net.sf.jasperreports.engine.json.expression.member.evaluation.ArraySliceExpressionEvaluator Maven / Gradle / Ivy
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* JasperReports - Free Java Reporting Library.
* Copyright (C) 2001 - 2016 TIBCO Software Inc. All rights reserved.
* http://www.jaspersoft.com
*
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* the following license terms apply:
*
* This program is part of JasperReports.
*
* JasperReports is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* JasperReports is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with JasperReports. If not, see .
*/
package net.sf.jasperreports.engine.json.expression.member.evaluation;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Deque;
import java.util.List;
import net.sf.jasperreports.engine.json.JRJsonNode;
import net.sf.jasperreports.engine.json.JsonNodeContainer;
import net.sf.jasperreports.engine.json.expression.EvaluationContext;
import net.sf.jasperreports.engine.json.expression.member.ArraySliceExpression;
import net.sf.jasperreports.engine.json.expression.member.MemberExpression;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.ArrayNode;
/**
* @author Narcis Marcu ([email protected])
*/
public class ArraySliceExpressionEvaluator extends AbstractMemberExpressionEvaluator {
private static final Log log = LogFactory.getLog(ArraySliceExpressionEvaluator.class);
private ArraySliceExpression expression;
public ArraySliceExpressionEvaluator(EvaluationContext evaluationContext, ArraySliceExpression expression) {
super(evaluationContext);
this.expression = expression;
}
@Override
public JsonNodeContainer evaluate(JsonNodeContainer contextNode) {
if (log.isDebugEnabled()) {
log.debug("---> evaluating expression [" + expression +
"] on a node with (size: " + contextNode.getSize() +
", cSize: " + contextNode.getContainerSize() + ")");
}
JsonNodeContainer result = new JsonNodeContainer();
switch(expression.getDirection()) {
case DOWN:
Integer start = getSliceStart(contextNode.getContainerSize());
if (start >= contextNode.getContainerSize()) {
return null;
}
Integer end = getSliceEnd(contextNode.getContainerSize());
if (end < 0) {
return null;
}
if (log.isDebugEnabled()) {
log.debug("start: " + start + ", end: " + end);
}
List containerNodes = contextNode.getContainerNodes();
for (int i = start; i < end; i++) {
JRJsonNode nodeAtIndex = containerNodes.get(i);
if (applyFilter(nodeAtIndex)) {
result.add(nodeAtIndex);
}
}
break;
case ANYWHERE_DOWN:
for (JRJsonNode node: contextNode.getContainerNodes()) {
result.addNodes(goAnywhereDown(node));
}
break;
}
if (result.getSize() > 0) {
return result;
}
return null;
}
private Integer getSliceStart(int containerSize) {
Integer start = expression.getStart();
if (start == null) {
start = 0;
} else if (start < 0) {
start = containerSize + start;
if (start < 0 ) {
start = 0;
}
}
return start;
}
private Integer getSliceEnd(int containerSize) {
Integer end = expression.getEnd();
if (end == null) {
end = containerSize;
} else if (end < 0) {
end = containerSize + end;
} else if (end > containerSize) {
end = containerSize;
}
return end;
}
private List goAnywhereDown(JRJsonNode jrJsonNode) {
List result = new ArrayList<>();
Deque stack = new ArrayDeque<>();
if (log.isDebugEnabled()) {
log.debug("initial stack population with: " + jrJsonNode.getDataNode());
}
// populate the stack initially
stack.push(jrJsonNode);
while (!stack.isEmpty()) {
JRJsonNode stackNode = stack.pop();
JsonNode stackDataNode = stackNode.getDataNode();
addChildrenToStack(stackNode, stack);
// process the current stack item
if (stackDataNode.isArray()) {
if (log.isDebugEnabled()) {
log.debug("processing stack element: " + stackDataNode);
}
ArrayNode newNode = getEvaluationContext().getObjectMapper().createArrayNode();
Integer start = getSliceStart(stackDataNode.size());
if (start >= stackDataNode.size()) {
continue;
}
Integer end = getSliceEnd(stackDataNode.size());
if (end < 0) {
continue;
}
for (int i = start; i < end; i++) {
JRJsonNode nodeAtIndex = stackNode.createChild(stackDataNode.get(i));
if (applyFilter(nodeAtIndex)) {
newNode.add(nodeAtIndex.getDataNode());
}
}
if (newNode.size() > 0) {
result.add(stackNode.createChild(newNode));
}
}
}
return result;
}
@Override
public MemberExpression getMemberExpression() {
return expression;
}
}