phpNS, by Jurrie Overgoor <jurrie@narrowxpres.nl>

phpNS is an implementation of the public API of the NS.
You can find the documentation of that API at http://www.ns.nl/reizigers/blind/_api-nieuw

phpNS is licensed under the GNU General Public License version 3. Please see the COPYING file for more information.

Developer key
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To use phpNS, you must have a developer key. You can request one at https://www.ns.nl/ews-aanvraagformulier/

How to use phpNS
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Step 1: get your developer key at https://www.ns.nl/ews-aanvraagformulier/

Step 2: include the main file
Simply include phpNS.php with the following line:
  require_once('NS.php');

Step 3: decide on the retriever implementation you want to use
A 'retriever' is a class that can request content from ns.nl. At the moment, there's only one retriever:
* cURLRetriever: It uses cURL to request the information.
(Implement your own retriever when you have special needs, like proxy-support or something. To implement your own retriever, extend Retriever and implement the abstract methods.)

Instantiate the cURLRetriever like so:
  $retriever = new cURLRetriever('<YOUR_EMAIL>', '<YOUR_DEVELOPER_KEY>');

Replace <YOUR_EMAIL> with the email you used in step 1, and <YOUR_DEVELOPER_KEY> with the key you got from step 1.

Step 4: decide on the caching implementation
Caching the responses is a good idea, as it lowers the amount of requests you need to do on the NS servers. At the moment, you have the choice between three caching implementations:
* NoCache: does not actually cache
* FileCache: caches responses on disk, in a directory structure
* MySQLCache: caches responses in a MySQL database table

Let's go for the FileCache. We want to cache the responses in a 'tmp' directory below the current directory. We instantiate the FileCache like so:
  require_once('cache/FileCache.php');
  $cache = new FileCache($retriever, "tmp");

Step 5: create an NS object
The NS class is the main class that you'll use for accessing the NS information. Instantiate it like so:
  $ns = new NS($cache);

Step 6: query the NS object for the information you want!
The NS class has several methods. For this example, we want to retrieve a list of all stations:
  $stations = $ns->getStations();

The complete code is like this:
  require_once('NS.php');
  require_once('cache/FileCache.php');
  $retriever = new cURLRetriever('<YOUR_EMAIL>', '<YOUR_DEVELOPER_KEY>');
  $cache = new FileCache($retriever, "tmp");
  $ns = new NS($cache);
  $stations = $ns->getStations();