bubble501 / advanced-eos-examples

A collection of EOS contract examples

EOS Examples

This repository contains a collection of Advanced EOS concepts and examples.

Examples

Topics covered

• Cryptography
• Singletons
• Multi-Index Tables
• Contract-to-Contract Communication
• Delayed Transactions

Getting Started

Setting up a local environment

Before we can run any examples, we need somewhere to deploy them. Let's setup a local EOS block producer to deploy and test our contracts.

Clone EOS recursively from the GitHub Repository.

git clone https://github.com/EOSIO/eos.git --recursive

Enter the eos directory and build.

cd eos
./eosio_build.sh

Start a clean nodeos server locally. The --delete-all-blocks flag will clear any existing blocks and accounts.

nodeos -e -p eosio --plugin eosio::chain_api_plugin --plugin eosio::history_api_plugin --delete-all-blocks

Creating deployment accounts

If your starting fresh, you'll need to create a wallet. Open another terminal and run the command

cleos wallet create

Remember to make a copy of the password/keys printed to the terminal

Let's also create a new public/private key pair for our new wallet.

cleos wallet create_key

We can now use this public key for our new accounts. Replacing the ACTIVE_PUBLIC_KEY and OWNER_PUBLIC_KEY with the public key we just created.

cleos create account eosio example.singletons OWNER PUBLIC_KEY ACTIVE_PUBLIC_KEY

Now our example.singletons account is ready for our contract code.

Cheat Sheet

Each individual example will cover how to build, deploy and interact with the contract. But as a reference, the general commands we will be using are listed below.

Building WebAssembly & Application binaries

Before contracts can be deployed to the blockchain, they first need to be compiled to WebAssembly. We will use the provided eosiocpp -o [wasm-file] [source-file] command to generate our Web Assembly file.

eosiocpp -o ./singletons.wast singletons.cpp

Interacting with our contract requires an application binary interface. This can be created with the command eosiocpp -g [abi-file] [source-file] like so;

eosiocpp -g ./singletons.abi singletons.hpp

Deploying Contracts

To publish our contract on the blockchain, we can use the command cleos set contract [account] [wasm-file] [abi-file], with our newly created account, webassembly file and abi.

cleos set contract example.singletons ./singletons.wasm ./singletons.abi

Interacting with Contracts

Finally interacting can be done with cleos push action [account-code] [action-name] '[data-object]' -p [permission] like so;

cleos push action example.singletons add '["mitch"]' -p mitch