morokoff

Eos.io

via Training.eos.io Platform

06.02.2020

Online Educational Course “Smart Contracts 201”

The content of the modules:

Module 1: Assets

• Introduction to tokens
• The eosio.token contract
• The asset type

Module 2: Receiving Transfers

• on_notify, especially [[eosio::on_notify(“eosio.token::transfer”)]]
• The old way: custom apply()

Module 3: In-line Actions

• Review of the eosio.code permission
• require_recipient()
• Explanation of why we must use require_auth(get_self()) with require_recipient()
• <action type>.send(…), the action constructor (permission, action, data)
• Action wrappers
• Custom permissions

Module 4: Singletons

• Appropriate for single-row use cases, such as contract settings
• Using get() and set()

Module 5: Bonus Lab: Add a “Pot”  to Tic Tac Toe Games

Module 6: Updating Table Schemas and Migrating Data

• Review of inability to update structure of contract table containing data
• Description of migration options, including the binary_extension wrapper

Module 7: Getting Data from the Outside World

• The Oracle Problem
• Potential exploits (frontrunning, collusion, etc.)
• Delphi
• Provable
• Native EOSIO Oracles
• LiquidOracles

Module 8: Organizing Action Parameters

• Action parameter list organization and serializiation
• Situations requiring packed parameters

Module 9: Randomness

• Recap of the need for determinism in blockchains
• Pseudo-randomness and its dangers
• Multi-party randomness
• Oracle-based randomness

Module 10: Scheduled and Recurring Actions

• Deprecated: deferred transactions
• Provable, LiquidOracles, and other methods for scheduling actions
• Using contract design to mitigate the need for scheduled actions

Module 11: User-Friendly Resource Management

• RAM Payer
• ONLY_BILL_FIRST_AUTHORIZER

Module 12: More to Explore: Interoperability and Testing Frameworks

• Intro to interoperability/IBC
• Survey of testing tools available for EOSIO smart contracts