Mapped Properties

Some beans have properties that are Java maps. A map is like an array except that each member of the array is identified by a key. You can therefore retrieve a specific member of such a property by specifying the key that identifies it. You can, for example, access a section page area called "header" area as follows:

${pool.rootElement.areas['header']}

In this example pool is a PresentationPool bean representing the section page requested by a user. Its rootElement property is a PresentationElement bean representing the section page's root group or grid. The grid's areas property is a mapped property containing all the areas in the grid, each of which can be accessed by specifying its key (in this case, header).

The JSP expression language allows you replace the key specification syntax shown above with simple dot notation. You can therefore also access the "header" area as follows:

${pool.rootElement.areas.header}

All of the examples in this manual use this simpler method of addressing mapped properties.