Can't access upload file input with php - php

Question

I created a simple form, to create a post, that has three inputs:
One for the title
Description
Image
So, when I submit my form (using post) I call a php file, that "echoes" the value from each input.
It works just fine, but when I try to call the php function $_FILES['my_input_name']['tmp_name'], on my file input, I get an error saying:
Undefined index: my_input_name
My form looks like this (shorter version):
<form action="processForm.php" method="post">
<input type="text" name="title" class="input" required>
<textarea id="description" name="description"required></textarea>
<input type="file" name="fileMedia">
</form>
My php file looks like this
$method = $_SERVER[ 'REQUEST_METHOD' ];
if ( $method=='POST') {
$_args = $_POST;
$_INPUT_METHOD = INPUT_POST;
}
elseif ( $method=='GET' ) {
$_args = $_GET;
$_INPUT_METHOD = INPUT_GET;
}
else {
exit(-1);
}
$title = $_args['title'];
$description = $_args['description'];
$mediaName = $_args['fileMedia'];
$mediatmpPath = $_FILES["fileMedia"]["tmp_name"];
echo $title."<br>";
echo $description."<br>";
echo $mediaName."<br>";
echo $mediatmpPath ."<br>";
I have no idea of what I'm doing wrong, so any helped would be really apreciated!
P.s: My form's is really reduced. In the original one I have row, cols, divs, etc, and some other inputs, which I did not find relevant for this question

Answer 1

You just need to add multipart = "form/data" in form tag

Answer 2

You need to add this below line in <form> tag
<form action="processForm.php" method="post" enctype='multipart/form-data'>
<input type="text" name="title" class="input" required>
<textarea id="description" name="description"required></textarea>
<input type="file" name="fileMedia">
<input type="submit" name="save" value="save">
</form>
And below post data code:
<?php $method = $_SERVER[ 'REQUEST_METHOD' ];
if ( $method=='POST') {
$_args = $_POST;
$_INPUT_METHOD = INPUT_POST;
}
elseif ( $method=='GET' ) {
$_args = $_GET;
$_INPUT_METHOD = INPUT_GET;
}
else {
exit(-1);
}
$title = $_args['title'];
$description = $_args['description'];
$mediaName = $_FILES["fileMedia"]["name"];
$mediatmpPath = $_FILES["fileMedia"]["tmp_name"];
echo $title."<br>";
echo $description."<br>";
echo $mediaName."<br>";
echo $mediatmpPath ."<br>";
?>
I think this help you.