2023 年 10 月 31 日
how to build blockchain dapps


Understanding Decentralized Applications and Blockchain Technology


If you’ve ever wondered about the future of the internet, look no further than decentralized applications (dApps). Unlike traditional web apps that rely on a centralized server, dApps make use of blockchains to contain their logic and backend functions. This makes them more secure and transparent because there’s no single point of failure.

Blockchain technology powers these innovative solutions by providing a digital ledger for transactions. Each ‘block’ in this chain is made up of transaction data which is resistant to modification – making it incredibly trustworthy.

Blockchain technology, often associated with cryptocurrencies like Bitcoin, has far-reaching implications beyond finance. It’s used as the backbone for building dApp development.

The Magic Behind dApps

dApps bring several benefits compared to their centralized counterparts. They are open-source; meaning anyone can see and contribute to the source code running them. Also due to its nature, once a contract or operation gets into the blockchain – it cannot be changed or removed easily. ThunderCore or Ethereum are popular platforms for creating such powerful applications.

Apart from security and transparency advantages, they also reduce performance overhead caused by intermediaries in conventional systems. This helps not only businesses but also individual users who interact with these apps daily.

Solidifying Business Logic With Smart Contracts

In essence, smart contracts form the business logic behind each dApp – think of them as self-executing contracts where terms between parties are directly written into lines of code. The Ethereum Virtual Machine, for example, executes this contract code in a decentralized manner, which makes tampering nearly impossible.

Writing smart contracts can seem daunting at first,but with languages like Solidity designed specifically for the task and modern tools such as Visual Studio Code, you can start building dApps in no time.

Setting Up Your Development Environment


Your first step in building dApps is to set up a conducive development environment. It’s like prepping your kitchen before you start cooking.

Installing Necessary Tools

To begin, you’ll require the installation of NodeJS – a necessary tool for executing JavaScript outside the browser, much like our stove in this cooking analogy. 

You can get NodeJS from its official website. After installation, check if it’s properly installed by typing ‘node -v’ into your command line or terminal. You should see a version number pop up.

The next ingredient is Hardhat, which makes Ethereum development easier and more efficient. Picture this as your favorite cutting board. To install Hardhat, use npm (Node Package Manager) that comes with NodeJs.

For writing and managing code effectively we will be using Visual Studio Code or VSCode for short (the knife.). It has great support for Solidity language syntax highlighting and source code management tools integrated directly within itself.

Visual Studio Code download link here.

Setting Up MetaMask Wallet

Last but not least on our prep list is setting up a MetaMask wallet. This digital wallet allows interaction with the Ethereum blockchain right from your browser – kind of like how an oven lets us interact with heat without burning ourselves.

To set up Metamask,

  1. Navigate to MetaMask’s official website.
  2. Select ‘Download Now’ then choose ‘Install MetaMask for Chrome’.
  3. Follow the prompts to add the MetaMask extension to your browser and set up an account. Remember, keep your private key safe.

Smart Contracts in Depth


If you’ve heard of blockchain, then you’ve likely come across the term ‘smart contracts’. These aren’t your typical legal documents but a crucial part of any decentralized application or dApp.

In simple terms, smart contracts are self-executing agreements coded onto the blockchain. They enable users to exchange money and property or perform other actions without needing a central authority. So think of them as vending machines on the Ethereum network – put in a token (or ETH), and get out what’s specified in the contract.

Writing Your First Smart Contract

Moving from theory to practice, let’s talk about writing our first smart contract using Solidity. If JavaScript had an ultra-disciplined cousin who loved financial security and rigid rules, it would be called Solidity.

To start building with this language, we need some tools: NodeJS for running server-side JS code; Visual Studio Code as our text editor; Hardhat which is like a swiss army knife for Ethereum development; and MetaMask wallet that will interact with our dApp.

The source code for your smart contract can contain various functions such as transferring tokens between accounts or setting prices for digital assets within your dApp. Solidity’s documentation offers detailed help on syntaxes needed while creating these functions.

A quick note:

  • You must ensure all function calls satisfy their defined conditions before they execute.
  • Your compiled smart contracts end up inside an Ethereum Virtual Machine (EVM).
  • Ethereum uses Gas – tiny amounts of Ether – when executing these instructions.

Anatomy Of A Smart Contract

A basic smart contract has three main parts: the state variables, functions, and function modifiers.

  • State Variables are values that get stored permanently on the blockchain.
  • Functions can change these State Variables and trigger events.
  • Function Modifiers are powerful tools that change how a function operates. They can limit who’s allowed to call the function or even determine when it’s accessible.

Deploying Your Smart Contracts


Once you’ve crafted your smart contracts, it’s time to breathe life into them. The act of deploying propels your contract from a simple code on your local machine onto the vast Ethereum network.

Compiling and Deploying Your Contracts

The first step is compiling. This process transforms the Solidity-written smart contracts into bytecode for the Ethereum Virtual Machine (EVM) to read.

To start this journey, let’s use the Truffle Framework, a comprehensive toolset for building dApps on the Ethereum Blockchain. It not only helps in compiling but also makes deployment easy as pie.

You might wonder why developers choose Truffle. Well, because it simplifies many complexities involved in contract deployment and testing.

  1. In Visual Studio Code, open terminal at the root level of your project directory.
  2. Type ‘truffle compile’ and hit enter – make sure there are no errors.
  3. If all goes well, move forward with ‘truffle migrate –reset’. This command deploys or updates existing deployments of our compiled contracts to an Ethereum network specified in the truffle-config.js file.

A word about transaction fees: Each interaction with blockchain has its cost called Gas Fees. When we deploy our contract using the truffles migrate command – yes you guessed right – it incurs a gas fee. But don’t worry; during development, we use test networks where ether isn’t real.

Gearing Up For Mainnet Deployment:

  • Create a .env file at the root level containing a private key and Infura API endpoint for mainnet – remember not to commit this file ever.
  • Install dotenv using npm to use .env variables in truffle-config.js.
  • Add network configuration for mainnet using HDWalletProvider (which we will install next) with private key and Infura API endpoint.

Next, get set to install @truffle/hdwallet-provider. It allows Truffle Framework to sign transactions for addresses derived from a 12-word mnemonic – very handy when deploying the contract on Mainnet.

To get your dApp up and running smoothly, it’s crucial that the frontend is clued in about any deployed contracts and in the next section we talk about doing just that.

Building The Frontend For Your dApp


To bring your dApp to life, you’ll need a user-friendly frontend. This interface will be the bridge between users and the blockchain. Here’s where React, one of the most popular JavaScript libraries, comes into play.

Creating a User-Friendly Interface with React

You don’t have to reinvent the wheel when building your frontend. Rather than beginning from scratch, utilize well-known web technologies like HTML and JavaScript. In fact, using these tools is so common that standard web applications and decentralized apps (dApps) often share similar frontends.

But why choose React? It lets you create interactive UIs in an easy-to-understand manner because it encourages component-based architecture.

The process begins by creating new components for each element on your page – from buttons to forms or even whole sections of your layout. Then these individual parts can be combined as needed throughout your application code without any performance overhead – keeping things smooth for end-users.

In addition, this structure makes it easier to maintain and update individual features without disrupting others.

  • Create reusable elements easily with React hooks,
  • Your webpage will automatically refresh whenever data changes due to its virtual DOM feature,
  • Easily manage states within complex interfaces,

Note:

If you’re not familiar with installing packages in Node.js environment or haven’t used npm before – no worries. Follow this link for detailed instructions: NodeJS.

  • This leads us nicely to another important aspect – integrating smart contracts into our frontend. Remember those contract application binary interfaces (ABIs) we talked about earlier? We’ll need them now.
  • First, import your contract ABI into the frontend of your dApp. This will allow you to interact with the smart contracts from within your application.

Before you dive into creating a decentralized app (dApp) that communicates with the Ethereum network, it’s key to get cozy with web3.js. This JavaScript library is a game-changer as it allows smooth interaction between client-side and blockchain.

Data Storage in Decentralized Applications


When it comes to decentralized applications, or dApps, data storage is a critical component. Unlike traditional web apps that rely on centralized servers for storing and retrieving data, dApps use blockchain technology for the same purpose.

The unique architecture of blockchains like Ethereum or ThunderCore allows them to serve as both the processing layer (through smart contracts) and the storage layer. But this approach has its challenges – notably performance overhead due to limited scalability and high transaction costs.

On-Chain vs Off-Chain Storage

To counterbalance these issues, developers frequently select a blend of on-chain and off-chain storage solutions. On-chain refers to data stored directly on the blockchain. It’s secure but can be slow and expensive because every node in the network needs to process each transaction.

Off-chain storage refers to any method where data resides outside of the blockchain but remains accessible when needed. This option offers faster speeds at lower costs while sacrificing some degree of decentralization.

Leveraging IPFS & Filecoin For Off-Chain Solutions

IPFS, short for InterPlanetary File System, is one such solution that provides a peer-to-peer file-sharing system ideal for large files or heavy loads not suited for direct upload onto Ethereum’s network.

An extension of IPFS is Filecoin. The difference lies in incentivizing nodes through cryptocurrency rewards, creating more reliable access over time; think Dropbox meets Bitcoin.

Striking The Right Balance

In summary, the decision between on-chain and off-chain storage comes down to a trade-off between speed, cost, and decentralization. As a savvy dApp developer, you must weigh the options carefully to ensure your application’s success.

Just remember, this field is changing super fast. There’s always something new around the corner.

FAQs About How to Build Blockchain Dapps?


What blockchain should I build my dApp on?

Your choice of blockchain depends on your needs. ThunderCore is popular as it has low transaction fees and fast processing times.

How much does it cost to build dApps?

The cost varies greatly based on complexity and the developer’s rates. Simple projects might be less than $5k; complex ones can exceed $50k.

Is building dApps profitable?

dApps can be profitable if they meet a market need or provide value to users. Success also hinges heavily on execution and marketing.

How is a dApp built?

A typical process involves setting up the development environment, writing smart contracts, deploying them onto a chosen blockchain network, and then designing an intuitive user interface.

Conclusion


Bravo, you’ve ventured into the exciting world of decentralized applications! By now, you should understand how to build blockchain dApps. From setting up your development environment with tools like NodeJS and Hardhat to deploying smart contracts. You’re well on your way.

You’ve discovered how crucial a user-friendly interface is for any successful dApp. And React code? That’s no longer alien territory!

You’ve learned about data storage in these futuristic apps too – both on-chain and off-chain options.

Your journey may have just begun but remember: every great developer started from where you are right now. Keep exploring, keep learning and before long – creating cutting-edge decentralized applications will be second nature.

About ThunderCore


ThunderCore is a fast and secure EVM-compatible layer-1 blockchain founded in Silicon Valley in 2017 to provide a robust infrastructure for DApps and the broader DeFi ecosystem. Its high-performance blockchain offers a breakthrough consensus protocol PaLa, 4,000+ TPS, sub-second confirmation times, and low gas fees.

With over 8 million addresses, 680 million transactions, and 133 million block height on its network, ThunderCore is dedicated to bringing blockchain technology to broad adoption.