Need help writing and reading a file with PHP - php

Question

So for an assignment, I have to create a form where users can post ride shares so other people can see and join their ride. I'm doing this by writing the form to a file data.txt, and reading the file to display all the rides on a board. My only problem is when I get the contents of data.txt, it's all combined together. I need to be able to display each ride separately. How would I go about doing this?
Here is my code so far:
The writing:
if (isset($_POST['name'])
&& isset($_POST['email'])
&& isset($_POST['date'])
&& isset($_POST['destination'])
&& isset($_POST['msg'])) {
$name = $_POST['name'];
$email = $_POST['email'];
$date = $_POST['date'];
$destination = $_POST['destination'];
$msg = $_POST['msg'];
//TODO the file write here VV, use 'a' instead of 'w' too ADD to the file instead of REWRITING IT.
$arr = [$name,$email,$date,$destination,$msg];
$write = json_encode($arr);
$file = fopen('data.txt', 'a');
fwrite($file, $write);
fclose($file);
}
And the reading:
$path = 'data.txt';
$handle = fopen($path, 'r');
$contents = fread($handle, filesize($path));
echo $contents;
fclose($handle);
$newarr = [json_decode($contents)];
foreach($newarr as $stuff)
{
echo $stuff[0];
}
And the output is something like:
["Simon Long","example#gmail.com","2109-01-01T01:01","canada","this is a message"] Simon Long
Let's say there are multiple postings in there, it would just print them all together. I need a way to separate postings so I can display them nicely on the board.

Answer 1

Use a multidimensional array.
$arr = [
"Simon Long","example#gmail.com","2109-01-01T01:01","canada","this is a message",
"John Doe","john#gmail.com","2109-01-01T01:01","canada","this is a message",
"Jane Doe","jane#gmail.com","2109-01-01T01:01","canada","this is a message"
];
Then you when you add to it just append to the final array and replace the whole file.
$contents = file_get_contents($path);
$decoded = json_decode($contents);
$decoded[] = [$name,$email,$date,$destination,$msg];
file_put_contents($path, json_encode($decoded)); //replace the entire file.
Also just as a side note. isset accepts multiple arguments so you don't need to use it as you are. You can do this:
if (isset($_POST['name'], $_POST['email'], $_POST['date'], $_POST['destination'] ...)
It's also a good idea to sanitise any input from the user.
$name = filter_input(INPUT_POST, 'name', FILTER_SANITIZE_STRING);