This is an experiment in using Erlang lists to represent XML and XHTML.

1> XMList = [foo, [bar]].
[foo,[bar]]
2> io:format(xmlists:render(XMList)).
<foo><bar /></foo>

Examples

[table,
    [tr,
        [td, "foo"],
        [td, "bar"],
        [td, [{class, numeric}], 4711]]]

Becomes:

<table>
    <tr>
        <td>foo</td>
        <td>bar</td>
        <td class="numeric">4711</td>
    </tr>
</table>

(Except without the line-breaks and indentation)

Since they are just ordinary lists, you can construct them however you want. For example using a list comprehension:

[ul,
    [[li, N] || N <- [1,2,3]]]

Becomes:

<ul>
    <li>1</li>
    <li>2</li>
    <li>3</li>
</ul>

The rules

1. A list starting with an atom is an XML element.

    [foo] -> <foo />
   

2. Anything following that first atom is the content of the element.

    [foo, "bar"] -> <foo>bar</foo>
   

3. The exception from rule 2 is that a list with tuples directly following that first atom holds attributes.

    [foo, [{id, 4711}], "bar"] -> <foo id="4711">bar</foo>
   

4. The content can be strings, binaries, atoms or numbers.

    [foo, bar]       -> <foo>bar</foo>
    [foo, "bar"]     -> <foo>bar</foo>
    [foo, <<"bar">>] -> <foo>bar</foo>
    [foo, 4711]      -> <foo>4711</foo>
   

5. Multiple contents are concatenated together.

    [p, "bar", "baz", [span, "ooka"]] -> <p>barbaz<span>ooka</span></p>
   

Exported functions

XML

xmlists:render(List)          -> iolist()
xmlists:render(List, Options) -> iolist()

Options = [{encoding, Encoding}]

Converts an "xmlist" to a string (iolist). If Encoding (e.g "UTF-8") is specified the output is preceded by an XML declaration element. For now, that is the only thing the encoding option does.

HTML

htmlists:render(List)          -> iolist()
htmlists:render(List, Options) -> iolist()

Options = [{encoding, Encoding} | {doctype, DocType}]
DocType = strict | transitional | frameset | html5

A thin wrapper around xmlists that can optionally preceded the output with a doctype and wrap the content in an html root element.

It also knows which empty HTML elements are valid to self-close. For example:

[br] -> <br />
[p]  -> <p></p>

Output

The output is an iolist, which looks messy in itself.

1> XMList = [foo, [bar]].
[foo,[bar]]
2> xmlists:render(XMList).
[[60,"foo",[],62],[[60,"bar",[],32,47,62]],60,47,"foo",62]

But most functions that write output to the screen, files or sockets will take an iolist as input.

3> io:format(xmlists:render(XMList)).
<foo><bar /></foo>