Pitney Bowes MapXtreme User Manual
Page 104
Chapter 6: Understanding State Management
Terminology
MapXtreme v7.1
104
Developer Guide
Application State - An ASP.NET-defined mechanism for storing state information in memory that
applies to all users and sessions of a web application. See the
at http://msdn2.microsoft.com/en-us/library/ms178594.aspx. See also
Handling Initial
Requests on page 125
.
User state - The saved state of the MapXtreme Session and application state between user
requests. Any changes the user makes to the MapXtreme Session or application must be saved to
the HTTP Session. Changes can be as simple as re-centering the map, or as complicated as a
query to create a thematic map.
Beginning state - The condition of a pooled MapXtreme Session instance when the user accesses
it. There are four possible beginning states:
•
New user to site, the available MapXtreme Session instance from the pool is clean, with the
background map in its initial state.
•
New user to site, the available MapXtreme Session instance from the pool is dirty (map has
changes from another user)
•
Returning user, the available MapXtreme Session instance from the pool is clean.
•
Returning user, the available MapXtreme Session instance from the pool is dirty (map has
changes from this or another user)
MapInfo.Engine.Session.State - A MapXtreme-defined mechanism that determines whether the
MapXtreme Session state will be saved automatically or manually. The automatic Session state
means the entire MapXtreme Session is saved to the HTTP Session. Automatic Session state is set
in the application’s Web.config file in the key:
<add key="MapInfo.Engine.Session.State" value="HttpSessionState" />
Manual Session state means that the developer is responsible for saving state that changes from
one user to another. This is the mechanism to use when building scalable, pooled applications.
Manual Session state is set in the application’s Web.config file in the key:
<add key="MapInfo.Engine.Session.State" value="Manual" />
StateManager - A MapXtreme class with methods and properties to help with saving and restoring
user state in a pooled web application. When MapInfo.Engine.Session.State is set to Manual in the
Web.config file, the application must provide a StateManager class that implements SaveState and
RestoreState methods. See
Implementing a StateManager on page 122
.
sessionState - A standard ASP.NET Web.config element for configuring which storage mechanism
is used for saving user state. Three types:
•
InProc - user state is stored in memory for the lifetime of the ASP.NET Session.
•
StateServer - user state is saved on the server so user changes can be retrieved at a later
time.
•
SQLServer - user state is saved to an SQL Server database for later access.