HPB Dapps

First of all, Dapp is a service which originally runs on ETH. Now most public chains, including HPB, are compatible with this service. DAPP enables direct interaction between end-users and providers (for instance, connecting buyers and sellers in markets, as well as asset owners and stores in file storage). HPB Dapps typically use Javascript API to interact with users via an HTML/Javascript Web application, so as to communicate with the whole HPB blockchain. HPB Dapps typically have their own set of related contracts on the blockchain to encode business logic and allow persistent storage of its critical consensus state. Keep in mind that due to the computational redundancy on the HPB network, the cost of performing GAS is always higher than when it is performed on a private execution chain. This motivates dapp developers to limit the amount of lines of code they execute and the amount of data they store on the blockchain.

The distributed services offered cover a wide range of industries, including finance, insurance, forecasting markets, social networking, distributed computing and storage, gambling, marketing, internet of things, governance, collaboration, development and gaming.

In the future, dapps may be distributed in dapps stores in a dapp browser.

Developer’s Toolkit

Dapp development requires knowledge of such programming languages as Web3 Javascript API, JSON RPC and Solidity.

Note

The following developing tools might come in handy.

• Web3 JavaScript API - JavaScript SDK, used to connect HPB nodes.
• JSON RPC API - API for JSON RPC 2.0, used to interact with HPB nodes. This API is primarily designed for Web3 JavaScript API.
• HPB Web3j Java SDK
• Solidity Docs - Solidity is a smart contract language developed by Ethereum to compile codes into EVM (Ethereum Virtual Machine) opcodes.
• Solium - Strictly comply with Solidity as defined by the official Solidity Style Guide.
• HPB Test Network - The test network helps developers develop and test HPB codes and network interactions without having to use their own HPB tokens on the primary network. The HPB test network is temporarily out of service, so stay tuned.
• Dapp developing resources. This helps you develop, debug and deploy Ethereum applications.

Dapp Developing Resources

• Smart contracts ELI5
• https://blog.slock.it/a-primer-to-the-decentralized-autonomous-organization-dao-69fb125bd3cd
• A 101 noob’s intro to programming smart contracts
• Standardised contract APIs listing

Common Examples

• example use of pricefeed - web3 script printing all account balances
• Example Ethereum contracts
• https://dappsforbeginners.wordpress.com/tutorials/your-first-dapp/
• https://github.com/ethereum/wiki/wiki/Dapp-Developer-Resources

Tutorial

• ETH Dapp Universal Tutorial
• Beginners’ Guide to Dapps
• Eris’ Solidity Tutorial Series
• Advanced Course of Solidity
• http://ethereumj.io/blog/2015/09/09/friendly-ether-bot/
• https://github.com/ConsenSys/ether-pudding

MIX-IDE

Mix is the official Ethereum IDE and has also been used for HPB's dapp development. It allows developers to build and deploy contracts and distributed applications on HPB blockchain. It includes the IDE/Framework for the Solidity Source Code Debugger.

Below are some commonly used development frameworks and IDEs for dapps development.

• Truffle -Ethereum's development environment, test framework and asset pipeline.

• Dapple - a tool which helps Solidity developers build and manage complex contract systems like Ethereum blockchain

• Populus -a smart contract development framework written in python

• Eris-PM - For Eris Package Manager to deploy and test smart contract systems on private and public chains.

• Embark - a Ðapp development framework written in JavaScript.