WEBDEV Concepts

18 Part 1: Internet: basic concepts How to display a dynamic WEBDEV site WEBDEV session The following operations are performed when displaying a WEBDEV page in Session mode: 1. Page display request. 2. The WEBDEV engine is started. This engine remains on the server until the application is closed. 3. The application context is created. This context remains on the server until the application is closed. 4. The WEBDEV engine executes the server code and builds the HTML page (e.g., from the data in the database). 5. Once the HTML page is entirely built, the server transmits the result to the client (the browser). Page contexts A page context is automatically created on the server each time a page is displayed in the browser. This page context contains all the elements required to build the page viewed by the end user: • global variables, • local variables, • server processes, • database connections, • contexts of data files, etc. The page contexts remain in memory on the server until the end of the WEBDEV session. When the same page is called several times: • If PageDisplay is called to display the page, the page context is deleted and created again. • If PageRefresh is called to display the page, the same page context is used again. Programming The WEBDEV session and the page contexts are automatically managed by default. No programming is required.