How do I call DaisyDiff to compare two HTML files?
I need to create a difference between two HTML documents in my application. I found a library called DaisyDiff that can do this. It has an API that looks like this:
/**
* Diffs two html files, outputting the result to the specified consumer.
*/
public static void diffHTML(InputSource oldSource, InputSource newSource,
ContentHandler consumer, String prefix, Locale locale)
throws SAXException, IOException
I don't know anything about SAX and I can't figure out what to pass as the third argument. After scrolling through https://code.google.com/p/daisydiff/source/browse/trunk/daisydiff/src/java/org/outerj/daisy/diff/Main.java I wrote this method:
@Override
protected String doInBackground(String... params)
{
try {
String oldFileName = params[0],
newFileName = params[1];
ByteArrayOutputStream os = new ByteArrayOutputStream();
FileInputStream oldis = null, newis = null;
oldis = openFileInput(oldFileName);
newis = openFileInput(newFileName);
SAXTransformerFactory tf = (SAXTransformerFactory) TransformerFactory
.newInstance();
TransformerHandler result = tf.newTransformerHandler();
result.setResult(new StreamResult(os));
DaisyDiff.diffHTML(new InputSource(oldis), new InputSource(newis), result, "", Locale.getDefault());
Log.d("diff", "output length = " + os.size());
return os.toString("Utf-8");
}catch (Exception e){
return e.toString();
}
}
I have no idea it even makes sense. It doesn't work, nothing is written to the output. Please help me with this. Thanks in advance.
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According to how it is HtmlTestFixture.diff
coded (internally src/test/java
DaisyDiff
), you need to give it instructions on how the result should be formatted. Have you tried adding below setOutputProperty(...)
calls?
@Test
//@Test comes from TestNG and is not related to DaisyDiff
public void daisyDiffTest() throws Exception {
String html1 = "<html><body>var v2</body></html>";
String html2 = "<html> \n <body> \n Hello world \n </body> \n </html>";
try {
StringWriter finalResult = new StringWriter();
SAXTransformerFactory tf = (SAXTransformerFactory) SAXTransformerFactory.newInstance();
TransformerHandler result = tf.newTransformerHandler();
result.getTransformer().setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
result.getTransformer().setOutputProperty(OutputKeys.INDENT, "yes");
result.getTransformer().setOutputProperty(OutputKeys.METHOD, "html");
result.getTransformer().setOutputProperty(OutputKeys.ENCODING, "UTF-8");
result.setResult(new StreamResult(finalResult));
ContentHandler postProcess = result;
DaisyDiff.diffHTML(new InputSource(new StringReader(html1)), new InputSource(new StringReader(html2)), postProcess, "test", Locale.ENGLISH);
System.out.println(finalResult.toString());
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Let's do this, my output looks like this. Now I can paste this into an HTML file, include the correct css and js files, and get nice output.
<span class="diff-html-removed" id="removed-test-0" previous="first-test" changeId="removed-test-0" next="added-test-0">var v2</span><span class="diff-html-added" previous="removed-test-0" changeId="added-test-0" next="last-test"> </span><span class="diff-html-added" id="added-test-0" previous="removed-test-0" changeId="added-test-0" next="last-test">Hello world </span>
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