xmlwriter.d

import std.xml;
import std.string;
import std.container.stack;

class XmlWriter
{
    this()
    {
        m_stack = new Stack!Element();
    }

    void writeStartDocument()
    {
    }

    void writeDefaultNamespace(in string value)
    {
        if (m_element)
        {
            writeAttribute("xmlns", value);
        }
        else
        {
            m_namespace = value;
        }
    }

    void writeStartElement(in string name)
    {
        if (!m_element)
        {
            m_element = new Document(new Tag(name));
            if (m_namespace)
                writeAttribute("xmlns", m_namespace);
        }
        else
        {
            m_stack.push(m_element);
            m_element = new Element(name);
        }
    }

    void writeAttribute(in string name, in string value)
    {
        m_element.tag.attr[name] = value;
    }

    void writeTextElement(in string name, in string value)
    {
        m_stack.push(m_element);
        m_element = new Element(name, value);
        writeEndElement();
    }

    void writeEndElement()
    {
        if (!m_stack.empty)
        {
            auto parent = m_stack.pop();
            parent ~= m_element;
            m_element = parent;
        }
    }

    void writeEndDocument()
    {
    }

    override string toString()
    {
        if (!m_autoformatting)
            return m_element.toString();
        return join(m_element.pretty(m_indent), "\n");
    }

    @property autoFormatting(in bool value)
    {
        m_autoformatting = value;
    }

    @property autoFormattingIndent(in int value)
    {
        m_indent = value;
    }

private:
    bool m_autoformatting;
    int m_indent = 4;
    string m_namespace;
    Element m_element;
    Stack!Element m_stack;

    unittest
    {
        {
            auto xml = new XmlWriter();
            xml.writeStartDocument();
            xml.writeDefaultNamespace("http://example.com");
            xml.writeStartElement("Root");
            xml.writeEndElement();
            xml.writeEndDocument();

            assert(xml.toString() == "<?xml version=\"1.0\"?><Root xmlns=\"http://example.com\" />");
        }

        {
            auto xml = new XmlWriter();
            xml.writeStartDocument();
            xml.writeStartElement("Root");
            xml.writeDefaultNamespace("http://example.com");
            xml.writeEndElement();
            xml.writeEndDocument();

            assert(xml.toString() == "<?xml version=\"1.0\"?><Root xmlns=\"http://example.com\" />");
        }

        {
            auto xml = new XmlWriter();
            xml.writeStartDocument();
            xml.writeStartElement("Root");
            xml.writeAttribute("xmlns", "http://example.com");
            xml.writeEndElement();
            xml.writeEndDocument();

            assert(xml.toString() == "<?xml version=\"1.0\"?><Root xmlns=\"http://example.com\" />");
        }

        {
            auto xml = new XmlWriter();
            xml.writeStartDocument();
            xml.writeStartElement("Root");
            xml.writeStartElement("Child1");
            xml.writeTextElement("SubChild1", "Foo");
            xml.writeEndElement();
            xml.writeStartElement("Child2");
            xml.writeAttribute("simple", "easy");
            xml.writeEndElement();
            xml.writeStartElement("Child3");
            xml.writeAttribute("simple", "easy");
            xml.writeEndElement();

            xml.writeEndElement();
            xml.writeEndDocument();

            assert(xml.toString() == "<?xml version=\"1.0\"?><Root><Child1><SubChild1>Foo</SubChild1></Child1><Child2 simple=\"easy\" /><Child3 simple=\"easy\" /></Root>");
        }
    }
}