Do query strings need to be manually sent to POST requests - php

Question

This is a CakePHP / General PHP question.
In my application I use a query string like /login?continue=/admin/posts
This query string is used to redirect users to the URL in the query, but it doesn't work so it seems as though the app can't see the string...
This has got me wondering as basically when you arrive at the page with the string it's a GET request where as when you login, it becomes a POST or XML request (if using AJAX). Do I need to add the query string manually to the form for the POST to see it?
Either in the form action or a hidden input? Or am I barking up the wrong tree?
I'm currently grabbing the query like so:
if(isset($this->params['url']['continue']))
{
$pathtoredirect = $this->params['url']['continue'];
}
else
{
$pathtoredirect = $this->Auth->redirect();
}
But that's within the POST request so perhaps the query is lost... and adding it to a hidden input would not solve the problem with the current code so I would either change the code to look at the hidden field or pass the query with the action on the form?
e.g. <form action="/login?continue=/admin/posts" method="post">
Am I correct in thinking this? And would anyone be able to offer solutions or pros and cons of the two methods I mention?
In short I'm asking how to add the query string to my form action value
It currently looks like:
php echo $this->Form->create('User',
array(
'id' => 'loginform',
'type' => 'post',
'url' => array
(
'admin'=>false,
'controller' => 'users',
'action' => 'login'
)
)
);
So how would I add the query string to the form?
Thanks

Answer 1

When receiving a POST request you can receive both POST and GET variables through the superglobals $_POST and $_GET.
You can either send your paramater in $_GET by including it in the form's action attribute or send it in $_POST by creating an <input type="hidden"> tag within the form

Answer 2

A slash (/) is a reserved character. Encode it with %2F.
http://blooberry.com/indexdot/html/topics/urlencoding.htm#whatwhy

Answer 3

The solution was to do this:
<?php echo $this->Form->create('User',
array('id' => 'loginform', 'type' => 'post',
'url' => array('admin'=>false,'controller'=>'users','action'=>'login','url'=>$this->params['url']['continue']))); ?>
as I have a route already setup to handle the additional URL parameter:
Router::connect('/auth/login', array('controller'=>'users','action'=>'login'));
Router::connect('/auth/login?continue=:url',
array('controller'=>'users','action'=>'login'),
array(
'url' => '[A-Za-z0-9/\._-]+',
'pass' => array('url')
));
If anyone sees any issues with the way I do this though, please feel free to comment.