Fixing Performance Warnings

A few common performance anti-patterns in code prompt the framework to log warning messages to the browser console. Fix the warning messages to speed up your components!

The warnings display in the browser console only if you enabled debug mode.

• <aura:if> —Clean Unrendered Body —Clean Unrendered Body

  This warning occurs when you change the isTrue attribute of an <aura:if> tag from true to false in the same rendering cycle. The unrendered body of the <aura:if> must be destroyed, which is avoidable work for the framework that slows down rendering time.

• <aura:iteration> —Multiple Items Set —Multiple Items Set

  This warning occurs when you set the items attribute of an <aura:iteration> tag multiple times in the same rendering cycle.

See Also

• Salesforce Help: Enable Debug Mode for Lightning Components

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Introducing Aura Components

Quick Start

Creating Components

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

Performance Settings

Fixing Performance Warnings

<aura:if> —Clean Unrendered Body —Clean Unrendered Body

<aura:iteration> —Multiple Items Set —Multiple Items Set

Reference

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