Soroban Snippets: Guide to Soroban Smart Contracts for Web3 DApps
Tags: soroban, stellar, javascript, web3
Published: 2023-12-01 05:00:00

# 1. Installing Contract/WASM to Soroban

One of the first things to do when needing to deploy a Soroban contract is to deploy its `.wasm` file on the Soroban blockchain. The following tutorial guides developers through essential steps for ensuring their smart contracts are deployment-ready on Soroban. Notably, it distinguishes between installing and deploying a smart contract, shedding light on the former. The document introduces the use `soroban-client` tool and delves into the critical role of `hostFunctionTypeUploadContractWasm` in JavaScript. Practical usage is demonstrated through code snippets, explaining the interaction with the Soroban blockchain, transaction building, and signing process with **Freighter**. Overall, it stands as a valuable resource for developers navigating the intricacies of smart contract installation on the Soroban blockchain in a web environment.

[Installing Contract/WASM to Soroban](https://soroban-snippet.vercel.app/?title=79c9750ceb633dc23e58617e71a88761650cebee00383b9237adefec3c6debe0)

# 2. Soroban Contract Deployment

Having successfully deployed a contract WASM on Soroban, the next step involves creating a contract instance. This tutorial explores the deployment process, emphasizing the utilization of the `soroban-client` js library to contract deployment on Soroban. It focuses on key elements such as the creation of a **contract ID preimage** and the construction of contract arguments. The guides will help web3 developers through the process of building a host function transaction. To enhance practical understanding there is also a working demo allowing users to interactively deploy a **Soroban token**, equipping developers with the knowledge and tools required for proficient Soroban smart contract deployment in JavaScript and TypeScript.

[Soroban Contract Deployment](https://soroban-snippet.vercel.app/?title=be958880d0b612c39ab42b2dce78173f645c908449fe4eedbd744cd388eddfa3)

# 3. Execute Soroban Smart Contract

There are several approaches to invoking methods of a Soroban contract, and this demonstration introduces the capabilities of the `Contract` class in the `soroban-client` library. With interactive examples, it provides insights into seamless communication with smart contracts. Similar to the token contract discussed in Part 2, we'll implement a TypeScript code snippet that demonstrates the invocation process and transaction building using the `contract.call()` method for Soroban. This guide aims to showcase the practical application of the `Contract` class, enabling developers to effectively interact with and execute transactions on Soroban smart contracts.

[Execute Soroban Smart Contract](https://soroban-snippet.vercel.app/?title=8caa307d786a1afcf370be5a8f037f637bccefe46e012584ef0374ca69636c2f)

# 4. Retrieve WebAssembly (WASM) Code from Smart Contract

You can do many things in your web application with the `soroban-client`. One of which is retrieving the WebAssembly (Wasm) code from a Soroban contract. Beyond gaining insights into the contract, its modules, and imports/exports, developers can leverage this feature for deploying an identical contract to Soroban without the need for recompilation or for inspecting the contract code. The **contractData** and **contractCode** steps outline a streamlined two-step procedure for obtaining the Wasm file associated with a Soroban smart contract. This entails querying the Soroban blockchain to retrieve the **Wasm ID** and subsequently using that ID to fetch the corresponding Wasm file. Soroban Snippet introduces a comprehensive function, elucidated in the code below, that facilitates the retrieval of the Wasm file from the blockchain as a **downloadable file**, providing developers with a powerful tool for a deeper understanding of Soroban contract intricacies.

[Retrieve WebAssembly (WASM) Code from Smart Contract](https://soroban-snippet.vercel.app/?title=2fc6a1c736f314c52393754b6e74ebccce0a973847768c2a1e75f045f4a886bd)

# 5. Access Soroban Contract Storage State

In addition, Soroban has many storage types to avoid storage bloats and manage efficiency data on the chain. The provided tutorial will focus on the **storage state** and information of a Soroban smart contract, this guide sheds light on the key-value pairs stored within the contract. Specifically, it delves into the `Instance` storage, accessible through the `Env.storage().instance()` code in your Dapps. Subsequently, we again introduce again to `contractData` in the `soroban-client` JS library. This step involves constructing a `LedgerKey` for contract data, fetching **ledger entries** from the Soroban server, and extracting relevant information, such as instance storage. Of course, every tutorial will provide a snippet and runnable example to see what you can expect when using these methods.

[Access Soroban Contract Storage State](https://soroban-snippet.vercel.app/?title=88834785d0f3929a0efbd5220ebd7b7a9c39a0434186455ea70607670d1b249a)

# 6. Construct Soroban Contract ABI in JavaScript/TypeScript

If you ever find yourself needing to explore a Soroban contract's methods along with their inputs and outputs, the Soroban CLI comes with its `inspect` command. This command, when provided with the WebAssembly (Wasm) code, returns a detailed list of contract specifications. These specifications include functions, as well as custom data types like enums and structs, associated with the Rust code. However, when working on a web app, integrating this process might pose some challenges. Therefore, this tutorial endeavours to establish an approach for obtaining comprehensive insights into a Soroban contract that goes beyond just its Wasm code. The goal is to create a method that emulates the functionality of the `inspect` command. It's worth noting that this involves utilizing the `WebAssembly.Module` inherent to JavaScript and the Soroban convention for storing information in the `contractspecv0` section.

[Construct Soroban Contract ABI in JavaScript/TypeScript](https://soroban-snippet.vercel.app/?title=cea23fe9629b45b45de50c6d586e570d0d823d1a0326cba8844bd7c79c92493f)

# 7. Restore Expired Contract/WASM

As far as Testnet and Futurenet in Soroban, contract data have a lifetime. In order to maintain and use a smart contract on Soroban, there data and wasm on the network must be maintained.  The process involves retrieving expiration details and utilizing the `Operation.restoreFootprint()` method to obtain ledger keys associated with the contract instance.

[Restore Expired Contract/WASM](https://soroban-snippet.vercel.app/?title=943f3f9207e07751443699f1480500be3bb3636984aa19200452d49a7886cdc5)