Errors while building on eosstudio

Question

I tried the below code from a tutorial of a simple eos contract on a game but i get 10 errors while building it on eosstudio wasted a lot of time trying to figure the errors out but failed appreciate if anyone can help Thank you

#include <mygame.hpp>
#include <string>

using namespace eosio;
using std::string;

class mygame : public contract {

  using contract::contract;

  public:
  // mygame( name self ) : contract(self){}

  ///@abi action
  void add(const name account, string& username, uint64_t level){

    require_auth(account);
    playerIndex players(_self,_self);
    // address_index addresses(_self, _self.value);

    auto iterator = players.find(account);
    eosio_assert(iterator == players.end(), "Address of account already exists")

    players.emplace(account,[&] (auto& player){
      player.account_name = account;
      player.username = username;
      player.level = 1;
      player.health = 100;
      player.points = 0;
    });
  }

  ///@abi action
  void update(const name account, uint64_t level, uint64_t health, uint64_t points){

    require_auth(account);
    playerIndex players(_self,_self);
    auto iterator = players.find(account);
    eosio_assert(iterator != players.end(), "Address of account does not exists")

    players.modify(iterator, account, [&] (auto& player){

      player.level = level;
      player.points += points;

      if((player.health - health) < 0){
        player.health = 0;
      }else{
        player.health -= health;
      }
    });

  }

  ///@abi action
  void getplayer(const name account){

    playerIndex players(_self,_self.value);
    auto iterator = player.find(account);
    eosio_assert(iterator != players.end(), "Address of account does not exists")

    auto currentPlayer = players.get(account);
    print("username : ", currentPlayer.username.c_str(), "level : ", currentPlayer.level, "helth : ", currentPlayer.health, "points : ", currentPlayer.points);

  }


  private:

  ///@abi table player uint64
  struct player {
    uint64_t account_name;
    string username;
    uint64_t level = 1;
    uint64_t health = 100;
    uint64_t points = 0;

     uint64_t primary_key() const {return account_name;}

    EOSLIB_SERIALIZE(player, (account_name)(username)(level)(health)(points))

  };    

  typedef multi_index<N(player), player> playerIndex;

}

EOSIO_DISPATCH(mygame, (add)(update)(getplayer))

below are the errors shown

/project/src/mygame.cpp:84:25: error: 'player' does not refer to a value
  typedef multi_index<N(player), player> playerIndex;
                        ^
/project/src/mygame.cpp:71:10: note: declared here
  struct player {
         ^
/project/src/mygame.cpp:18:17: error: excess elements in scalar initializer
    playerIndex players(_self,_self);
                ^            ~~~~~~
/project/src/mygame.cpp:37:17: error: excess elements in scalar initializer
    playerIndex players(_self,_self);
                ^            ~~~~~~
/project/src/mygame.cpp:58:17: error: excess elements in scalar initializer
    playerIndex players(_self,_self.value);
                ^            ~~~~~~~~~~~~
/project/src/mygame.cpp:59:21: error: 'player' does not refer to a value
    auto iterator = player.find(account);
                    ^
/project/src/mygame.cpp:71:10: note: declared here
  struct player {
         ^
/project/src/mygame.cpp:63:26: error: use of undeclared identifier 'currentPlayer'
    print("username : ", currentPlayer.username.c_str(), "level : ", currentPlayer.level, "helth : ", currentPlayer.health, "points : ", currentPlayer.points);
                         ^
/project/src/mygame.cpp:63:70: error: use of undeclared identifier 'currentPlayer'
    print("username : ", currentPlayer.username.c_str(), "level : ", currentPlayer.level, "helth : ", currentPlayer.health, "points : ", currentPlayer.points);
                                                                     ^
/project/src/mygame.cpp:63:103: error: use of undeclared identifier 'currentPlayer'
    print("username : ", currentPlayer.username.c_str(), "level : ", currentPlayer.level, "helth : ", currentPlayer.health, "points : ", currentPlayer.points);
                                                                                                      ^
/project/src/mygame.cpp:63:138: error: use of undeclared identifier 'currentPlayer'
    print("username : ", currentPlayer.username.c_str(), "level : ", currentPlayer.level, "helth : ", currentPlayer.health, "points : ", currentPlayer.points);
                                                                                                                                         ^
/project/src/mygame.cpp:88:1: error: expected unqualified-id
EOSIO_DISPATCH(mygame, (add)(update)(getplayer))
^
/usr/opt/eosio.cdt/1.6.1/bin/../include/eosiolib/dispatcher.hpp:115:8: note: expanded from macro 'EOSIO_DISPATCH'
extern "C" { \
       ^
10 errors generated.
Error while processing /project/src/mygame.cpp.
abigen error
Warning, empty ricardian clause file
Warning, empty ricardian clause file

This is the reference to the video tutorial

https://www.youtube.com/watch?v=cfbZfdGsGAE&list=PLL5pYVd8AWtSW4lHcWplRP6rTybxxj3yu&index=12

Answer 1

Probably the Version of eosio.cdt used by eossstudio is a lot more recent version than the one used in the video.

Try to use

C++11 Style Attributes

instead of the old notation-scheme.

Try to change the following:

class mygame : public contract { to class [[eosio::contract]] mygame : public contract {

all ///@abi action to [[eosio::action]]

and ///@abi table player uint64 to struct [[eosio::table]] player{

add a ; after the last curly braket

You should follow the available and recent tutotials on developers.eos.io for a basic understanding about these notations. Don't use Video-tutorials older than half a year.

Answer 2

I tried to code something that I think it could help. In my implementation I don't use EOS studio but I manage to build my contract and put it on my local EOS blockchain. I am using two files: game.cpp and game.hpp.

//game.hpp
#include <eosio/eosio.hpp>

using namespace std;
using namespace eosio;

CONTRACT game : public contract {

  private:

    struct [[eosio::table]] player {
        name account;               // player account - primary key
        std::string username;       // player username
        uint64_t level;             // player level
        uint64_t health;            // player health
        uint64_t points;            // player points

        uint64_t primary_key() const { return account.value; }
    };
    typedef multi_index<name("players"), player> players_table;

  public:

    game( name receiver, name code,
      datastream<const char*> ds ) :
      contract(receiver, code, ds)
      {}

      ACTION add(
        name account,
        std::string username,
        uint64_t level,
        uint64_t health,
        uint64_t points,
    );
};


//game.cpp
#include "game.hpp"

ACTION game::add(
    name account,
    std::string username,
    uint64_t level,
    uint64_t health,
    uint64_t points) {

  require_auth(account);

  players_table players( get_self(), get_first_receiver().value );

  auto player_iterator = players.find(account.value);
  if (player_iterator == players.end()) {
    players.emplace(account, [&]( auto& row ) {

        row.account = account;
        row.username = username;
        row.level = level;
        row.health = health;
        row.points = points;

    });

  }
}

EOSIO_DISPATCH(game, (add))