# Execution Pipeline
## Introduction
This page documents all the steps from an URL request to the delivered page.
## .htaccess and RewriteRule
Silverstripe uses **[mod_rewrite](http://httpd.apache.org/docs/2.0/mod/mod_rewrite.html)** to deal with page requests.
So instead of having your normal everyday `index.php` file which tells all, you need to look elsewhere.
The basic .htaccess file after installing SilverStripe look like this:
### SILVERSTRIPE START ###
Order deny,allow
Deny from all
Allow from 127.0.0.1
RewriteEngine On
RewriteCond %{REQUEST_URI} !(\.gif$)|(\.jpg$)|(\.png$)|(\.css$)|(\.js$)
RewriteCond %{REQUEST_URI} ^(.*)$
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule .* framework/main.php?url=%1&%{QUERY_STRING} [L]
### SILVERSTRIPE END ###
The `` section denies direct access to the template files from anywhere but the server itself.
The next section enables the rewriting engine and rewrites requests to `framework/main.php` if they meet the following
criteria:
* URI doesn't end in .gif, .jpg, .png, .css, or .js
* The requested file doesn't exist on the filesystem `framework/main.php` is called with the REQUEST_FILENAME (%1) as the `url` parameter and also appends the original
QUERY_STRING.
See the [mod_rewrite documentation](http://httpd.apache.org/docs/2.0/mod/mod_rewrite.html) for more information on how
mod_rewrite works.
## main.php
All requests go through `main.php`, which sets up the environment and then hands control over to `Director`.
## Director and URL patterns
main.php relies on `[api:Director]` to work out which controller should handle this request. `[api:Director]` will instantiate that
controller object and then call `[api:Controller::run()]`.
In general, the URL is build up as follows: `page/action/ID/otherID` - e.g. http://www.mysite.com/mypage/addToCart/12.
This will add an object with ID 12 to the cart.
When you create a function, you can access the ID like this:
:::php
public function addToCart ($request) {
$param = $request->allParams();
echo "my ID = " . $param["ID"];
$obj = MyProduct::get()->byID($param["ID"]);
$obj->addNow();
}
## Controllers and actions
`[api:Controller]`s are the building blocks of your application.
**See:** The API documentation for `[api:Controller]`
You can access the following controller-method with /team/signup
:::php
class Team extends DataObject {}
class Team_Controller extends Controller {
private static $allowed_actions = array('signup');
public function signup($id, $otherId) {
return $this->renderWith('MyTemplate');
}
}
## SSViewer template rendering
See [templates](/topics/templates) for information on the SSViewer template system.