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WHApplicationHelper provides access to the current layout
dictionary in its layoutDictionary method. The location
of the layout dictionary can be specified via the
WHLayoutDict property, or you can call
setLayoutDictionary to provide one programmatically in
response to the ApplicationHelperWillFinishInitializing
notification.
Usually you won't access the layout dictionary directly. Rather, the session helper looks up values in the layout dictionary for you to resolve component bindings and values.
The layout dictionary is used to control which components are switched in for each area, page and layout. It has a very flexible structure: you can define entries which apply to all areas in a layout, all pages in a layout, an area in all layouts, a page in all layouts, an area in a page in a layout, etc.
Components that inherit from WHComponent often
resolve their bindings through the layout dictionary rather than
being set directly by a parent component. A component's
color binding can resolve to "blue" in one area, and
"green" in another, depending on the current area, page and
layout.
By default, WireHose will use the value of the user's
currentLayout property to determine which layout to use.
You can override this by calling setCurrentLayout.
WHSessionHelper can also automatically determine which layout to use
by sniffing HTTP request headers during its constructor. This is
useful for temporarily overriding the user's layout preference
depending on the device they are currently using to access the
application.
During development, you can disable caching the layout dictionary
through the WHDisableLayoutDictionaryCaching property.
If this property is true, WHApplication will force the layout
dictionary to be reloaded before each incoming request is handled.
This allows you to make changes in the layout dictionary and see them
immediately without re-launching your application.
Copyright ©2000-2003 Gary Teter. All rights reserved. WireHose is a trademark of Gary Teter.