laika-framework

Filters

A filter is middleware that runs after the controller. It receives the response string and can log it, change it, or replace it.

Create via CLI

php laika filter:make LogAccess

Filters live in lf-app/Filter/, namespace App\Filter.

Anatomy

namespace App\Filter;

use Laika\Engine\Route\Contracts\FilterInterface;

class LogAccess implements FilterInterface
{
    public function terminate(callable $next, ?string $response, array &$params): ?string
    {
        // ... your code ...

        return $next($response);   // pass the (possibly changed) response on
    }
}

$response — the controller’s return value (or a pipeline’s short-circuit string). null when nothing was returned.
$params — the same array the pipelines and controller received, by reference.
Whatever the last filter returns is sent.

Attaching Filters

use Laika\Engine\Route\Url;

Url::get('/', 'HomeController@index')->filter(LogAccess::class);
Url::get('/dashboard', 'DashboardController@index')->filter(['LogAccess', 'Minify']);

// Every route in the application
Url::globalFilter(['LogAccess']);

Short names resolve to App\Filter\...; a fully qualified class name is used as-is.

Return Behavior

In `terminate()` you…	Remaining filters	Response sent
`return $next($response);`	run	the response, as passed along
`return $next($response, false);`	skipped	`$response`
`return $next('other');`	run	`'other'` replaces the response
`return $next('other', false);`	skipped	`'other'`
`return 'other';` (no `$next`)	skipped	`'other'`

Examples

Log every response:

public function terminate(callable $next, ?string $response, array &$params): ?string
{
    error_log(sprintf('%s %s -> %d bytes',
        $_SERVER['REQUEST_METHOD'] ?? '-', $_SERVER['REQUEST_URI'] ?? '-', strlen((string) $response)));

    return $next($response);
}

Add a header:

use Laika\Engine\Services\Response;

public function terminate(callable $next, ?string $response, array &$params): ?string
{
    Response::setHeader('X-Robots-Tag', 'noindex');
    return $next($response);
}

Maintenance mode:

public function terminate(callable $next, ?string $response, array &$params): ?string
{
    if (option_bool('maintenance')) {
        \Laika\Engine\Services\Response::setStatus(503);
        return '<h1>Down for maintenance</h1>';
    }

    return $next($response);
}

Passing Config Args

Same syntax as pipelines. The values arrive in $params, and are strings:

Url::get('/reports', 'ReportController@index')->filter(['LogAccess|level=info']);

public function terminate(callable $next, ?string $response, array &$params): ?string
{
    error_log('level=' . ($params['level'] ?? 'default'));
    return $next($response);
}

Filter args are merged when that filter runs, so only later filters see them — never the controller.

Dependencies

Filters are built through the container, so type-hint dependencies in the constructor:

use App\Support\AuditLog;

class LogAccess implements FilterInterface
{
    public function __construct(private AuditLog $log) {}

    public function terminate(callable $next, ?string $response, array &$params): ?string
    {
        $this->log->write($params);
        return $next($response);
    }
}

The rules are the same as for pipelines: concrete classes auto-wire, interfaces must be bound in a relay provider, and relays should be called statically rather than injected.

Order and Scope

Order: global filters → group filters (Handler::registerGroup()) → route ->filter() → group-chained ->filter().
Filters form an onion: code after $next($response) runs in reverse order.
Filters run on a controller’s response and on a pipeline’s short-circuit string. They do not run on 404 pages, fallbacks, or static files.

Rules

Implement Laika\Engine\Route\Contracts\FilterInterface (any class with a matching terminate() method is accepted).
Signature: terminate(callable $next, ?string $response, array &$params): ?string
An unknown filter name throws FilterException (status 500).

CLI Reference

Command	Description
`php laika filter:make <name>`	Create a filter class
`php laika filter:list`	List filter classes
`php laika filter:remove <name>`	Delete a filter class
`php laika filter:rename --old=<name> --new=<name>`	Rename a filter class