mjsonrpc_user.cxx

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/********************************************************************\
 
  Name:         mjsonrpc_user.cxx
  Created by:   Konstantin Olchanski
 
  Contents:     handler of user-provided and experimental JSON-RPC requests
 
\********************************************************************/
 
#include <stdio.h>
 
#include "mjsonrpc.h"
 
//
// example 1: extract request parameters, return up to 3 results
//
 
static MJsonNode* user_example1(const MJsonNode* params)
{
   if (!params) {
      MJSO* doc = MJSO::I();
      doc->D("example of user defined RPC method that returns up to 3 results");
      doc->P("arg", MJSON_STRING, "example string argment");
      doc->P("optional_arg?", MJSON_INT, "optional example integer argument");
      doc->R("string", MJSON_STRING, "returns the value of \"arg\" parameter");
      doc->R("integer", MJSON_INT, "returns the value of \"optional_arg\" parameter");
      return doc;
   }
 
   MJsonNode* error = NULL;
 
   std::string arg  = mjsonrpc_get_param(params, "arg", &error)->GetString(); if (error) return error;
   int optional_arg = mjsonrpc_get_param(params, "optional_arg", NULL)->GetInt();
 
   if (mjsonrpc_debug)
      printf("user_example1(%s,%d)\n", arg.c_str(), optional_arg);
 
   return mjsonrpc_make_result("string", MJsonNode::MakeString(arg.c_str()), "integer", MJsonNode::MakeInt(optional_arg));
}
 
//
// example 2: extract request parameters, return more than 3 results
//
 
static MJsonNode* user_example2(const MJsonNode* params)
{
   if (!params) {
      MJSO* doc = MJSO::I();
      doc->D("example of user defined RPC method that returns more than 3 results");
      doc->P("arg", MJSON_STRING, "example string argment");
      doc->P("optional_arg?", MJSON_INT, "optional example integer argument");
      doc->R("string1", MJSON_STRING, "returns the value of \"arg\" parameter");
      doc->R("string2", MJSON_STRING, "returns \"hello\"");
      doc->R("string3", MJSON_STRING, "returns \"world!\"");
      doc->R("value1", MJSON_INT, "returns the value of \"optional_arg\" parameter");
      doc->R("value2", MJSON_NUMBER, "returns 3.14");
      return doc;
   }
 
   MJsonNode* error = NULL;
 
   std::string arg  = mjsonrpc_get_param(params, "arg", &error)->GetString(); if (error) return error;
   int optional_arg = mjsonrpc_get_param(params, "optional_arg", NULL)->GetInt();
 
   if (mjsonrpc_debug)
      printf("user_example2(%s,%d)\n", arg.c_str(), optional_arg);
 
   MJsonNode* result = MJsonNode::MakeObject();
 
   result->AddToObject("string1", MJsonNode::MakeString(arg.c_str()));
   result->AddToObject("string2", MJsonNode::MakeString("hello"));
   result->AddToObject("string3", MJsonNode::MakeString("world!"));
   result->AddToObject("value1", MJsonNode::MakeInt(optional_arg));
   result->AddToObject("value2", MJsonNode::MakeNumber(3.14));
 
   return mjsonrpc_make_result(result);
}
 
//
// example 3: return an error
//
 
static MJsonNode* user_example3(const MJsonNode* params)
{
   if (!params) {
      MJSO* doc = MJSO::I();
      doc->D("example of user defined RPC method that returns an error");
      doc->P("arg", MJSON_INT, "integer value, if zero, throws a JSON-RPC error");
      doc->R("status", MJSON_INT, "returns the value of \"arg\" parameter");
      return doc;
   }
 
   MJsonNode* error = NULL;
 
   int arg  = mjsonrpc_get_param(params, "arg", &error)->GetInt(); if (error) return error;
 
   if (mjsonrpc_debug)
      printf("user_example3(%d)\n", arg);
 
   if (arg)
      return mjsonrpc_make_result("status", MJsonNode::MakeInt(arg));
   else
      return mjsonrpc_make_error(15, "example error message", "example error data");
}
 
//
// to create your own rpc method handler, copy one of the examples here, register it in user_init below
//
 
 
 
//
// user_init function is called at startup time to register user rpc method handlers
//
 
void mjsonrpc_user_init()
{
   if (mjsonrpc_debug) {
      printf("mjsonrpc_user_init!\n");
   }
 
   // add user functions to the rpc list
 
   mjsonrpc_add_handler("user_example1", user_example1);
   mjsonrpc_add_handler("user_example2", user_example2);
   mjsonrpc_add_handler("user_example3", user_example3);
}
 
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