Templates

Slim does not have a view layer like traditional MVC frameworks. Instead, Slim’s “view” is the HTTP response. Each Slim application route is responsible for preparing and returning an appropriate PSR 7 response object.

Slim’s “view” is the HTTP response.

That being said, the Slim project provides the Twig-View and PHP-View components to help you render templates to a PSR7 Response object.

The slim/twig-view component

The Twig-View PHP component helps you render Twig templates in your application. This component is available on Packagist, and it’s easy to install with Composer like this:

composer require slim/twig-view
Figure 1: Install slim/twig-view component.

Next, you need to register the component as a service on the Slim app’s container like this:

<?php
// Create app
$app = new \Slim\App();

// Get container
$container = $app->getContainer();

// Register component on container
$container['view'] = function ($container) {
    $view = new \Slim\Views\Twig('path/to/templates', [
        'cache' => 'path/to/cache'
    ]);

    // Instantiate and add Slim specific extension
    $basePath = rtrim(str_ireplace('index.php', '', $container['request']->getUri()->getBasePath()), '/');
    $view->addExtension(new Slim\Views\TwigExtension($container['router'], $basePath));

    return $view;
};
Figure 2: Register slim/twig-view component with container.

Note : “cache” could be set to false to disable it, see also ‘auto_reload’ option, useful in development environment. For more information, see Twig environment options

Now you can use the slim/twig-view component service inside an app route to render a template and write it to a PSR 7 Response object like this:

// Render Twig template in route
$app->get('/hello/{name}', function ($request, $response, $args) {
    return $this->view->render($response, 'profile.html', [
        'name' => $args['name']
    ]);
})->setName('profile');

// Run app
$app->run();
Figure 3: Render template with slim/twig-view container service.

In this example, $this->view invoked inside the route callback is a reference to the \Slim\Views\Twig instance returned by the view container service. The \Slim\Views\Twig instance’s render() method accepts a PSR 7 Response object as its first argument, the Twig template path as its second argument, and an array of template variables as its final argument. The render() method returns a new PSR 7 Response object whose body is the rendered Twig template.

The path_for() method

The slim/twig-view component exposes a custom path_for() function to your Twig templates. You can use this function to generate complete URLs to any named route in your Slim application. The path_for() function accepts two arguments:

  1. A route name
  2. A hash of route placeholder names and replacement values

The second argument’s keys should correspond to the selected route’s pattern placeholders. This is an example Twig template that draws a link URL for the “profile” named route shown in the example Slim application above.


{% extends "layout.html" %}

{% block body %}
<h1>User List</h1>
<ul>
    <li><a href="{{ path_for('profile', { 'name': 'josh' }) }}">Josh</a></li>
</ul>
{% endblock %}

Extending twig

Twig can be extended with additional filters, functions, global variables, tags and more.

To register a filter, add the following after registering the view component with the container:

$filter = new Twig_SimpleFilter('rot13', function ($string) {
  return str_rot13($string);
});

$container->get('view')->getEnvironment()->addFilter($filter);
Figure 4: Registering a filter with Twig

This adds a “rot13” filter to twig:


{# outputs "Slim Framework" #}
{{ 'Fyvz Senzrjbex'|rot13}}

To register a function, add the following after registering the view component with the container:

$function = new Twig_SimpleFunction('shortest', function ($a, $b) {
  return strlen($a) <= strlen($b) ? $a : $b;
});

$container->get('view')->getEnvironment()->addFunction($function);
Figure 5: Registering a function with Twig

This adds a “shortest” function to twig:


{# outputs "Slim" #}
{{ shortest('Slim', 'Framework') }}

The twig documentation contains more details on Twig extensions.

The slim/php-view component

The PHP-View PHP component helps you render PHP templates. This component is available on Packagist and can be installed using Composer like this:

composer require slim/php-view
Figure 6: Install slim/php-view component.

To register this component as a service on Slim App’s container, do this:

<?php
// Create app
$app = new \Slim\App();

// Get container
$container = $app->getContainer();

// Register component on container
$container['view'] = function ($container) {
    return new \Slim\Views\PhpRenderer('path/to/templates/with/trailing/slash/');
};
Figure 7: Register slim/php-view component with container.

Use the view component to render a PHP view like this:


// Render PHP template in route
$app->get('/hello/{name}', function ($request, $response, $args) {
    return $this->view->render($response, 'profile.html', [
        'name' => $args['name']
    ]);
})->setName('profile');

// Run app
$app->run();
Figure 8: Render template with slim/php-view container service.

Other template systems

You are not limited to the Twig-View and PHP-View components. You can use any PHP template system provided that you ultimately write the rendered template output to the PSR 7 Response object’s body.