Trouble using $_POST across files with XAMPP - php

Question

I want to process form input into a MYSQL database but I am having trouble getting other files to recognize data in the _POST array and keep getting the typical "Undefined index" error.
My form:
<?php
$category = '';
$item = '';
// Check if form is posted
if (isset($_POST['item'])){
// Declare POST'd values into variables
$category = $_POST['Category'];
$item = $_POST['item'];
}
?>
<!-- Item Input form -->
<form id='additem' method='post' action="">
<fieldset>
<legend>Add Item</legend>
<table>
<tr>
<td><label for='Category'>Category: </label></td>
<td><input type='text' name='Category' list='categories' value='<?php $category;?>' /></td>
<datalist id='categories'>
<option value='Protein'>
<option value='Produce'>
<option value='Baked Goods'>
<option value='Dry/Canned'>
<option value='Household'>
</datalist>
</tr><tr>
<td><label for='item'>Name: </label></td>
<td><input type='text' name='item' value='<?php $item;?>' /></td>
</tr><tr>
<td></td><td><input type='Submit' value='Submit' /></td>
</tr>
</table>
</fieldset>
</form>
When I use $_POST in this file, it works perfectly fine but when I try to use it in another file, process.php:
<?php
echo $_POST['Category'];
echo '<br>';
echo $_POST['item'];
?>
it gives:
Notice: Undefined index: Category in E:\Documents\XAMPP\htdocs\Website\process.php on line 3
Notice: Undefined index: item in E:\Documents\XAMPP\htdocs\Website\process.php on line 5
Now I know my _POST array is not empty, because I can access it within my original form file. If I change the form action to "process.php" it works, but also automatically takes me to that page. What I want is for process.php to send data to my database while the form returns to its own page ready for more input. I have even literally copy and pasted the code from that example into files and attempted to run those, but I get similar errors so I think it might be an issue with XAMPP/Apache.
To address this, I have also tried this but post_max_size was already set to 8M, and as per another post I saw somewhere I added 'variables_order = "EGPCS"' in the line below. Still I am getting the same undefined index.
Is there something wrong with my code? Is it XAMPP/Apache? I have tried fresh installing XAMPP, but the issue still persists.

Answer 1

Your $_POST array will not be accessible on all pages.
As much as I have understood your problem , You are trying to access $_POST array on some other file , and this can only be used in this file or the file you post to.
You need to use SESSION in order to use these values
After POST Assign your values like this
$_SESSION["Category"] = $_POST['Category'];
Then on any other page just use
session_start(); on the top of page and then print your variable like
echo "Selected Category is " . $_SESSION["Category"] . ".<br>";

Answer 2

You have not specified the location or file in the action attribute of form element. The file specified in the action attribute can have the values of the form in &_POST[] global array. To access the values across multiple page you should use the cookies

Answer 3

Put check on
category
as you are only checking the
item
in array and if category is not present in array then it will give undefined index error so try the following ways
$category = '';
$item = '';
if (isset($_POST['item']) && isset($_POST['Category'])){
// Declare POST'd values into variables
$category = $_POST['Category'];
$item = $_POST['item'];
}
or if you want you can check them in different conditions
$category = '';
$item = '';
if (isset($_POST['item'])){
// Declare POST'd values into variables
$item = $_POST['item'];
}
if (isset($_POST['Category'])){
// Declare POST'd values into variables
$category = $_POST['Category'];
}