EOSIO smart contract development with EOSFactory framework - Tutorial 2

What Will I Learn?

EOSIO - Tutorial 2
EOSIO smart contract development with EOSFactory framework

Setup for smart contract development on Linux OS (should work on Windows and Mac)

• You will learn how to setup EOSIO with EOSFactory for smart contract development
• You will learn how to install and build
• You will learn how to test EOSFactory
• You will learn how to generate contract from template
• You will learn how to script, build and simulate contracts

Repository

https://github.com/blws/eos-devenv

Requirements

• Linux OS (should work on Windows and Mac)

• 4 GB RAM

• visual studio code

• basic python knowladge

• basic C++ knowladge

• basic EOSIO knowladge you can find my last tutorial here

• installed clang-4-0 lldb-4.0

sudo apt-get install clang-4.0 lldb-4.0
sudo update-alternatives --install /usr/bin/clang clang /usr/bin/clang-4.0 40 --slave /usr/bin/clang++ clang++ /usr/bin/clang++-4.0
sudo apt-get install clang-4.0 clang++-4.0
update cmake

https://askubuntu.com/questions/859256/how-to-install-gcc-7-or-clang-4-0

• installed python3-pip
• installed termcolor

sudo apt install python3-pip
python3 -m pip install termcolor

• visual studio code
• plugins for studio code:
  • C/C++ IntelliSense, debugging and code browsing.
  • CMake Tools
  • Python

Difficulty

• Basic

Tutorial Contents

This repository is an enviroment to script, build and develop eos smart contracts.

Project structure

I'm using eos and eosfactory submodules forked from https://github.com/tokenika

Clone

Clone repository like this

git clone https://github.com/blws/eos-devenv --recursive

Install and build

After download

cd eos-devenv
sudo ./install.sh

or manually install

cd eos
./eosio_build.sh
cd build
sudo make install
cd ../..

cd eosfactory
./build.sh ~/your_install_path/eos ~/your_install_path/contracts
source ~/.profile

Test EOSFactory

To make sure everything works test EOSFactory

cd eosfactory
source ~/.profile
python3 ./tests/unittest1.py
python3 ./tests/unittest2.py
python3 ./tests/unittest3.py
cd ..

Generate contract from template

Templates are located in eosfactory/templates

You can find templates https://github.com/blws/eosfactory/tree/master/templates/contracts
or you can make your own.

To generate contracts change directory to eos-devenv/contracts, then

source ~/.profile
python3 generate.py -name -template

It generates skeleton template if no template

Examples

cd contracts
python3 generate.py example1
python3 generate.py example2 hello
python3 generate.py example3 eosio.token

Build and Script

Visual Studio Code setup and extensions

Open contracts/hello.author folder with visual studio code.

First time you open select clang 4

Enable IntelliSense

Install extensions

Hello world example

Open contracts/hello.author

Open src/hello.author.cpp

#include <eosiolib/eosio.hpp>

//how to include logger
#include "logger.hpp"

using namespace eosio;

class hello : public eosio::contract {
  public:
      using contract::contract;

      /// @abi action 
      void hi( account_name user ) {
         logger_info( "user: ", name{user} );
      // how to requre auth
         require_auth( user );
         
         print( "Hello, ", name{user} );
      }
};

EOSIO_ABI( hello, (hi) )

This is just modified hello contract with 3 added lines: include, log, require_auth

This shows how to log and requrie authentication.

Take a look at hello.author/script.py before we build contract

#import everything you need
import node
import sess
import eosf

#resets and starts testnet
node.reset()

#deploys eosio.bios and creates
#sess.eosio sess.alice sess.bob sess.carol
sess.init()

#create account
john = eosf.account(sess.eosio, name="john")
sess.wallet.import_key(john)

#sets conctract
contract = eosf.Contract(john, "hello.author")

#builds
contract.build()

#hash before deploy
contract.code()

#deploys
contract.deploy()

#hash after deploy
contract.code()

#Will not work
#contract.push_action("hi", '{"user":"' + str(sess.carol) + '"}', sess.alice, output=True)

#Will work 
contract.push_action("hi", '{"user":"' + str(sess.carol) + '"}', sess.carol, output=True)

node.stop()

Code is pretty self explanitory.

User has to be authencticated to recive hello message.

To run script first set

source ~/.profile

Run

python3 script.py

To run without exit comment out node.stop() and

python3 -i script.py

press Ctrl + D to exit

eosio token example

This example shows how to create issue and transfer tokens

Open contracts/eosio.token folder with visual studio code.
Open contracts/eosio.token/script.py

#create users
#load bios.contract and eosio.token contract
#deploy
###############################################
import node
import sess
import eosf
import cleos

node.reset()
sess.init()

bpaccount = eosf.account(sess.eosio, name="bpaccount")
sess.wallet.import_key(bpaccount)

john = eosf.account(sess.eosio, name="john")
sess.wallet.import_key(john)

adam = eosf.account(sess.eosio, name="adam")
sess.wallet.import_key(adam)

#Error 3060003: Contract Table Query Exception -> if wrong name
contract = eosf.Contract(bpaccount, "eosio.token")
contract.build()
contract.code()
contract.deploy()
contract.code()

contract.push_action("create", '{"issuer":"' + str(sess.eosio) + '", "maximum_supply":"1000000000.0000 EOS", "can_freeze":0, "can_recall":0, "can_whitelist":0}')

contract.push_action("issue", '{"to":"' + str(bpaccount) + '", "quantity":"100.0000 EOS", "memo":"memo"}', sess.eosio)

contract.push_action("transfer", '{"from":"' + str(bpaccount) + '", "to":"' + str(john) + '", "quantity":"25.0000 EOS", "memo":"memo"}', bpaccount)

contract.push_action("transfer", '{"from":"' + str(bpaccount) + '", "to":"' + str(adam) + '", "quantity":"25.0000 EOS", "memo":"memo"}', bpaccount)

keyarray = cleos.WalletKeys(is_verbose=0).json['']

unqnamearray = []

for key in keyarray:
    namearray = cleos.GetAccounts(key,is_verbose=0).json["account_names"]
    for name in namearray:
        if name not in unqnamearray:
            unqnamearray.append(name)

for name in unqnamearray:
    print(name)
    contract.table("accounts", name)

node.stop()

After we push all actions

keyarray = cleos.WalletKeys(is_verbose=0).json['']

cleos.WalletKeys() returns array of public keys (6 accounts owner and active plus default)

unqnamearray -> all accounts

for name in unqnamearray:
    print(name)
    contract.table("accounts", name)

Last for loop prints all accounts and balances

adam
{
  "rows": [{
      "balance": "25.0000 EOS"
    }
  ],
  "more": false
}


carol
{
  "rows": [],
  "more": false
}


alice
{
  "rows": [],
  "more": false
}


bpaccount
{
  "rows": [{
      "balance": "50.0000 EOS"
    }
  ],
  "more": false
}


john
{
  "rows": [{
      "balance": "25.0000 EOS"
    }
  ],
  "more": false
}


bob
{
  "rows": [],
  "more": false
}

Useful links:

http://eosfactory.io/sphinx/build/html/

Curriculum

Tutorial 1

This is Tutorial 2

Proof of Work Done

https://github.com/blws/eos-devenv/commits/master
https://github.com/blws/eosfactory/tree/36721be4eb693dfa0eda757dab85ab8e799aa6fc
https://github.com/blws/eos/tree/2a4ffd7ae89dc4f184537b88cf3e905162de93f3
https://github.com/blws/eos-devenv/blob/master/install.sh
https://github.com/blws/eos-devenv/blob/master/contracts/generate.py
https://github.com/blws/eos-devenv/tree/master/contracts/hello.world
https://github.com/blws/eos-devenv/tree/master/contracts/hello.author
https://github.com/blws/eos-devenv/tree/master/contracts/eosio.token