The Mediator Pattern in LWC: How Sibling Components Really Communicate
Summary
In Lightning Web Components, sibling components cannot communicate directly. This article explains using the Mediator Pattern, where the parent component coordinates communication by catching child events and passing data via @api properties to siblings. This approach improves scalability, reusability, and aligns with Salesforce best practices, offering a robust, maintainable pattern for component communication.
Takeaways
- Implement sibling communication via the parent component as the mediator.
- Use custom events for child-to-parent communication in LWC.
- Pass data to sibling components using @api public properties.
- Keep sibling components independent and reusable by avoiding direct communication.
- Follow the Mediator Pattern to align with LWC best practices and scalability.
Sibling component communication is one of the most confusing topics for developers working with Lightning Web Components (LWC). At first glance, it feels natural to expect sibling components to communicate directly with each other. When that doesn’t work, many developers immediately reach for Pub-Sub , often without fully understanding the long-term implications. Salesforce encourages a more structured and scalable communication approach where the parent component acts as the coordinator. This design approach is known as the Mediator Pattern , and it is the recommended, enterprise-grade solution for sibling communication in LWC. Let’s Learn with a Real-Time Example Business Scenario Imagine you are building a Lightning page that includes the following components: Account List – Displays a list of Accounts Account Details – Displays details of the selected Account When a user selects an Account from the list, the Account Details component should update automatically.