Although still in beta lots of plugins out there are following suit. Plus in CraftCMS 3 will be very different and basically a complete rework but 95% of the functionality still exist.

Plus offers a way to attach behaviors to your elements using Craft's own $element->attachBehavior() method. Supplies a global variable that can access your services directly from your templates as well as a few built in behaviors and twig filters for fun.

With CraftCMS 3 and the new way to install plugins we had to come up with way to easily allow you the developer to extend our plugin as before but without needing to dig into the vendor directory. Although possible, we would hate for you to have to do that. Instead, a plus.php config file will communicate to the plus core code how it will be "extended" on init. More information on this below.

This plugin is maintained by Franco Valdes.

• cd into your project's direction
• run composer require fvaldes/plus
• Go to Settings > Plugins from your Craft control panel and enable the plugin

Now that the core Plus plugin is installed and enabled you can start to extend the plugin from your project's root directory without having to dig into the vendor files.

• First create a folder for your extender files. In my particular use case I have named it the site name "union".
• In that folder you can create sub directories for your behaviors, services, controllers, twigextensions, variables and more.
• Namespace your files properly as we will need to use this in the config file.
  • Example: namespace union/behaviors/entries
  • Example: namespace union/services
  • Example: namespace union/twigextensions
  • You get the point...
• Lastly, lets connect it all by creating a plus.php file in main craft config directory and it should look something like this...

  <?php
  return [
      "namespace" => "union\\",
      "folderPath" => CRAFT_BASE_PATH . '/union',
      "controllerNamespace" => "union\\controllers",
      "twigextension" => "union\\twigextensions\\UnionTwigExtension",
      "services" => [
          "meta" => "union\\services\\MetaService"
      ],
      "variables" => [
          "name" => "union\\twigextensions\\UnionVariable"
      ]
  ];
  

• Namespace: Namespace of your extender
• Folder Path: Path to your extenders
• Controller Namespace: Namespace root of your controllers
• Twig Extension: Twig extension class with full namespace
• Services: Array map of services
• Variables: Array map of variables

• Out of the box

  • AssetBehavior
    • Craft Twig Standard Way {{ entry.assetHandle.one.getUrl() }}
    • New Way {{ entry._assetUrl('assetHandle') }}
    • Optional {{ entry._assetUrl('assetHandle', 'squareTransformHandle') }}
    • Eager loaded resources would use {{ entry._eAssetUrl('assetHandle') }}
  • Video Url Filter
    • Currently supports vimeo and youtube urls
    • Usage:: {{ entry.videoUrl | videoEmbedUrl }}

• Behaviors

  Behaviors are all bound to the handle of the element.

  • Entries: Entry -> Section -> Handle
  • Categories: Category -> Group -> Handle
  • GlobalSet: Global -> Handle
  • Matrixblock: MatrixBlock -> Field -> Handle

  Create a file for the element in question (plus the word behavior). Example for the Home (single).

  <?php 
  namespace union/behaviors/entries
  use fvaldes33\plus\Plugin; //if you need to access the core plugin
  use fvaldes33\plus\behaviors\entries\BaseEntryBehavior;
  
  class HomeBehavior extends BaseEntryBehavior
  {
      public function _somethingInteresting()
      {
          return 'something interesting';
      }
  }
  

  I wont go into tons of detail on how to add behaviors or why we do so, Plus is just the facilitator. Reference the CraftCMS docs or Yii2 docs to get more details about behaviors.

• Services

  Services will map 1/1 to how services work inside the core plugin and docs for that are already available in the CraftCMS docs github page Docs. The one added benefit of Plus here is the plus variable and its ability to access any of your services from within your templates without needing to create new variables and/or twig extensions. I will give two examples here...

  Service will look like this

  <?php
  namespace union\services;
  
  use Craft;
  use craft\base\Component;
  use fvaldes33\plus\Plugin;
  
  class QuoteService extends Component
  {
      public function getRandomQuote()
      {
          // code here
      }
  }
  

  Here you have the normal php way of accessing your service:

  <?php 
  namespace union/behaviors/entries
  use fvaldes33\plus\Plugin; //if you need to access the core plugin
  use fvaldes33\plus\behaviors\entries\BaseEntryBehavior;
  
  class HomeBehavior extends BaseEntryBehavior
  {
      public function _somethingInteresting()
      {
          $quote = Plugin::$plugin->quote->getRandomQuote();
          return $quote;
      }
  }
  

  In twig w/Plus

  {{ plus('quote').getRandomQuote() }}
  

If you need a feature, let me know and I'll add it as soon as reasonably possible. Plus is actively maintained, and I accept relevant, feature-adding pull requests. If you encounter any issues, please open an issue and I'll work with you and patch the problem. Thanks!