basics.md

Creating your first Smart Contract

1) Changing some settings to listen on all interfaces

• sudo nano ~/.local/share/eosio/nodeos/config/config.ini
• Change the http-server-address to 0.0.0.0:8888
• sudo nano ~/.bash_aliases
• Add a # in front of the cleos alias we set up before, we will no longer use it
• restart nodeos

2) Setting up the comptract.sh script

• cd ~
• mkdir scripts
• cd scripts
• nano comptract.sh

#!/bin/bash

if [[ $# -ne 2 ]]; then
    echo "USAGE: comptract.sh <ACCOUNT NAME> <Contract Name> from within the directory"
    exit 1
fi

ACCOUNT=$1
CONTRACT=$2

eosiocpp -o ${CONTRACT}.wast ${CONTRACT}.cpp && 
eosiocpp -g ${CONTRACT}.abi ${CONTRACT}.cpp && 
cleos set contract ${ACCOUNT} ../${CONTRACT}

• chmod +x comptract.sh
• Add export PATH=$PATH:~/scripts to the end of your ~/.profile file
• export PATH=$PATH:~/scripts

3) Create a new account for the basics contract

• cleos create account eosio basics <PUBLIC KEY> <PUBLIC KEY>

4) Creating the basics contract

• Make a new directory inside of your shared_contracts folder called tutorials and then another inside of that called basics
• Create a new cpp file called basics.cpp

#include <eosiolib/eosio.hpp>
#include <eosiolib/print.hpp>

using namespace eosio;
using namespace std;

class basics : public contract {
    using contract::contract;

    public:
        basics( account_name self ) :
            contract(self),
            _statuses(_self, _self){}

        // @abi action
        void test( name sender, string status ){
            require_auth(sender);

            auto iter = _statuses.find(sender);
            if(iter == _statuses.end()) _statuses.emplace( sender, [&]( auto& row) {
                row.sender = sender;
                row.status = status;
            });
            else _statuses.modify( iter, 0, [&]( auto& row) {
               row.status = status;
            });
        }

    private:

        // @abi table
        struct statuses {
            name sender;
            string status;

            name primary_key() const { return sender; }
            EOSLIB_SERIALIZE( statuses, (sender)(status) )
        };

        multi_index<N(statuses), statuses> _statuses;


};

EOSIO_ABI( basics, (test) )

5) Compiling and testing

• cd /media/sf_shared_contracts/tutorials/basics/
• comptract.sh basics basics
• cleos push action basics test '["asdf"]' -p eosio
• cleos push action basics test '["eosio", "Hello World"]' -p eosio