Pitney Bowes MapXtreme - Manual (Page 76)

Chapter 5: Web Applications, Controls, and Tools
Web Application Request/Response Lifecycle
MapXtreme v7.1 76 Developer Guide
Web Application Request/Response Lifecycle
In order to plan and build an effective web application, you need a solid understanding of the behind
the scenes interactions between the client (browser) and the server (web application). In its simplest
form, a web application is a software application that is accessed through a web browser over an
Internet or intranet connection. The capabilities of the application are presented to a user as an
HTML page, and through user interaction with the elements on the web page, HTTP requests are
sent to a web server for processing. The web server sends back a response that satisfies the user’s
request.
A MapXtreme web application typically presents the user with an image of a map and some tools to
interact with the map. A single request/response cycle could be as simple as the user clicks a Zoom-
In tool to display a different view of the map. Behind the scene, the request to zoom in is sent to the
server. The server processes the request and responds with a refreshed image of the map showing
the new view.
For information on the architecture of a MapXtreme web application, see Chapter 4:
Understanding the MapXtreme Architecture .
For a tutorial on building a MapXtreme application, see Appendix A: How to Create and Deploy a
MapXtreme Application .
For a discussion of creating ASP.NET web applications, see ASP.NET Web Application Projects in
the MSDN library.
Components of a MapXtreme Web Application
The following sections cover the major components that make up a typical MapXtreme web
application, including:
• MapXtreme Session
• Background Map
• MapControl
• Map Tools
MapXtreme Session
The MapXtreme Session is the starting point for all MapXtreme applications. It manages the
initialization of resources needed for a MapXtreme application. The MapXtreme Session also
provides access to other important objects such as Catalog, MapFactory, CoordSysFactory,
Selections, and others.
To access the MapXtreme Session, call the MapInfo.Engine.Session.Current() method. Each thread
in your process has a MapXtreme Session object available. There can be only one MapXtreme
Session per thread and this session cannot be shared by multiple threads. See
Session Interface .
Web applications can have one MapXtreme Session object per user, or pooled MapXtreme
Sessions available to many users. Both development models are discussed in
Chapter 6:
Understanding State Management .