/*
* Copyright 2014 Daniel Bechler
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package de.danielbechler.diff.node;
import de.danielbechler.diff.path.NodePath;
import de.danielbechler.util.Strings;
/**
* @author Daniel Bechler
*/
public class PrintingVisitor implements DiffNode.Visitor
{
private final Object working;
private final Object base;
public PrintingVisitor(final Object working, final Object base)
{
this.base = base;
this.working = working;
}
public void node(final DiffNode node, final Visit visit)
{
if (filter(node))
{
final String text = differenceToString(node, base, working);
print(text);
}
}
protected boolean filter(final DiffNode node)
{
return (node.isRootNode() && !node.hasChanges())
|| (node.hasChanges() && !node.hasChildren());
}
protected String differenceToString(final DiffNode node, final Object base, final Object modified)
{
final NodePath nodePath = node.getPath();
final String stateMessage = translateState(node.getState(), node.canonicalGet(base), node.canonicalGet(modified));
final String propertyMessage = String.format("Property at path '%s' %s", nodePath, stateMessage);
final StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append(propertyMessage);
if (node.isCircular())
{
stringBuilder.append(" (Circular reference detected: The property has already been processed at another position.)");
}
return stringBuilder.toString();
}
protected void print(final String text)
{
System.out.println(text);
}
private static String translateState(final DiffNode.State state, final Object base, final Object modified)
{
if (state == DiffNode.State.IGNORED)
{
return "has been ignored";
}
else if (state == DiffNode.State.CHANGED)
{
return String.format("has changed from [ %s ] to [ %s ]",
Strings.toSingleLineString(base),
Strings.toSingleLineString(modified));
}
else if (state == DiffNode.State.ADDED)
{
return String.format("has been added => [ %s ]", Strings.toSingleLineString(modified));
}
else if (state == DiffNode.State.REMOVED)
{
return String.format("with value [ %s ] has been removed", Strings.toSingleLineString(base));
}
else if (state == DiffNode.State.UNTOUCHED)
{
return "has not changed";
}
else if (state == DiffNode.State.CIRCULAR)
{
return "has already been processed at another position. (Circular reference!)";
}
return '(' + state.name() + ')';
}
}