<?xml version="1.0" encoding="UTF-8"?>
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<sect1 id="zend.json.xml2json">
    <title>XML to JSON conversion</title>
    <para>
        <classname>Zend_Json</classname> provides a convenience method for transforming
        <acronym>XML</acronym> formatted data into <acronym>JSON</acronym> format. This feature was inspired from an
        <ulink url="http://www.ibm.com/developerworks/xml/library/x-xml2jsonphp/">
        IBM developerWorks article</ulink>.
    </para>

    <para>
        <classname>Zend_Json</classname> includes a static function called <methodname>Zend_Json::fromXml()</methodname>.
        This function will generate <acronym>JSON</acronym> from a given <acronym>XML</acronym> input. This function takes any arbitrary
        <acronym>XML</acronym> string as an input parameter. It also takes an optional boolean input parameter to instruct the
        conversion logic to ignore or not ignore the <acronym>XML</acronym> attributes during the conversion process. If this
        optional input parameter is not given, then the default behavior is to ignore the <acronym>XML</acronym> attributes.
        This function call is made as shown below:
    </para>
    <programlisting language="php"><![CDATA[
// fromXml function simply takes a String containing XML contents
// as input.
$jsonContents = Zend_Json::fromXml($xmlStringContents, true);
]]></programlisting>

    <para>
        <methodname>Zend_Json::fromXml()</methodname> function does the conversion of the <acronym>XML</acronym> formatted string input
        parameter and returns the equivalent <acronym>JSON</acronym> formatted string output. In case of any <acronym>XML</acronym> input format
        error or conversion logic error, this function will throw an exception. The conversion logic also
        uses recursive techniques to traverse the <acronym>XML</acronym> tree. It supports recursion upto 25 levels deep.
        Beyond that depth, it will throw a <classname>Zend_Json_Exception</classname>. There are several <acronym>XML</acronym> files with varying
        degree of complexity provided in the tests directory of Zend Framework. They can be used to
        test the functionality of the xml2json feature.
    </para>

    <para>
        The following is a simple example that shows both the <acronym>XML</acronym> input string passed to
        and the <acronym>JSON</acronym> output string returned as a result from the
        <methodname>Zend_Json::fromXml()</methodname> function. This example used the optional function parameter as
        not to ignore the <acronym>XML</acronym> attributes during the conversion. Hence, you can notice that the
        resulting <acronym>JSON</acronym> string includes a representation of the <acronym>XML</acronym> attributes present in the <acronym>XML</acronym> input string.
    </para>

    <para>
        <acronym>XML</acronym> input string passed to <methodname>Zend_Json::fromXml()</methodname> function:
    </para>

    <programlisting language="php"><![CDATA[
<?xml version="1.0" encoding="UTF-8"?>
<books>
    <book id="1">
        <title>Code Generation in Action</title>
        <author><first>Jack</first><last>Herrington</last></author>
        <publisher>Manning</publisher>
    </book>

    <book id="2">
        <title>PHP Hacks</title>
        <author><first>Jack</first><last>Herrington</last></author>
        <publisher>O'Reilly</publisher>
    </book>

    <book id="3">
        <title>Podcasting Hacks</title>
        <author><first>Jack</first><last>Herrington</last></author>
        <publisher>O'Reilly</publisher>
    </book>
</books>
]]></programlisting>

    <para>
        <acronym>JSON</acronym> output string returned from <methodname>Zend_Json::fromXml()</methodname> function:
    </para>

    <programlisting language="php"><![CDATA[
{
   "books" : {
      "book" : [ {
         "@attributes" : {
            "id" : "1"
         },
         "title" : "Code Generation in Action",
         "author" : {
            "first" : "Jack", "last" : "Herrington"
         },
         "publisher" : "Manning"
      }, {
         "@attributes" : {
            "id" : "2"
         },
         "title" : "PHP Hacks", "author" : {
            "first" : "Jack", "last" : "Herrington"
         },
         "publisher" : "O'Reilly"
      }, {
         "@attributes" : {
            "id" : "3"
         },
         "title" : "Podcasting Hacks", "author" : {
            "first" : "Jack", "last" : "Herrington"
         },
         "publisher" : "O'Reilly"
      }
   ]}
}
]]></programlisting>

    <para>
        More details about this xml2json feature can be found in the original proposal itself.
        Take a look at the
        <ulink url="http://tinyurl.com/2tfa8z">Zend_xml2json proposal</ulink>.
    </para>

</sect1>
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