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<h2><a name="introduction"></a>Introduction</h2>

<p>Lua Object Model (LOM) is a representation of XML elements
through Lua data types. Currently it is not supposed to be 100%
complete, but simple.</p>

<p>LuaExpat's distribution provides an implementation of LOM that
gets an XML documenta (a string) and transforms it to a Lua table.
The only function exported is <strong><code>lxp.lom.parse</code></strong>.</p>

 
<h2><a name="characteristics"></a>Characteristics</h2>

<p>The model represents each XML element as a Lua table. A LOM
table has three special characteristics:</p>

<ul>
    <li>a special field called <strong><code>tag</code></strong> that holds the
    element's name;</li>

    <li>an optional field called <strong><code>attr</code></strong> that stores
    the element's attributes (see <a href="#attributes">attribute's
    section</a>); and</li>
    
    <li>the element's children are stored at the <em>array-part</em> of
    the table. A child could be an ordinary string or another XML
    element that will be represented by a Lua table following these
    same rules.</li>
</ul>


<h3><a name="attributes"></a>Attributes</h3>

<p>The special field <strong><code>attr</code></strong> is a Lua table that
stores the XML element's attributes as pairs
<em>&lt;key&gt;=&lt;value&gt;</em>. To assure an order (if
necessary), the sequence of <em>key</em>s could be placed at the
<em>array-part</em> of this same table.</p>


<h2><a name="examples"></a>Examples</h2>

<p>For a simple string like</p>

<pre class="example">
    s = [[&lt;abc a1="A1" a2="A2"&gt;inside tag `abc'&lt;/abc&gt;]]
</pre>

<p>A call like</p>

<pre class="example">
    tab = lxp.lom.parse (s))
</pre>

<p>Would result in a table equivalent to</p>

<pre class="example">
tab = {
        ["attr"] = {
                [1] = "a1",
                [2] = "a2",
                ["a2"] = "A2",
                ["a1"] = "A1",
        },
        [1] = "inside tag `abc'",
        ["tag"] = "abc",
}
</pre>

<p>Now an example with an element nested inside another element</p>

<pre class="example">
tab = lxp.lom.parse(
[[&lt;qwerty q1="q1" q2="q2"&gt;
    &lt;asdf&gt;some text&lt;/asdf&gt;
&lt;/qwerty&gt;]]
)
</pre>

<p>The result would have been a table equivalent to</p>

<pre class="example">
tab = {
        [1] = "\
        ",
        [2] = {
                ["attr"] = {
                },
                [1] = "some text",
                ["tag"] = "asdf",
        },
        ["attr"] = {
                [1] = "q1",
                [2] = "q2",
                ["q2"] = "q2",
                ["q1"] = "q1",
        },
        [3] = "\
",
        ["tag"] = "qwerty",
}
</pre>

<p>Note that even the <em>new-line</em> and <em>tab</em> characters are stored 
on the table.</p>

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