Convert a list of json strings to csv in PHP

json2csv.php

<?php

/*

author: Guillermo <yo@guilles.website>

This converst a list of jsons to a csv string. JSON names 
are built with the key names and points. See example below.
It basically flattens associative arrays with a recursive function
and then merges all these flattened arrays.
*/

function jsonListToCSV ($jsonList) {
    function  procArray(&$input, &$output, $path) {
        foreach ($input as $key => $val) {
            if (is_array($val)) {
                procArray($input[$key], $output, empty($path) ? $key : $path.".".$key);
            }
            else {
                $output[empty($path)? $key : $path.".".$key] = $val;
            }
        }
    }

    $flatDatas = array();
    $keys = array();
  
    foreach ($jsonList as $record) {
        $data = json_decode($record, TRUE);
        $flatData = array();
        procArray($data, $flatData, "");
        array_push($flatDatas, $flatData);
        $keys = array_merge($keys, array_diff(array_keys($flatData), $keys));
    }
    sort($keys, SORT_STRING);

    $csvoutput = implode(",", $keys)."\n\r";;
    $nkeys = count($keys);
    foreach ($flatDatas as $flatData) {
        $i = 0;
        foreach($keys as $key) {
            $i++;
            if (isset($flatData[$key])) {
                $csvoutput .= "\"".addslashes($flatData[$key])."\"";
            }
            else  {
                $csvoutput .= "";
            }
            if ($i < $nkeys) 
                $csvoutput .= ",";
        }
        $csvoutput .= "\n\r";

    }
    return $csvoutput;
}

/*

EXAMPLE:

echo jsonListToCSV(array(
  '{ "a": 1, "b": { "c": 2, "d": [3,4,5,6] } }', 
  '{ "a": 5, "b": { "c": 6, "d": [7,8] }, "f": [ {"g": 9}, {"h": 10} ] }', 
  '{ "b": { "c": 7, "d": [9,10,11] }, "f": [ {"g": 9}, {"g": 10} ] }', 
  '{ "a": 6, "b": { "c": 8, "d": [72,18] }, "f": [ {"g": 19}, {"g": 15} ] }', 
  '{ "a": 7, "b": { "c": 9, "d": [17,98,10] }, "f": [ {"g": 92}, {"h": 1} ] }', 
));


OUTPUT:

a,b.c,b.d.0,b.d.1,b.d.2,b.d.3,f.0.g,f.1.g,f.1.h
"1","2","3","4","5","6",,,
"5","6","7","8",,,"9",,"10"
,"7","9","10","11",,"9","10",
"6","8","72","18",,,"19","15",
"7","9","17","98","10",,"92",,"1"

*/