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 the View State

To maintain a Visualforce page’s view state, Lightning Platform stores the state of components, field values, and the controller as an encrypted string in a hidden form element. The view state has a limit of 170 KB. A large view state requires longer processing times for each request, including serialization and deserialization time, and encryption and decryption time. If you reduce the view state size, then your page can load faster and stall less often.

To examine a Visualforce page’s view state, set the Development Mode and the Show View State in Development Mode user permissions. The View State tab in the development mode footer displays the distribution of the view state. Make sure you know the view state size of each page, and test with large data volumes to prevent issues that can occur after deployment.

To reduce the view state:

  • Use filters and pagination to reduce data that requires state.
  • Declare an instance variable with a transient keyword if the variable is only useful for the current request. A transient variable isn’t included in the view state.
  • Refine your SOQL calls to return only data that's relevant to the Visualforce page.
  • Reduce the number of components that your page depends on.
  • Make data read-only. Use the <apex:outputText> component instead of the <apex:inputField> component.
  • Use JavaScript remoting. Unlike the <apex:actionFunction> component, JavaScript remoting doesn’t require an <apex:form> component. JavaScript remoting doesn’t reduce the overall view state of a page, but your page generally performs better without the need to transmit, serialize, and deserialize the view state. The tradeoffs are the loss of the reRender attribute and the necessity of additional JavaScript code to handle callbacks.