README

This package is deprecated. View Models are now baked into the Lumberjack core.

View Models

Here, a ViewModel refers to something that takes data and transforms it into the correct format for a specific view. They are input-output machines.

For example, for this twig view:

{% for link in links %}
    <a href="{{ link.url }}">{{ link.title }}</a>
{% endfor %}

You will need to construct an array that looks like this (e.g. in your controller):

// Get pages from the database somehow
$pages = Page::all();

$data = ['links' => []];

foreach ($pages as $page) {
    // Map the page to the correct structure for the view
    $data['links'][] = [
        'url' => $page->permalink,
        'title' => $page->post_title,
    ];
}

** ViewModels abstract away that transformation. This means you don't have to duplicate that transformation logic across multiple controllers, making your code eaiser to change.**

Postcardware

You're free to use this package (it's MIT-licensed), but if it makes it to your production environment we highly appreciate you sending us a postcard from your hometown, mentioning which of our package(s) you are using.

Our address is: 12 Basepoint, Andersons Road, Southampton, Hampshire, SO14 5FE.

Installation

You can install the package via composer:

composer require rareloop/view-models

View Model Usage

They should always return an array. The easiest way to achieve this is to run your data through the compose method on the View Model.

They should not fetch data from anywhere (e.g. database). This is the job of a ViewModelComposer.

Using an example ViewModel (e.g. in a controller):

$params = new ParameterBag([
    'links' => [
        'https://google.com',
        'https://rareloop.com',
    ],
]);

$context['links'] = \App\ViewModels\Links::make($params);

Here is an example ViewModel implementation:

namespace App\ViewModels\Links;

use Rareloop\ViewModels\ParameterBag;
use Rareloop\ViewModels\ViewModel;

class Links extends ViewModel
{
    public static function make(ParameterBag $params): array
    {
        // Transform the data into the correct structure
        $data = array_map(function ($item) {
            return [
                'url' => $item['ID'],
            ];
        }, $params->links);

        // Make sure the data is an array
        return static::compose($data);
    }
}

Introducing View Model Composers

A ViewModelComposer is simply a wrapper around a ViewModel, but is only concerned how to get data ready for a ViewModel.

These should be used instead of duplicating logic when creating ViewModels (e.g. in controllers).

Example ViewModelComposer implementation:

class RelatedLinks
{
    public static function make(): array
    {
        // e.g. you could get the data out of the database for the related links for this page
        $args = new ParameterBag([
            'links' => [
                'http://google.com',
                'https://rareloop.com',
            ],
        ]);

        return Links::make($args);
    }
}

Changelog

Please see CHANGELOG for more information what has changed recently.

Testing

composer test

Contributing

Please see CONTRIBUTING for details.

Security

If you discover any security related issues, please email info@rareloop.com instead of using the issue tracker.

License

The MIT License (MIT). Please see License File for more information.