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Oracle Module for External Data Feeds
This tutorial will guide you through building an Oracle module using Ignite CLI, which fetches external data feeds for blockchain applications. We'll focus on backend development, laying the foundation for a robust oracle system.
Overview
Oracles are essential for blockchains to interact with external data. They enable smart contracts to access off-chain data like weather, prices, real-world information or data from other IBC enabled blockchains.
Prerequisites
Steps to Create an Oracle Module
Step 1: Scaffold a New Blockchain:
Create a new blockchain project using Ignite CLI:
Step 2: Scaffold the Oracle Module
Generate the Oracle module:
This command creates a new module with IBC capabilities, ideal for building an oracle that can interact with other blockchains.
Step 3: Define Data Structures
Scaffold the necessary types for your oracle. For example, to create a data structure for storing external data:
Here,
externalData
stores key-value pairs representing data fetched from external sources.Step 4: Implement Oracle Functionality
Create Oracle Handler
In your
x/oracle/handler.go
, define the logic to process oracle-related transactions. For instance, adding a function to handle data submission:Update Module Configuration
In
x/oracle/module.go
, register your message handlers:Step 5: Implement Data Fetching Logic
Create a new Go file
x/oracle/external_data.go
to handle external data fetching:Call this function within your message handlers or other appropriate places in your module to fetch and store data.
Step 6: Register and Handle Oracle Queries
Define queries to retrieve stored data in
x/oracle/keeper/grpc_query.go
:Step 7: Add Necessary CLI and gRPC Configurations
Ensure that your module's CLI commands and gRPC endpoints are properly configured to interact with the oracle functionality.
Conclusion
With these steps, you have laid the foundation for an Oracle module that can fetch and handle external data feeds. This module can be expanded with more complex data handling, authentication mechanisms for data sources, and integration with smart contracts or other blockchain functionalities.