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java.lang.Objectorg.geotools.filter.expression.ExpressionAbstract
public abstract class ExpressionAbstract
Abstract superclass of these Expression implementations.
Contains additional support for "Expression chaining". This allows Expressions to be constructed as a chain of Java commands similar to the use of the java collections api.
Note: Expression chaining is a simple developer convience, it has no effect on the data model exposed by the GeoAPI interfaces.
Idea: We may also be able to teach this implementation to make use of JXPath to extract "attribute values" from Java Beans, DOM, JDOM in addition to the geotools & geoapi FeatureType models. It is a cunning plan - any implementation will make use of this abstract base class.
Field Summary |
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Fields inherited from interface org.opengis.filter.expression.Expression |
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NIL |
Constructor Summary | |
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ExpressionAbstract()
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Method Summary | |
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protected java.lang.Object |
eval(org.opengis.filter.expression.Expression expression,
org.opengis.feature.simple.SimpleFeature feature)
Helper method for subclasses to reduce null checks |
protected java.lang.Object |
eval(Expression expression,
org.opengis.feature.simple.SimpleFeature feature)
Helper method for subclasses to reduce null checks |
java.lang.Object |
evaluate(java.lang.Object object)
Subclass should overide, default implementation returns null |
java.lang.Object |
evaluate(java.lang.Object object,
java.lang.Class context)
Default implementation delegates handling of context conversion to Value utility class. |
Methods inherited from class java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Methods inherited from interface org.opengis.filter.expression.Expression |
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accept |
Constructor Detail |
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public ExpressionAbstract()
Method Detail |
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public java.lang.Object evaluate(java.lang.Object object)
evaluate
in interface org.opengis.filter.expression.Expression
public java.lang.Object evaluate(java.lang.Object object, java.lang.Class context)
Subclasses are expected to make use of the Value utility class (as the easiest way to provide value morphing in confirmance with the Filter specification).
evaluate
in interface org.opengis.filter.expression.Expression
protected java.lang.Object eval(org.opengis.filter.expression.Expression expression, org.opengis.feature.simple.SimpleFeature feature)
expression
- feature
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protected java.lang.Object eval(Expression expression, org.opengis.feature.simple.SimpleFeature feature)
expression
- feature
-
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