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.

Optimize CSS

To ensure efficient delivery to the client, optimize the CSS in a Visualforce page. Optimized CSS also improves caching and reduces load times.

To improve the CSS in a Visualforce page:

  • Externalize style sheets. Remove inline CSS code from the Visualforce page and put it in a separate CSS file. This practice increases the number of initial HTTP requests, but reduces the size of individual pages. After the browser caches the style sheets, the overall request size decreases.
  • Combine all CSS files into a single file, which reduces the number of HTTP requests.
  • Remove comments and extra whitespace. Compress the resulting file for faster downloads.
  • Use static resources to serve CSS files. Style sheets served this way benefit from the caching and the content distribution network (CDN) built into Salesforce.
  • For pages that don't use Salesforce CSS files, set the <apex:page> tag’s showHeaders and standardStylesheets attributes to false. This practice excludes the standard Salesforce CSS files from the generated page header.