Mon, 07 Feb 2005

Quotes Manager Project -- Day 13

As I explore my solution, I see that subsequent calls to add a new quote actually append the entire document to the previous document. That's obviously not what I want.

Ah, solved the problem I found yesterday. The hasText method in PersonPanel was messed up. Just an annoying firstName.getText() != "" vs. !"".equals(firstName.getText()) issue. I didn't think I would need to write a test for something that trivial. Stupid mistake.

Now for the second problem... Before the XML output is generated from the Document, I need to somehow empty the file. Not sure how to do that off the top of my head with only an OutputStream. Exploring...grrr, can't do it. I really don't want XmlQuoteListener to have to use files becauses that makes the testing harder.

I'm feeling stuck, so I'll write a failing test...

    public void testShouldWriteDocumentToFileWhenUpdatedMultipleTimes() throws Exception {
        Document document = parseStub();

        ByteArrayOutputStream output = new ByteArrayOutputStream();
        QuoteListener listener = new XmlQuoteListener(document, output);

        assertEquals("", output.toString());

        listener.update();
        listener.update();

        String expectedOutput = documentToText(document);
        assertEquals(expectedOutput, output.toString());
    }

How about a factory to provide OutputStreams? That way we could get a new one with every call to update...

    public void testShouldWriteDocumentToFileWhenUpdatedMultipleTimes() throws Exception {
        Document document = parseStub();

        ByteArrayOutputStream output = new ByteArrayOutputStream();

        Mock factory = mock(OutputFactory.class);
        OutputStream ignored = new ByteArrayOutputStream();
        factory.expects(atLeastOnce()).method("newOutput")
               .will(onConsecutiveCalls(returnValue(ignored), returnValue(output)));

        QuoteListener listener = new XmlQuoteListener(document, (OutputFactory) factory.proxy());

        assertEquals("", output.toString());

        listener.update();
        listener.update();

        String expectedOutput = documentToText(document);
        assertEquals(expectedOutput, output.toString());
    }

public class XmlQuoteListener implements QuoteListener {
    private final Document document;
    private final OutputFactory factory;

    public XmlQuoteListener(Document document, OutputFactory factory) {
        this.document = document;
        this.factory = factory;
    }

    public void update() {
        try {
            Transformer transformer = TransformerFactory.newInstance().newTransformer();
            Source source = new DOMSource(document);
            Result result = new StreamResult(factory.newOutput());
            transformer.transform(source, result);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

    public static void main(String[] args) throws Exception {
        JFrame frame = new JFrame(TITLE);

        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = factory.newDocumentBuilder();

        final String xmlFile = "play.xml";
        Document document = builder.parse(xmlFile);

        QuoteListener listener = new XmlQuoteListener(document, new OutputFactory() {
            public OutputStream newOutput() throws IOException {
                return new FileOutputStream(xmlFile);
            }
        });

        QuoteManager manager = new XmlQuoteManager(document);
        manager.addListener(listener);

        QuoteManagerPanel quoterManager = new QuoteManagerPanel(manager);
        frame.getContentPane().add(quoterManager);

        frame.pack();
        frame.setVisible(true);
    }

So let's look back at the initial goals and see where we are...

• I want to change the quotes page to be sorted by quoter author. DONE. There should be a list of all the quoters at the top. NOT DONE. Their names should link down to their quotes on the page below. NOT DONE.
• I want to use a simple Swing application to manage the quotes. FIRST RELEASE: ADD QUOTE
• The Swing app will store the quotes in XML. DONE. The app will have the ability to transform this XML into HTML via XSLT. NOT DONE.

If anyone is interested, I'll post the final source code when I'm finished.

[/projects/quotes] permanent link