Visualforce Developer Guide

Introducing Visualforce
Tools for Visualforce Development
Getting a Quick Start with Visualforce
Customizing the Appearance and Output of Visualforce Pages
Standard Controllers
Standard List Controllers
Custom Controllers and Controller Extensions
Advanced Examples
Override Buttons, Links, and Tabs with Visualforce
Using Static Resources
Creating and Using Custom Components
Dynamic Visualforce Bindings
Dynamic Visualforce Components
Integrate Email with Visualforce
Visualforce Charting
Creating Maps with Visualforce
Render Flows with Visualforce
Templating with Visualforce
Developing Salesforce Apps with Visualforce
Adding Visualforce to a Salesforce AppExchange App
Using JavaScript in Visualforce Pages
Communicating Across the DOM with Lightning Message Service
Visualforce Best Practices
Best Practices for Improving Visualforce Performance
Investigate Performance Issues
Follow Visualforce Design Guidelines
Control Data Size
Cache Frequently Accessed Data
Lazy Load Page Components
Handle Multiple Concurrent Requests
Write Efficient Apex and SOQL
Write Efficient Getter Methods
Optimize Lists and Tables
Optimize the View State
Optimize HTML
Optimize CSS
Optimize JavaScript
Optimize Images
Prevent Fields from Dropping Off the Page
Use the immediate Attribute Carefully
Visualforce Performance Case Study
Best Practices for Accessing Component IDs
Best Practices for Static Resources
Best Practices for Controllers and Controller Extensions
Best Practices for Using Component Facets
Best Practices for Page Block Components
Best Practices for Rendering PDF Files
Best Practices for <apex:panelbar>
Documentation Typographical Conventions
Standard Visualforce Component Reference
Appendices
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.

Lazy Load Page Components

To reduce or delay expensive calculations, use lazy loading. With lazy loading, a page loads its essential components first and delays the other features until the user performs an action that requires the information. This technique gives users faster access to essential features and makes a large page appear more responsive, even though the entire page takes the same total time to load.

To lazy load parts of a Visualforce page, use the following techniques:

  • Use the rerender attribute on Visualforce components to update the component without updating the entire page.
  • Use JavaScript remoting to call functions in your controller and to retrieve ancillary or static data.
  • Create a custom component to show and hide data according to user actions.

When you lazy load a page, consider the number of users and the amount of data you expect the page to use. Watch out for limits such as the concurrent API call limit. For example, if a navigation tree only loads elements as needed, the number of queries can end up out of proportion to the data.