Passing an array to another page (Form) - php

Question

I have the following array and form on page1.php:
$my_array = array("Volvo", "BMW", "Toyota");
echo " <form id=\"my_form\" action=\"page2.php\" method=\"post\" enctype=\"multipart/form-data\">
<input type=\"hidden\" name=\"id\" value=\"10\">
<input type=\"hidden\" name=\"input_name\" value=\"".serialize($my_array)."\" />
Send </form>";
On the page2.php I want to print_r the array:
$id = $_POST['id'];
$passed_array = unserialize($_POST['input_name']);
print_r($passed_array);
Why I can't receive my_array on page2? I can't see the mistake I made!
PS: I received id on page2.

Answer 1

i'm glad #ksealey pointed out a more proper method of doing this, but for the sake of answering the question...the reason it's not working is that the serialize alone is not enough to prevent the invalid html. see result of what the serialize leaves in the html:
so you need to be sure the html you produce is valid. you might use encoding like base64 to produce safe html:
echo " <form id=\"my_form\" action=\"\" method=\"post\"";
echo "enctype=\"multipart/form-data\">";
echo "<input type=\"hidden\" name=\"id\" value=\"10\">";
echo "<input type=\"hidden\" name=\"input_name\" ";
echo "value=\"".base64_encode(serialize($my_array))."\" />";
then you can just add the decode to your output:
$passed_array = unserialize(base64_decode($_POST['input_name']));
print_r($passed_array);

Answer 2

If there is data to be passed from page to page use a session
<?php
//Page 1
session_start();
$value = 'Value from page 1';
$_SESSION['page_1_value'] = $value;
?>
<?php
//Page 2
session_start();
echo 'Value from page 1: '.$_SESSION['page_1_value'];
$_SESSION = array(); //If you want to wipe the session data after
OR, pass as value params that get cleaned, JSON object maybe?
<form id="my_form" action="page2.php" method="post" enctype="multipart/form-data">
<input type="hidden" name="id" value="10">
<input type="hidden" name="input_name" value="<?php echo json_encode($my_array); ?>" />
<a href="javascript:{}" onclick="document.getElementById('my_form').submit(); return false;">Send</a
</form>
<?php
//Page 2
$object = json_decode(strip_tags(stripslashes($_POST['input_name'])));
var_dump($object);
I will say the first answer is safer.

Answer 3

This is the HTML that your first page is generating:
<input type="hidden" name="input_name" value="a:3:{i:0;s:5:" volvo";i:1;s:3:"bmw";i:2;s:6:"toyota";}"="">
One easy solution would be to replace your double quotes in
value=\"".serialize($my_array)."\"
with single quotes as so:
value='" . serialize($my_array) . "'
or you can escape the quotes in your serialized array as so:
value=\"". htmlspecialchars(serialize($my_array))."\"

Answer 4

I will just add my 2 cents in here :)
You may want to use a framework of some sort as this will ease the job for you a lot with situations like this (or similar). For example with Codeigniter framework you could have a form (view) that sends data to controller and in controller you could just grab the whole array as so:
$data = $this->input->post('array');
$data[0] should == 'Volvo'
So view:
<?php $my_array = array("Volvo", "BMW", "Toyota"); ?>
<form id="my_form" action="<?php echo site_url(controller_name/controller_function)" method="post" enctype="multipart/form-data">
<input type="hidden" name="id" value="10">
<input type="hidden" name="input_name" value="".serialize($my_array)."" />
Controller:
public function foo() {
$data = $this->input->post('array');
for($i=0; $i<sizeof($data); $i++) {
echo $data[$i];
}
}