Converting JSON to XML w/o <n0>/<item0> - php

Question

I'm trying to convert xml to json back to xml for testing a service and I'm having an issue w/ repeated keys being represented incorrectly.
The following valid XML is the starting point:
<foo>
<bars>
<bar>
<url>http://url</url>
</bar>
<bar>
<url>http://url</url>
</bar>
</bars>
</foo>
Which converts to json:
{"bars":{"bar":[{"url":"http:\/\/url"},{"url":"http:\/\/url"}]}}
Every solution I've seen to similar questions ends up rendering the resulting xml as something like:
<bars>
<bar>
<n0>
<url>http://url</url>
</n0>
<n1>
<url>http://url</url>
</n1>
</bar>
</bars>
Obviously, I need to get back to the original xml. And the structure is quite complex and variable, so I can't count on a particular structure.
Any ideas?

Answer 1

I've done a few functions which encode and decode XML, the first takes an XML source as a SimpleXMLElement and converts it into an array (note that it doesn't deal with attributes) but seems to work for your test case and a few I've tried (the example has a slight modification to the XML to check). The second takes the same array and converts it into a string with the XML reconstructed. There is a lot of recursion going on but the routines are quite short so hopefully easy(ish) to follow...
function xmlToArray ( $base, SimpleXMLElement $node ) {
$nodeName = $node->getName();
$childNodes = $node->children();
if ( count($childNodes) == 0 ) {
$base[ $nodeName ] = (string)$node;
}
else {
$new = [];
foreach ( $childNodes as $newNode ) {
$new[] = xmlToArray($base, $newNode);
}
$base[$nodeName] = count($new)>1?$new:$new[0];
}
return $base;
}
function arrayToXML ( $base ) {
foreach ( $base as $name => $node ) {
$xml = "<{$name}>";
if ( $node instanceof stdClass ){
$xml .= arrayToXML($node);
}
elseif ( is_array($node) ) {
foreach ( $node as $ele ){
$xml .= arrayToXML($ele);
}
}
else {
$xml .= $node;
}
$xml .= "</{$name}>";
}
return $xml;
}
$xml_string = <<< XML
<foo>
<bars>
<bar>
<url>http://url1</url>
</bar>
<bar>
<url>http://url2</url>
</bar>
<url>http://url3</url>
</bars>
</foo>
XML;ToXML ($dec);
echo $target;
ML ($dec);
echo $target;
$source = simplexml_load_string($xml_string);
$xml = xmlToArray([], $source);
$enc = json_encode($xml);
echo $enc.PHP_EOL;
$dec = json_decode($enc);
$target = arrayToXML ($dec);
echo $target;
This outputs the JSON and the XML at the end as...
{"foo":{"bars":[{"bar":{"url":"http:\/\/url1"}},{"bar":{"url":"http:\/\/url2"}},{"url":"http:\/\/url3"}]}}
<foo><bars><bar><url>http://url1</url></bar><bar><url>http://url2</url></bar><url>http://url3</url></bars></foo>

Answer 2

You may use php file handling function and read xml file line by line or number of characters for fixed length tag name and using simple if conditions, print json string on a file.
This may work out.

Answer 3

There are many different ways of converting JSON to XML, or XML to JSON. They all work differently, and there is no single method that is always best. They all have to make some kind of compromise between usability and faithful round-tripping (for example, your library has dropped the outer "foo" element, which therefore can't be reconstituted on the reverse conversion).
You could devise a mapping of arbitrary XML to JSON that allows faithful round-tripping back to XML, but the JSON representation wouldn't be particularly user-friendly, especially for example if you need faithful round-tripping of namespaces.
XSLT 3.0 incidentally does the reverse: it has functions that will convert any JSON input losslessly to (a rather unfriendly vocabulary of) XML, and then convert the result faithfully back to the original JSON. You need the opposite of that.