Apex Developer Guide

Apex Developer Guide
Getting Started with Apex
Writing Apex
Running Apex
Debugging, Testing, and Deploying Apex
Apex Language Reference
Apex DML Operations
ApexPages Namespace
AppLauncher Namespace
Approval Namespace
Auth Namespace
Cache Namespace
Canvas Namespace
ApplicationContext Interface
CanvasLifecycleHandler Interface
CanvasLifecycleHandler Methods
excludeContextTypes()
onRender(renderContext)
ContextTypeEnum Enum
EnvironmentContext Interface
RenderContext Interface
Test Class
Canvas Exceptions
ChatterAnswers Namespace
commercepayments Namespace
ConnectApi Namespace
Database Namespace
Datacloud Namespace
DataSource Namespace
Dom Namespace
EventBus Namespace
Flow Namespace
KbManagement Namespace
Messaging Namespace
Metadata Namespace
Process Namespace
QuickAction Namespace
Reports Namespace
Schema Namespace
Search Namespace
Sfc Namespace
Site Namespace
Support Namespace
System Namespace
TerritoryMgmt Namespace
TxnSecurity Namespace
UserProvisioning Namespace
VisualEditor Namespace
wave Namespace
Appendices
Glossary
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excludeContextTypes()

Lets the implementation exclude parts of the CanvasRequest context, if the application does not need it.

Signature

public Set<Canvas.ContextTypeEnum> excludeContextTypes()

Return Value

Type: SET<Canvas.ContextTypeEnum>

This method must return null or a set of zero or more ContextTypeEnum values. Returning null enables all attributes by default. ContextTypeEnum values that can be set are:
  • Canvas.ContextTypeEnum.ORGANIZATION
  • Canvas.ContextTypeEnum.RECORD_DETAIL
  • Canvas.ContextTypeEnum.USER
See ContextTypeEnum for more details on these values.

Usage

Implement this method to specify which attributes to disable in the context of the canvas app. A disabled attribute will set the associated canvas context information to null.

Disabling attributes can help improve performance by reducing the size of the signed request and canvas context. Also, disabled attributes do not need to be retrieved by Salesforce, which further improves performance.

See the Canvas Developer Guide for more information on context information in the Context object that’s provided in the CanvasRequest.

Example

This example implementation specifies that the organization information will be disabled in the canvas context.

1public Set<Canvas.ContextTypeEnum> excludeContextTypes() {
2    Set<Canvas.ContextTypeEnum> excluded = new Set<Canvas.ContextTypeEnum>();
3    excluded.add(Canvas.ContextTypeEnum.ORGANIZATION);
4    return excluded;
5}