org.apache.sling.scripting.sightly.compiler.expression.nodes.PropertyAccess Maven / Gradle / Ivy
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package org.apache.sling.scripting.sightly.compiler.expression.nodes;
import org.apache.sling.scripting.sightly.compiler.expression.ExpressionNode;
import org.apache.sling.scripting.sightly.compiler.expression.NodeVisitor;
/**
* Defines an expression in which an object is queried for a specific property (e.g. {@code obj.prop}).
*/
public final class PropertyAccess implements ExpressionNode {
private final ExpressionNode target;
private final ExpressionNode property;
/**
* Creates a property access node.
*
* @param target the expression for the object being accessed
* @param property the expression identifying the object's accessed property
*/
public PropertyAccess(ExpressionNode target, ExpressionNode property) {
this.target = target;
this.property = property;
}
/**
* Creates a property access node.
*
* @param target the expression for the object being accessed
* @param property the name of the accessed property
*/
public PropertyAccess(ExpressionNode target, String property) {
this.target = target;
this.property = new StringConstant(property);
}
/**
* Builds a chained property access node with the given target and the specified properties.
*
* @param target the target node
* @param properties a non-empty list of property names
* @throws IllegalArgumentException if the list of properties is empty
*/
public PropertyAccess(ExpressionNode target, Iterable properties) {
String lastProp = null;
ExpressionNode result = target;
for (String property : properties) {
if (lastProp != null) {
result = new PropertyAccess(result, new StringConstant(lastProp));
}
lastProp = property;
}
if (lastProp == null) {
throw new IllegalArgumentException("The list of properties must be non-empty");
}
this.target = result;
this.property = new StringConstant(lastProp);
}
@Override
public T accept(NodeVisitor visitor) {
return visitor.evaluate(this);
}
/**
* The object being accessed.
*
* @return a node representing the object being accessed
*/
public ExpressionNode getTarget() {
return target;
}
/**
* Returns the expression node identifying the accessed property.
*
* @return the expression node identifying the accessed property
*/
public ExpressionNode getProperty() {
return property;
}
@Override
public String toString() {
return "PropertyAccess{" +
"target=" + target +
", property='" + property + '\'' +
'}';
}
}