The abstract class for all filter rules.
Rules are used to define filters that can be applied on data sources. A rule is usually a combination of 3 things:
- a property name, for example 'city_name'
- an operator, for example 'is equal to'
- and an expression, for example 'Chicoutimi'.
A rule is useful to hold those properties and change them on the fly. For example, changing an operator from 'is equal to' to 'like'.
Also, a rule is especially useful for its
value getter, which returns
the combination of properties described above or
null if there are some
value getter can be watched and used when the value is
When the operator is
properties are used instead of
The expression of the rule. The expression and boundaries are mutually exclusives.
Note: exported (instead of private) due to the problem with the
compiler. See the getter/setter methods below... As a setter, the
expression property would support being bond to an
it, it can't unless we expose the property directly.
(protected) listenerKeys: Array:.<!ol.EventsKey:>
expression property does not have conventionnal getter/setters
method because of a limitation of the compiler. It doesn't support
yet having such methods being extended in child classes.
Reset the following properties to
null: expression, lowerBoundary,