Scope in JSF Controllers - hmislk/hmis GitHub Wiki
Scope in JSF Controllers
JSF controllers are crucial components for managing application state and behavior. Understanding the different scopes helps in efficient resource management and ensuring proper data flow within the application.
- Application Scope
The Application Scope persists throughout the lifecycle of the application and is accessible to all users. This scope is ideal for storing data shared across multiple users or sessions.
Application Controller
java Copy code #{myApplicationController.count} #{myApplicationController.calculateBillNumber} Note:
In clustered environments, ensure data consistency across all nodes. 2. Session Scope
The Session Scope maintains data for a particular user session. It's ideal for storing user-specific information and maintaining state across multiple requests.
Session Controller
java Copy code #{mySessionController.count} #{mySessionController.calculateBillNumber} Usage Notes:
In a non-clustered environment, session data persists as long as the user's session remains active. Different sessions are created for each user, browser, or device. 3. View Scope
The View Scope keeps data tied to a particular JSF view. It's suitable for managing state within a single page or component.
Usage Scenarios:
Each tab or window in the same browser creates a separate view instance. Different users, browsers, or computers result in distinct view instances. 4. Request Scope
The Request Scope maintains data for the duration of a single HTTP request. It's suitable for temporary data needed during request processing.
- Dependent Scope
The Dependent Scope is tied to the lifecycle of its owning bean. It's created and destroyed with the bean itself, making it suitable for managing resources dependent on the bean's lifecycle.
Scope Considerations:
Choose the appropriate scope based on data longevity and accessibility requirements. Be mindful of resource usage, especially in clustered environments, to ensure scalability and performance. Understanding and effectively utilizing these scopes in JSF controllers can lead to more efficient and scalable web applications.