public abstract class DefaultExpressionVisitor extends Object implements ExpressionVisitor
This class implements the full ExpressionVisitor interface and will visit every Filter member of an Expression object. This class performs no actions and is not intended to be used directly, instead extend it and overide the methods for the Expression type you are interested in. Remember to call the super method if you want to ensure that the entire expression tree is still visited.
FilterVisitor allProperties = new DefaultExpressionVisitor(){
public Object visit( PropertyName expr, Object data ) {
Set set = (Set) data;
set.addAll(expr.getPropertyName());
return set;
}
};
Set set = (Set) allProperties.accept(allFids, new HashSet());
Constructor and Description |
---|
DefaultExpressionVisitor() |
Modifier and Type | Method and Description |
---|---|
Object |
visit(Add expression,
Object data) |
Object |
visit(Divide expression,
Object data) |
Object |
visit(Function expression,
Object data) |
Object |
visit(Literal expression,
Object data) |
Object |
visit(Multiply expression,
Object data) |
Object |
visit(NilExpression expression,
Object data)
Used to visit a Expression.NIL, also called for
null where an expression is
expected. |
Object |
visit(PropertyName expression,
Object data) |
Object |
visit(Subtract expression,
Object data) |
public Object visit(NilExpression expression, Object data)
ExpressionVisitor
null
where an expression is
expected.
This is particularly useful when doing data transformations, as an example when using a StyleSymbolizer Expression.NIL can be used to represent the default stroke color.
visit
in interface ExpressionVisitor
public Object visit(Add expression, Object data)
visit
in interface ExpressionVisitor
public Object visit(Divide expression, Object data)
visit
in interface ExpressionVisitor
public Object visit(Function expression, Object data)
visit
in interface ExpressionVisitor
public Object visit(Literal expression, Object data)
visit
in interface ExpressionVisitor
public Object visit(Multiply expression, Object data)
visit
in interface ExpressionVisitor
public Object visit(PropertyName expression, Object data)
visit
in interface ExpressionVisitor
public Object visit(Subtract expression, Object data)
visit
in interface ExpressionVisitor
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