Specifies ExpressionInterface classes
that can (potentially) contain a data item as part of their expression. For example,
the expression can be used in a ResourceAwareStringExpression (RASE). For example, SUM(<<DataItem1>>).
Or the expression may be modeled as an expression tree for example, a ConditionalExpression on a
DataItem filter. Note the DataItems can be nested to any depth within
an expression. In the RASE example above, <<DataItem1>> may contain an expession
with other dataitems in it. This interface does not impose limitations
on anything else the expression may contain.
Given these types of expressions, it is very useful to find out if such expressions
contain user typed aggregation, or obtain a list of leaf dataitems.
There may be other uses in the future.
For example, there is a need to run a query with detail usage on a dataitem
for supporting ROLAP with calculated items.
Using this interface a list of leaf items may be obtained from the dataitem's expression
which can then be used in a detail query.
Field Summary
Fields inherited from interface com.sas.iquery.metadata.business.ModelItem
Return a list of leaf data items (dataitems
which do not contain measure dataitems as part of their expression).
This will allow us to get dataitems which can return detail information
by ignoring their aggregate function.
Duplicates will be removed. If the same leaf dataitem appears
more than once in the expression, the returned list will contain the dataitem
only once.
DataItem can be both an expression and a leaf data item.
Therefore, a data item when treated as an expression, may return itself
from this method.
Returns:
List of DataItem objects or an empty list if none found.
Return true if this expression or any of its dataitems
have an aggregation in their expression text.
For example, the user may have typed "SUM(X) + SUM(Y)"
in the expression editor.
Returns:
true, if there is at least one user typed aggregation,
false otherwise
