XML depth/previousDepth are not correctly handled

[FunkyOz]

Hi everyone,
I think that XML depth is not correctly handled and xml adapter does not work properly.

If you use a deep xml scructure like this:

<?xml version="1.0" encoding="utf-8"?>
<root>
    <cars>
        <car>
            <model>
                <make>Mercedes</make>
            </model>
        </car>
        <car>
            <model>
                <make>BMW</make>
            </model>
        </car>
        <car>
            <model>
                <make>Nissan</make>
            </model>
        </car>
    </cars>
</root>

And run process

(new Flow())
    ->read(XML::from($filepath, 'root/cars/car'))
    ->write(\Flow\ETL\DSL\To::output(false))
    ->run();

The result is

+----------------------------------------------------------------------------------------------------------------------+
|                                                                                                                 node |
+----------------------------------------------------------------------------------------------------------------------+
| <?xml version="1.0"?><car>            <model>                <make>Mercedes</make>            </model>        </car> |
+----------------------------------------------------------------------------------------------------------------------+

But I expect this output

+----------------------------------------------------------------------------------------------------------------------+
|                                                                                                                 node |
+----------------------------------------------------------------------------------------------------------------------+
| <?xml version="1.0"?><car>            <model>                <make>Mercedes</make>            </model>        </car> |
|      <?xml version="1.0"?><car>            <model>                <make>BMW</make>            </model>        </car> |
|   <?xml version="1.0"?><car>            <model>                <make>Nissan</make>            </model>        </car> |
+----------------------------------------------------------------------------------------------------------------------+

Maybe I'm wrong and I don't understand the intent behind this adapter but I think that internally he does not correctly handle the depth/previous depth.

Look at XMLReaderExtractor::extract at line 60 and supposed to be in depth 4 (meaning <make> tag, the deepest tag found).

In the next iteration previousDepth=4 and and depth=2 (meaning <car>, because reader back up to parent).
So the only entered if statement is $xmlReadler->depth < $previousDepth and \array_pop($currentPathBreadCrumbs) line was executed.

So now $currentPathBreadCrumbs is ['root', 'cars', 'car', 'model'] but is not the correct path (remember that reader back up to <car>).

I expect that in case of $depth < $previousDepth we should be remove all tags with depth between $xmlReadler->depth and $previousDepth and in this specific case $currentPathBreadCrumbs should be ['root', 'cars', 'car'].

Thanks, I hope I was clear :)