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
Dynamic Output in Expressions
Conditional Expressions
Data Binding Between Components
Value Providers
Expression Evaluation
Expression Operators Reference
Expression Functions Reference
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
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.

Dynamic Output in Expressions

The simplest way to use expressions is to output dynamic values.

Values used in the expression can be from component attributes, literal values, booleans, and so on. For example:

1{!v.desc}

In this expression, v represents the view, which is the set of component attributes, and desc is an attribute of the component. The expression is simply outputting the desc attribute value for the component that contains this markup.

If you're including literal values in expressions, enclose text values within single quotes, such as {!'Some text'}.

Include numbers without quotes, for example, {!123}.

For booleans, use {!true} for true and {!false} for false.