'appending' associative array with duplicate keys to multidimensional associative array - php

Question

For a client, I'm building a link between the client's application and a third party's application. The third party's application expects fields like below:
<General>
<Signing>
<Signing>
<FieldA></FieldA>
<FieldB></FieldB>
<FieldC></FieldC>
</Signing>
<Signing>
<FieldA></FieldA>
<FieldB></FieldB>
<FieldC></FieldC>
</Signing>
</Signing>
</General>
We're building the input for the link in PHP, by means of a multi-dimensional associative array. So the above XML would compute to the following PHP:
'General' => array(
'Signing' => array(
'Signing' => array(
'FieldA' => '',
'FieldB' => '',
'FieldC' => ''
),
'Signing' => array(
'FieldA' => '',
'FieldB' => '',
'FieldC' => ''
)
)
)
There's a few problems.
There's no such thing as duplicate keys in an associative array. The output would be messed up.
The third party NEEDS it like this, this is just how they set up their application.
Even if there was such a thing as duplicate kets in an associative array, there is no way that would outputto what the third party expects. The Signing would just be overwritten with the last Signing item.
My question is, how do I make a dynamic associative array (so the number of Signings can vary) with duplicate Signing keys that still outputs every instance of Signing, instead of just one Signingfield with just the last instance.
I hope this makes sense. I'm foreign and my brain is chaos so I'm terrible at explaining things.
Thanks in advance!

Answer 1

You cannot express the same data structure literally in PHP, period. You'll have to express it differently and your XML-serialiser will have to translate appropriately between the PHP array structure and the expected XML representation. A sensible PHP array structure would be this:
'General' => array(
'Signing' => array(
array('FieldA' => '', 'FieldB' => '', 'FieldC' => ''),
array('FieldA' => '', 'FieldB' => '', 'FieldC' => ''),
)
)
The XML serialiser would do something akin to:
foreach ($array['General']['Signing'] as $signing) {
$xml->General->Signing->appendChild('Signing')
..
}
How exactly to do this depends on your XML serialisation process. Suffice it to say that the data structure doesn't need to be/can't be literally identical and will require a translation layer.