Lightning Components Developer Guide

What is the Lightning Component Framework?
Quick Start
Creating Components
Create Lightning Components in the Developer Console
Component Markup
Component Namespace
Component Bundles
Component IDs
HTML in Components
CSS in Components
Component Attributes
Component Composition
Component Body
Component Facets
Best Practices for Conditional Markup
Component Versioning
Using Expressions
Using Labels
Localization
Providing Component Documentation
Working with Base Lightning Components
Working with UI Components
Supporting Accessibility
Using Components
Communicating with Events
Creating Apps
Debugging
Fixing Performance Warnings
Reference
PDF

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Component Markup

Component resources contain markup and have a .cmp suffix. The markup can contain text or references to other components, and also declares metadata about the component.

Let's start with a simple "Hello, world!" example in a helloWorld.cmp component.

This is about as simple as a component can get. The "Hello, world!" text is wrapped in the <aura:component> tags, which appear at the beginning and end of every component definition.

Components can contain most HTML tags so you can use markup, such as <div> and <span>. HTML5 tags are also supported.

Case sensitivity should be respected as your markup interacts with JavaScript, CSS, and Apex.

Note

Use the Developer Console to create components.

Component Naming Rules

A component name must follow these naming rules:

  • Must begin with a letter
  • Must contain only alphanumeric or underscore characters
  • Must be unique in the namespace
  • Can’t include whitespace
  • Can’t end with an underscore
  • Can’t contain two consecutive underscores