  std::string name;
  };
int main()
  {
  using complex_method = glz::rpc::method<"complex_method", complex_request_t, complex_response_t>;
  using test_method = glz::rpc::method<"test_data_t", test_data_t, test_data_t>;
  using server_type = glz::rpc::server<complex_method,test_method>;
  server_type server;
  
  std::array schema_methods {glz::rpc::make_schema_methods( server.methods )};
  for( glz::rpc::schema_method_t method : schema_methods )
    std::cout << method.method_name << "\n"
    << "\t" << method.params << "\n" 
    << "\t" << method.result << "\n";

complex_method
	{"type":["object"],"properties":{"color":{"$ref":"#/$defs/Color"},"data":{"$ref":"#/$defs/test_data_t"},"name":{"$ref":"#/$defs/std::string"},"value":{"$ref":"#/$defs/int32_t"}},"additionalProperties":false,"$defs":{"Color":{"type":["string"],"oneOf":[{"const":"Red"},{"const":"Green"},{"const":"Blue"}]},"int32_t":{"type":["integer"]},"std::string":{"type":["string"]},"test_data_t":{"type":["object"],"properties":{"enum_field":{"$ref":"#/$defs/test_enum_e"}},"additionalProperties":false},"test_enum_e":{"type":["string"],"oneOf":[{"const":"foo"},{"const":"bar"},{"const":"baz"}]}}}
	{"type":["object"],"properties":{"color":{"$ref":"#/$defs/Color"},"enum_field":{"$ref":"#/$defs/test_enum_e"},"name":{"$ref":"#/$defs/std::string"},"value":{"$ref":"#/$defs/int32_t"}},"additionalProperties":false,"$defs":{"Color":{"type":["string"],"oneOf":[{"const":"Red"},{"const":"Green"},{"const":"Blue"}]},"int32_t":{"type":["integer"]},"std::string":{"type":["string"]},"test_enum_e":{"type":["string"],"oneOf":[{"const":"foo"},{"const":"bar"},{"const":"baz"}]}}}
test_data_t
	{"type":["object"],"properties":{"enum_field":{"$ref":"#/$defs/test_enum_e"}},"additionalProperties":false,"$defs":{"test_enum_e":{"type":["string"],"oneOf":[{"const":"foo"},{"const":"bar"},{"const":"baz"}]}}}
	{"type":["object"],"properties":{"enum_field":{"$ref":"#/$defs/test_enum_e"}},"additionalProperties":false,"$defs":{"test_enum_e":{"type":["string"],"oneOf":[{"const":"foo"},{"const":"bar"},{"const":"baz"}]}}}

[arturbac]

I then can be used to generate for example postman-collection on server for autmatic methods name enumeration

{
  "info": {
    "_postman_id": "unique-collection-id",
    "name": "JSON-RPC 2.0 Simple Collection",
    "schema": "https://schema.getpostman.com/json/collection/v2.1.0/collection.json"
  },
  "item": [
    {
      "name": "sumNumbers",
      "request": {
        "method": "POST",
        "header": [
          {
            "key": "Content-Type",
            "value": "application/json"
          }
        ],
        "body": {
          "mode": "raw",
          "raw": "{\"jsonrpc\": \"2.0\", \"method\": \"sumNumbers\", \"params\": [5, 12], \"id\": 1}"
        },
        "url": {
          "raw": "{{url}}/jsonrpc",
          "host": [
            "{{url}}"
          ],
          "path": [
            "jsonrpc"
          ]
        }
      },
      "response": [
        {
          "name": "Success Response",
          "code": 200,
          "_postman_previewlanguage": "json",
          "body": "{\"jsonrpc\": \"2.0\", \"result\": 17, \"id\": 1}"
        }
      ]
    },
    {
      "name": "getUser",
      "request": {
        "method": "POST",
        "header": [
          {
            "key": "Content-Type",
            "value": "application/json"
          }
        ],
        "body": {
          "mode": "raw",
          "raw": "{\"jsonrpc\": \"2.0\", \"method\": \"getUser\", \"params\": {\"userId\": \"abc123\"}, \"id\": 2}"
        },
        "url": {
          "raw": "{{url}}/jsonrpc",
          "host": [
            "{{url}}"
          ],
          "path": [
            "jsonrpc"
          ]
        }
      },
      "response": [
        {
          "name": "Success Response",
          "code": 200,
          "_postman_previewlanguage": "json",
          "body": "{\"jsonrpc\": \"2.0\", \"result\": {\"name\": \"John Doe\", \"age\": 30}, \"id\": 2}"
        }
      ]
    }
  ]
}

[stephenberry]

Nice! I like this a lot and would gladly add it to glaze. Have you looked into glz::write_json_schema (internals are glz::detail::to_json_schema? We should be able to serialize std::array schema_methods from your example using glz::write_json_schema. If you make a pull request for this stuff, I would merge it in.