Using form inputs in PHP to populate nested objects - php

Question

I am trying to process the submitted results for a form, containing data for a number of employees. The form inputs have names like "employees[1]_firstName" which needs to map to the PHP variable $companydata->employees[1]->firstName
When populating the $_POST array, PHP sees square brackets, and tries to make a multi-dimensional array, but gets it wrong (ignoring everything after the opening bracket)
This replicates $_POST but without the corrupted array keys: Note that I've taken out a foreach loop to simplify the question.
$post_data = explode('&', file_get_contents("php://input"));
// Result: $post_data = array('employees%5B1%5D_firstName=Timothy'
list($key, $value) = explode('=', $post_data[0]);
$key = urldecode($key);
$value = urldecode($value);
// Result: $key = 'employees[1]_firstName', $value = 'Timothy'
However things go wrong when I try to use variable variables:
$post_key_parts = explode('_', $key);
// Result: $post_key_parts = array([0] => 'employees[1]', [1] => 'firstName')
$Companydata->$post_key_parts[0]->$post_key_parts[1] = $value;
// Expected result: Element [0] in array $employees => 'Timothy'
The actual result is a variable with square brackets in its name '$employees[0]',
and no change to the $employees array. Putting curly brackets round the {$post_key_parts[0]} doesn't help.
I am trying to find a flexible solution that will also work for names of different lengths eg: employees[0]_address_lines[2] or employees[0]_addresses[1]_postcode
I'm happy to avoid the sin of variable variables, but I can't think of an elegant way to do it with regexes or something like that.

Answer 1

I would suggest you change the inputs' names. To make use of the built-in features of PHP. [] creates an array for you, use arrays then, as you are intended to use them.
I had the same problem and came up with this:
//HTML part
<input name="employee_firstName[]">
<input name="employee_address[]">
//PHP part
<?php
$info = array("firstName", "address")
foreach ($info as $i) {
foreach ($_POST["employee_".$i] as $k => $v) {
$companydata->employees[$k]->$i = $v;
}
}
?>
NOTE I don't think you can do this for things like employees[0]_address_lines[2]. Or maybe try employees[0][address_line][] and use it as an array, but I'm not sure that works.