This is a fork of DaisyDiff in Java project. The documentation of initial project can be found here: daisydiff.github.io.

The aim of this project is not to provide a standalone tool of diffing HTMLs, which DaisyDiff provides among others, but to provide a library of diffing HTMLs to other Java applications.

Installation

Adding as a Dependency

Artifacts of this project are uploaded to Maven Central Repository, so to use it as a library in your project, add the following dependency to your pom.xml:

<dependency>
    <groupId>ch.sbb.html5diff</groupId>
    <artifactId>html5diff</artifactId>
    <version>1.4.5</version>
</dependency>

Usage

Usage as a library

import java.io.StringReader;
import java.io.StringWriter;

import java.util.Locale;

import javax.validation.constraints.NotNull;

import javax.xml.transform.OutputKeys;
import javax.xml.transform.sax.SAXTransformerFactory;
import javax.xml.transform.sax.TransformerHandler;
import javax.xml.transform.stream.StreamResult;

import lombok.experimental.UtilityClass;

import org.apache.commons.lang3.tuple.Pair;

import org.outerj.daisy.diff.helper.NekoHtmlParser;
import org.outerj.daisy.diff.html.HTMLDiffer;
import org.outerj.daisy.diff.html.HtmlSaxDiffOutput;
import org.outerj.daisy.diff.html.TextNodeComparator;
import org.outerj.daisy.diff.html.dom.DomTreeBuilder;
        
import org.xml.sax.InputSource;

@UtilityClass
public class DiffToolUtils {
    public String computeDiff(@NotNull Pair<String, String> pairToDiff) {
        try {
            StringWriter finalResult = new StringWriter();
            SAXTransformerFactory tf = (SAXTransformerFactory) TransformerFactory.newInstance();

            TransformerHandler handler = tf.newTransformerHandler();
            handler.getTransformer().setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
            handler.getTransformer().setOutputProperty(OutputKeys.INDENT, "no");
            handler.getTransformer().setOutputProperty(OutputKeys.METHOD, "html");
            handler.getTransformer().setOutputProperty(OutputKeys.ENCODING, "UTF-8");
            handler.setResult(new StreamResult(finalResult));

            Locale locale = Locale.getDefault();

            NekoHtmlParser parser = new NekoHtmlParser();

            InputSource oldSource = new InputSource(new StringReader(pairToDiff.getLeft()));
            InputSource newSource = new InputSource(new StringReader(pairToDiff.getRight()));

            DomTreeBuilder oldHandler = new DomTreeBuilder();
            parser.parse(oldSource, oldHandler);
            TextNodeComparator leftComparator = new TextNodeComparator(oldHandler, locale);

            DomTreeBuilder newHandler = new DomTreeBuilder();
            parser.parse(newSource, newHandler);
            TextNodeComparator rightComparator = new TextNodeComparator(newHandler, locale);

            new HTMLDiffer(new HtmlSaxDiffOutput(handler, "diff")).diff(leftComparator, rightComparator);

            return finalResult.toString();
        } catch (Exception ex) {
            return "Error occurred while getting HTML diff";
        }
    }
}

Usage in a CLI

There is a side project HTML5Diff CLI which provides CLI interface to functionality of this project. Please, read documentation of that project about how to use it.

Project Build

This project is built using Maven. To compile the project, run the following command:

$ mvn compile

To compile the project and run the tests, use:

$ mvn test

To compile the project, run the tests, and build the (thin) jar file, use:

$ mvn package

To compile the project, run the tests, build the (thin) jar file and install it to local Maven repository, use:

$ mvn install