Controllers

TL;DR

• Use a controller for the logic of your templates.
• Any data returned by a controller’s function is available everywhere in the corresponding template.
• A controller must have the same file name as the corresponding template file.
• Save controllers in /site/controllers.

The controllers directory

Controllers go into /site/controllers. Create the directory if it's not there yet. Controllers are named exactly like the templates they belong to:

Kirby will automatically load the controller for your template if it can find one.

General site controller

You can also use a general site controller called site.php which you put into your /site/controllers folder like any other page controller. Such a general site controller is useful if multiple templates share the same logic, while they don't need any template specific logic. It works like a normal page controller but will only be applied to templates that do not have a specific page controller. It will not be loaded in addition to a template-specific controller.

If you want to share logic between multiple templates and still add template specific logic in a dedicated page controller, check out the Shared controllers recipe.

Creating a controller

The basic code for a controller is very simple. It's an anonymous function that should return the variables that you want to pass to the template as an associative array.

<?php

return function () {
  return [
    'foo' => 'my first template variable',
    'bar' => 'my second template variable'
  ];
};

In this case the $foo and $bar variables will be available in the corresponding template.

Accessing Kirby objects in your controller

Like in templates, you can access the $site, $page, $pages and $kirby objects by loading them as arguments to the anonymous function. Kirby will magically inject the right objects for you:

A single object

return function ($page) {
    // do something with the page
};

Multiple objects

return function ($page, $site, $kirby) {
    // do something with the page, site and kirby
};

Order doesn't matter

return function ($site, $page, $kirby) {
    // do something with the page, site and kirby
};

A real world example

A typical example where a controller can come in handy is a blog template. Fetching the right articles can take a couple lines of code and it's much nicer to wrap these in a controller. So let's create /site/templates/blog.php and /site/controllers/blog.php

The controller

The controller will take care of fetching the right articles and add pagination to them. It will then pass the $articles and $pagination variables to the template to keep it clean.

<?php

return function ($page) {

  // get all articles
  $articles = $page->children()->listed()->flip();

  // add a tag filter
  if ($tag = get('tag')) {
    $articles = $articles->filterBy('tags', '=', $tag, ',');
  }

  // add pagination
  $articles = $articles->paginate(20);

  // create a shortcut for pagination
  $pagination = $articles->pagination();

  // pass $articles and $pagination to the template
  return [
    'articles' => $articles,
    'pagination' => $pagination
  ];

};

The template

With such a controller, the template can be super clean. A foreach loop for the articles and the prev/next pagination and you're done.

<?php snippet('header') ?>

<?php foreach ($articles as $article): ?>
<?php snippet('article', ['article' => $article]) ?>
<?php endforeach ?>

<nav class="pagination">

  <?php if ($pagination->hasPrevPage()): ?>
  <a href="<?= $pagination->prevPageUrl() ?>">previous articles</a>
  <?php endif ?>

  <?php if ($pagination->hasNextPage()): ?>
  <a href="<?= $pagination->nextPageUrl() ?>">next articles</a>
  <?php endif ?>

</nav>

<?php snippet('footer') ?>

Arguments from the router

If you work with additional routes and you want to access the arguments from the router in your controller, you can use Kirby's route() method to access an array of router arguments.

<?php

return function ($kirby) {

  $args = $kirby->route()->arguments();
    // contains all arguments from the current route

};

Arguments from $page->render() in route

When using the $page->render() method to return a page in a route, you can send an array of additional data with it:

return [
    'routes' => [
        [
            'pattern' => 'blog/tag/(:any)',
            'action' => function ($value) {
                $data = [
                  'tag' => $value,
                ];
                return page('blog')->render($data);
            }
        ]
    ]
];

In the controller, you can load each variable that you passed to the render() method in the route into the controller's anonymous function and then work with it.

<?php

return function ($page, $tag) {

  $articles = $page->children()->listed();

    if ($tag) {
        $articles = $articles->filterBy('tags', $tag, ',');
    }

    return [
        'articles' => $articles
    ];

};

More information

Shared controllers