Example for Node Exclusion

[groliffe]

Have you got a simple java example of how to do node exclusion in a comparison? I looked at the inclusion Groovy tests, but couldn't see how they worked.

Cheers

Lance

[SQiShER]

Actually the Acceptance Tests show all the possible options.

Can you show me your code, so I can help you based on that?

[groliffe]

Ok, a simple test - Book just has three fields, how would you get it to ignore the author field ?

import static org.junit.Assert.*;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import de.danielbechler.diff.ObjectDiffer;
import de.danielbechler.diff.ObjectDifferBuilder;
import de.danielbechler.diff.node.DiffNode;
import de.danielbechler.diff.node.PrintingVisitor;

public class TestDiff {

private ObjectDiffer objectDiffer;

@Before
public void setUp() throws Exception {
    objectDiffer = ObjectDifferBuilder.buildDefault();
}

@Test
public void test2() {

        Book original = new Book();
        original.setTitle("A Book");
        original.setAuthor("me");
        original.setISBN("1234");

        Book mod = new Book();
        mod.setTitle("A Book");
        mod.setAuthor("him");
        mod.setISBN("1234");

        DiffNode root = objectDiffer.compare(mod, original);

        System.err.println(root.isChanged());
        root.visit(new PrintingVisitor(mod, original));
}

}

[groliffe]

Thanks for the acceptance tests link (I was just looking in test...) and I can do the simple exclusion with

builder = ObjectDifferBuilder.startBuilding();
builder.inclusion().exclude().propertyName("author");

but say I had another object inside the Book object, also with a property called 'author' - how would I just exclude that embedded field, so

Book book = new Book();
book.setAuther("me");

Tester test = new Tester();
test.setAuthor("him");

book.setTester(test);

What's the pattern for building these type of exclusions?

builder.inclusion().exclude().propertyName("author"); eccludes that field at all levels and
builder.inclusion().exclude().node(NodePath.with("tester")) excludes everything in the subnode, and
builder.inclusion().exclude().node(NodePath.with("tester")).propertyName("author"); doesn't seem to work either?

[SQiShER]

Ah, interesting. This definitely needs some documentation. To exclude a specific node, the NodePath needs to be an absolute path to the property. So instead of

builder.inclusion().exclude().node(NodePath.with("tester")).propertyName("author")

you need to write

builder.inclusion().exclude().node(NodePath.with("tester", "author"))

But I actually like the way you tried to use it. I'm tempted to make this a feature. 😉

[SQiShER]

Did it work? If not, feel free to reopen this issue.

[groliffe]

Yep - Just what I needed.

Cheers

Lance