Lightning Aura Components Developer Guide

Introducing Aura Components
Quick Start
Creating Components
Component Names
Create Aura Components in the Developer Console
Create Aura Components Using Salesforce CLI
Component Markup
Component Namespace
Component Bundles
Component IDs
HTML in Components
CSS in Components
Component Attributes
Using Expressions
Component Composition
Component Body
Component Facets
Controlling Access
Using Object-Oriented Development
Best Practices for Conditional Markup
Aura Component Versioning for Managed Packages
Base Components with Minimum API Version Requirements
Validations for Aura Component Code
Validation When You Save Code Changes
Validation During Development Using ESLint
Aura Component Validation Rules
Using Labels
Localization
Working with Lightning Base Components
Supporting Accessibility
Writing Documentation for the Component Library
Using Components
Communicating with Events
Communicating Across the DOM with Lightning Message Service
Creating Apps
Styling Apps
Developing Secure Code
Using JavaScript
Working with Salesforce Data
Testing Components
Debugging
Performance
Reference
PDF

Note: This release is in preview. Features described here don’t become generally available until the latest general availability date that Salesforce announces for this release. Before then, and where features are noted as beta, pilot, or developer preview, we can’t guarantee general availability within any particular time frame or at all. Make your purchase decisions only on the basis of generally available products and features.

Validation When You Save Code Changes

Aura component JavaScript code is validated when you save it. Validation ensures that your components are written using best practices and avoid common pitfalls that can make them incompatible with Lightning Locker. Validation happens automatically when you save Aura component resources in the Developer Console, in your favorite IDE, and via API.

Validation failures are treated as errors and block changes from being saved. Error messages explain the failures. Depending on the tool you’re using, these errors are presented in different ways. For example, the Developer Console shows an alert for the first error it encounters (1), and lists all of the validation errors discovered in the Problems tab (2).Save validation errors in the Developer Console

Validations are applied only to components set to API version 41.0 and later. If the validation service prevents you from saving important changes, set the component version to API 40.0 or earlier to disable validations temporarily. When you’ve corrected the coding errors, return your component to API 41.0 or later to save it with passing validations.