Xml::arrayToXml fails on nested arrays

從 Xml::arrayToXml helper 開始，重現 issue 中的巢狀陣列範例。檢查巢狀元素在存在之前就被傳入的遞迴分支，然後驗證該範例是否能在沒有 PHP 錯誤的情況下產生預期的巢狀 XML。

The helper function arrayToXml has code indended to handle nested arrays, but currently always throws PHP errors. This means nested arrays can't be used when testing soap functions with array data either.

Reproduce

Code:

$dom = new \DOMDocument();
$array = [
    'foo' => [
        'bar' => '1'
    ]
];
echo \Codeception\Util\Xml::arrayToXml($dom, $dom, $array)->saveXML();

Expected output:

<?xml version="1.0"?>
<foo><bar>1</bar></foo>

Result:

Undefined property: DOMDocument::$foo

Cause

When the function encounters an array, it calls itself to parse the array, with $domNode->$el as the new $domNode parameter. The problem is that that node ->$el will never exist, since that's the node this function was supposed to create in the first place.

Fix

Create a new element first, to pass to the recursive call, and then append that new node to the xml structure.

Current code:

            if (is_array($val)) {
                self::arrayToXml($xml, $domNode->$el, $val);
            } else {
                $domNode->appendChild($xml->createElement($el, $val));
            }

Fixed code:

            if (is_array($val)) {
                $elementNode = $xml->createElement($el);
                self::arrayToXml($xml, $elementNode, $val);
                $domNode->appendChild($elementNode);
            } else {
                $domNode->appendChild($xml->createElement($el, $val));
            }

Alternatively, we could make it a little more consistent by always creating and appending the element in the same way, and only set the value inside the if-condition. That code would look like this:

            $elementNode = $xml->createElement($el);
            if (is_array($val)) {
                self::arrayToXml($xml, $elementNode, $val);
            } else {
                $elementNode->nodeValue = $val;
            }
            $domNode->appendChild($elementNode);

Both solutions result in working code for nested arrays.