deefour/presenter

Presenters/Decorators for PHP Objects

3.0.0 2017-07-21 18:04 UTC

README

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Object-oriented presentation logic.

Getting Started

Run the following to add Presenter to your project's composer.json. See Packagist for specific versions.

composer require deefour/presenter

>=PHP5.5.0 is required.

The Resolver

The Deefour\Presenter\Resolver determines the FQN of a presenter class associated with an object. The default behavior of the resolver is to append 'Presenter' to the Article FQN.

use Deefour\Presenter\Resolver;

(new Resolver)->presenter(new Article); //=> 'ArticlePresenter'

This behavior can be customized by passing a callable to the resolver.

use Deefour\Presenter\Resolver;

$resolver = new Resolver;

$resolver->resolveWith(function ($instance) {
  return "App\Presenters\" . get_class($instance) . 'Presenter';
});

$resolver->presenter(new Article); //=> 'App\Presenters\ArticlePresenter'

The resolver will look for a modelClass() method on an object. If found, the returned FQN will be used instead of the object itself.

class BlogPost
{
  static public function modelClass()
  {
      return Article::class;
  }
}

(new Resolver)->presenter(new BlogPost); //=> 'ArticlePresenter'

Instantiation

Instantiating an instance of a presenter is your responsibility.

use Deefour\Presenter\Resolver;

$article       = new Article;
$presenterName = (new Resolver)->presenter($article);
$presenter     = new $presenterName($article);
use Deefour\Presenter\Resolver;

(new Resolver)->presenter(new Article); //=> 'BlogPresenter'

If the resulting FQN from the resolver does not match an existing, valid class name, null will be returned or a NotDefinedException will be thrown.

use Deefour\Presenter\Resolver;

(new Resolver)->presenter(new ObjectWithoutPresenter); //=> null
(new Resolver)->presenterOrFail(new ObjectWithoutPresenter); //=> throws NotDefinedException

Presenters

The presenters themselves extend Deefour\Presenter\Presenter.

use Deefour\Presenter\Presenter;

class ArticlePresenter extends Presenter
{
    public function isDraft()
    {
        return $this->_model->isDraft() ? 'Yes' : 'No';
    }
}

The API

A quick overview of the API available.

use Deefour\Producer\Factory;

$presenter = (new Factory)->make(new Article, 'presenter'); //=> ArticlePolicy

$presenter->_model; //=> Article

$presenter->_model->isDraft(); //=> false
$presenter->isDraft(); //=> 'No'
$presenter->is_draft; //=> 'No'

$presenter->_model()->published; //=> true
$presenter->published; //=> true

A few things to notice:

  • The underlying object decorated by the presenter can be accessed via the $_model property or model() method.
  • Any property or method publicly accessible on the underlying object can also be accessed directly through the presenter.
  • Any publicly accessible, camel-cased method on the presenter or underlying model can be accessed via snake-cased property access.

Automatic Presenter Resolution

When a property or method is resolved through the __get() or __call() methods on the presenter, an attempt will be made to resolve and wrap the return value in a presenter too.

namespace App;

use Illuminate\Support\Collection;

class Article
{
    public function category()
    {
        return new Category;
    }

    public function tags()
    {
        $collection = new Collection;

        $collection->push(new Tag);
        $collection->push(new Tag);
        $collection->push(new Tag);

        return $collection;
    }
}

Given the existence of ArticlePresenter, CategoryPresenter, and TagPresenter, the following will be returned

use Deefour\Presenter\Resolver;

$presenter = (new Resolver)->presenter(new Article); //=> ArticlePresenter

(new $presenter)->category;      //=> CategoryPresenter
(new $presenter)->tags->first(); //=> TagPresenter

Note: The collection resolution works by looking for an instance of IteratorAggregate. The iterator is used to loop through the collection and generate presenters for each item. An attempt is then made to instantiate a new instance of the original object implementing IteratorAggregate. That is the return value.

If you want access to the raw association, simply request it from the underlying object.

$presenter->_model->tags()->first(); //=> Tag

Contribute

Changelog

3.0.0 - July 20, 2017

  • The resolver no longer accepts an object during instantiation. Instead, objects are passed directly to the presenter() and presenterOrFail() methods.
  • A new resolveWith() method on the resolver accepts a callable to customize resolution.
  • Support for the presenterClass() has been removed from the resolver in favor of the new resolveWith() method on the resolver. You can pass a callable with your existing presenterClass() logic to the resolver instead.
  • Model access should only be done through the new model() method. Access to _model has been disabled.

2.0.0 - February 12, 2017

  • Replaced Factory with new Resolver class.
  • Removed dependency on deefour\producer
  • Removed Presentable contract
  • Simplified README.md

1.0.0 - October 7, 2015

  • Release 1.0.0.

0.8.0 - August 8, 2015

  • Compat changes for updates to deefour/producer.
  • New Factory class is available to prevent the need to interact directly with the factory in deefour/producer.
  • Abstracted presenter resolution out to new deefour/producer.
  • Removed the Laravel service provider and facade. The 'producer' service in deefour/producer should be used instead.

0.6.2 - June 5, 2015

  • Now following PSR-2.

0.6.0 - May 24, 2015

  • Removed model() method on base presenter.
  • Renamed $model property to $_model to avoid conflicts with an actual model attribute with the name 'model'.
  • Presenters now only provide property access to public properties on the presenter.
  • Prefixed API methods/properties with _ on the base presenter to further avoid conflicts with attribute overrides.
  • Made $_model property public.
  • Updates to code formatting.

0.5.0 - April 27, 2015

  • Snake-case to camel-case method conversions are now cached for performance
  • Exceptions are no longer thrown for missing properties/methods. See 6f33dda for an explanation.

0.4.0 - March 19, 2015

  • Rename presenter() helper to present()
  • Remove helpers.php from Composer autoload. Developers should be able to choose whether these functions are included.
  • Cleaning docblocks.
  • Type-hinting the presenter factory.
  • Renaming Presentable trait to ResolvesPresenters to avoid naming conflict with \Deefour\Presenter\Contracts\Presentable.

0.3.0 - March 16, 2015

  • Allow presenters to be explicitly requested, bypassing the model default. For example
      $article = new Article;
      echo get_class($article->presenter()); //=> 'ArticlePresenter'
      echo get_class($article->presenter(FeaturedArticlePresenter::class)); //=> 'FeaturedArticlePresenter'

0.2.3 - February 27, 2015

  • Illuminate\Support\Collection instances and native PHP arrays can now be passed directly into the presenter() helper.

0.2.2 - February 20, 2015

  • Updated support for Laravel's Eloquent relations. Relations are now fetched and converted to presenter-wrapped objects or collections when requested.

0.2.0 - February 5, 2015

  • Fix service provider.
  • Make global presenter() work with Laravel IoC container if it's available.
  • Move trait.

0.1.0 - November 21, 2014

  • Initial release.

License

Copyright (c) 2014 Jason Daly (deefour). Released under the MIT License.