Converts json to csv. If json is multidimensional - serializing it

json2csv.php

<?php
/*
Plugin Name: json2csv
Description: Converts json to csv. If json is multidimensional - serializing it
Usage: Example is below code
Version: 0.1
Author: Lomboboo 
*/

class JSON2CSV {
	private $jsonFilename;
	private $csv;

	function __construct($jsonFilename, $csvName = null)
	{
		$this->jsonFilename = $jsonFilename;

		$this->csv = fopen($csvName ? $csvName.'.csv' : $jsonFilename.'.csv', 'w') or die("Unable to open file!");
	}

	public function convert() {
		$json = file_get_contents($this->jsonFilename . '.json');
		$array = json_decode($json, true);
		$keys = array();

// collect keys
		foreach($array as $line){
			foreach($line as $key => $value){
				if(!in_array($key, $keys))
					$keys[] = $key;
			}
		}

		$keyString = implode(",", $keys);
		fwrite($this->csv, "$keyString\n"); // writing header to csv

		foreach ($array as $line)
		{
			$outputArray = array();
			foreach($keys as $key){

				if(array_key_exists($key, $line)){

					if ( is_array($line[$key]) ) { // if key value is array - serialize it
						$s = serialize($line[$key]);
						$outputArray[] = str_replace(',', '', $s);
					} else {
						$outputArray[] = str_replace(',', '', str_replace("\r\n",'', $line[$key]));
					}

				} else {
					$outputArray[] = "";
				}
			}

			$outputString = implode(",", $outputArray);
			fwrite($this->csv, "$outputString\n");
		}

		fclose($this->csv);
	}
}

// example
$json1 = new JSON2CSV('file', 'csv'); // second parameter is csv output name | optional | default is json name

$json1->convert();