no-framework-tutorial/4-http.md

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### HTTP

PHP already has a few things built in to make working with HTTP easier. For example there are the [superglobals](http://php.net/manual/en/language.variables.superglobals.php) that contain the request information.

These are good if you just want to get a small script up and running without much thought on maintenance. However, if you want to write clean, maintainable, [SOLID](http://en.wikipedia.org/wiki/SOLID_%28object-oriented_design%29) code, then you will want a class with a nice object-oriented interface that you can use in your application.

Once again, you don't have to reinvent the wheel and just install a package. I decided to write my own [HTTP component](https://github.com/PatrickLouys/http) because I did not like the existing components, but you don't have to do the same.

Some alternatives: [Symfony HttpFoundation](https://github.com/symfony/HttpFoundation), [Nette HTTP Component](https://github.com/nette/http), [Aura Http](https://github.com/auraphp/Aura.Http), [sabre/http](https://github.com/fruux/sabre-http)

In this tutorial I will use my own HTTP component, but of course you can use whichever package you like most. Just change the code accordingly.

Again, edit the `composer.json` to add the new component and then run `composer update`:

```
"require": {
    "php": ">=5.5.0",
    "filp/whoops": ">=1.1.2",
    "patricklouys/http": ">=1.0.2"
},
```

Now you can add the following below your error handler code in your `Bootstrap.php` (and don't forget to remove the exception):

```
$request = new \Http\HttpRequest($_GET, $_POST, $_COOKIE, $_FILES, $_SERVER);
$response = new \Http\HttpResponse;
```

This sets up the `Request` and `Response` objects that you can use in your other classes to get request data and send a response back to the browser.

To actually send something back, you will also need to add the following snippet at the end of your `Bootstrap.php` file:

```
foreach ($response->getHeaders() as $header) {
    header($header);
}

echo $response->getContent();
```

This will send the response data to the browser. If you don't do this, nothing happens as the `Response` object only stores data. This is handled differently by most other HTTP components where the classes send data back to the browser as a side-effect, so keep that in mind if you use another component.

Right now it is just sending an empty response back to the browser with the status code `200`; to change that, add the following code between the code snippets from above:

```
$content = '<h1>Hello World</h1>';
$response->setContent($content);
```

If you want to try a 404 error, use the following code:

```
$response->setContent('404 - Page not found');
$response->setStatusCode(404);
```

Remember that the object is only storing data, so you if you set multiple status codes before you send the response, only the last one will be applied.

I will show you in later parts how to use the different features of the components. In the meantime, feel free to read the [documentation](https://github.com/PatrickLouys/http) or the source code if you want to find out how something works.

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