Noteworthy Points - Evision

1. eVision Studio applications are based on the Model/View/Controller

(MVC) architecture. MVC is a software development paradigm that enhances the task of building software systems, particularly those that generate multiple, synchronized presentations of the same data.

2. The Model object represents the data in a program, which manages

behaviors and data within an application. The Model responds to requests for information about its current state (typically requested by the View) and responds to instructions to change its state (typically requested by the Controller). The View object manages the visual display of the Model data; for example, displaying graphics and text to users in a browser. The Controller object enables user interaction with the Model data; for example, mouse and keyboard inputs from the user, which instruct the Model and/or View to perform an action.

3. eVision Studio’s application architecture fully supports the MVC

paradigm. In an eVision Studio web application, user input, modeling of the external world, and visual feedback are managed by MVC objects, where each object is specialized for its task. For example a. The Model, represented by the Page Flow, contains the business logic (Object Type Definitions and Collaborations) that interacts with the back-end system applications. b. The View contains the pages created with the JavaServer Pages™ technology (“JSP™ pages”) that are generated with the Page Layout Designer. c. The Controller is the web-enabled Page Flow created with the Page Flow Designer. The Controller orchestrates the sequence of pages being sent to the browser in response to user actions.

4. Each object must have a logical name (the LName property). The Page Flow Designer uses the LName property as the identifier for Page Layout objects. eVision Studio requires that the first character of the LName property be capitalized. If you enter a value that begins with a lowercase character, then eVision Studio capitalizes the character. For example, myValue is changed to MyValue. A description of each property is provided in two ways: a. In a property description box at the bottom of the Properties tab b. As a tooltip when you place the mouse pointer over a property name

5. In the Properties tab, some of the property names appear in blue. The blue color indicates that these properties also appear in the mapper portion of the Page Flow Designer.

6. At runtime, the browser determines the final style based on inheritance and cascading rules. The final style might be different from what you assign by using the Class property.

7. You must assign a value to the Page Link, even if the value is dynamically assigned at runtime.

8. eVision Studio allocates 20 extra pixels to the width of a dynamic table. If a vertical scrollbar is needed at runtime, these pixels enable the scrollbar to appear correctly.

9. When a user presses the Close button, eVision Studio sends an exception for pending requests to the Page Flow, ends the session, and closes the browser.If you want the Page Flow to continue after the user presses the Close button, then you must catch the exception.

10. When a user presses the Logout button, eVision Studio sends an exception for pending requests to the Page Flow, invalidates the session, and returns the user to the beginning of the Page Flow. If you want the Page Flow to continue after the user presses the Logout button, then you must catch the exception.

11. If a session timeout occurs, eVision Studio sends a page exception and invalidates the session. By default, the session timeout is 60 minutes.

12. A portal is a web site that serves as a gateway for web-based services and applications. A portlet is a Java-based web component that runs inside a portal. JSR 168 is a standard that ensures interoperability between portals and portlets. You can generate a JSR 168-compliant portlet in eVision Studio, and then expose the portlet in a JSR 168compliant portal such as Sun Java™ System Portal Server.