parse multi-dimensional form-data from PATCH request

parse_raw_http_request.php

<?php

// The code is inspired by the following discussions and post:
// http://stackoverflow.com/questions/5483851/manually-parse-raw-http-data-with-php/5488449#5488449
// http://www.chlab.ch/blog/archives/webdevelopment/manually-parse-raw-http-data-php

/**
 * Parse raw HTTP request data
 *
 * Pass in $a_data as an array. This is done by reference to avoid copying
 * the data around too much.
 *
 * Any files found in the request will be added by their field name to the
 * $data['files'] array.
 *
 * @param   array  Empty array to fill with data
 * @return  array  Associative array of request data
 */
function parse_raw_http_request($a_data = [])
{
    // read incoming data
    $input = file_get_contents('php://input');

    // grab multipart boundary from content type header
    preg_match('/boundary=(.*)$/', $_SERVER['CONTENT_TYPE'], $matches);

    // content type is probably regular form-encoded
    if (!count($matches))
    {
        // we expect regular puts to containt a query string containing data
        parse_str(urldecode($input), $a_data);
        return $a_data;
    }

    $boundary = $matches[1];

    // split content by boundary and get rid of last -- element
    $a_blocks = preg_split("/-+$boundary/", $input);
    array_pop($a_blocks);

    $keyValueStr = '';
    // loop data blocks
    foreach ($a_blocks as $id => $block)
    {
        if (empty($block))
            continue;

        // you'll have to var_dump $block to understand this and maybe replace \n or \r with a visibile char

        // parse uploaded files
        if (strpos($block, 'application/octet-stream') !== FALSE)
        {
            // match "name", then everything after "stream" (optional) except for prepending newlines
            preg_match("/name=\"([^\"]*)\".*stream[\n|\r]+([^\n\r].*)?$/s", $block, $matches);
            $a_data['files'][$matches[1]] = $matches[2];
        }
        // parse all other fields
        else
        {
            // match "name" and optional value in between newline sequences
            preg_match('/name=\"([^\"]*)\"[\n|\r]+([^\n\r].*)?\r$/s', $block, $matches);
            $keyValueStr .= $matches[1]."=".$matches[2]."&";
        }
    }
    $keyValueArr = [];
    parse_str($keyValueStr, $keyValueArr);
    return array_merge($a_data, $keyValueArr);
}