Horde/Skeleton: Modernized

Over the last months, a lot of new technologies have entered the Horde ecosystem. It was long overdue to modernize the Skeleton example app.

No more un-namespaced code

Skeleton has completely migrated to PSR-4 namespaced code in /src/ rather than traditional, unnamespaced code in /lib/. This includes framework integration classes like Application, Api, Ajax\Application but also the portal blocks.

All application internal classes of skeleton are now served via the Composer Autoloader and follow the PSR-4 standard. This requires the very latest releases of horde/horde (6.0.0alpha6) and horde/core (v3.0.0alpha9) to work correctly. The only exception is the database schema migration which intentionally does not follow regular autoloading conventions.

No more index.php

Client pages that traditionally called into the application’s internal classes have been removed and replaced by routes. This includes the index.php file. A default route handles the skeleton/ and skeleton/index.php cases. The contents of the example UI have not been changed. They are only implemented differently

Using horde/routes and horde/http_server

The new skeleton uses horde/routes to describe available routes in the app and horde/http_server to implement the controller classes behind these routes. The code comes with extensive documentation comments. horde/http_server implements the PSR-15: HTTP Server Request Handlers standard used by most modern PHP Frameworks.

Inter-App API

Skeleton now includes an example of the inter-app API implemented through the registry. The same interface is used as the basis for json-rpc and XMLRPC APIs.

Full Backward Compatibility

The changed libraries still work with unnamespaced or partially converted apps. Implementers can work according to their own schedule. However, there are some rules to keep in mind:

  • The namespaced versions of Application, Api, Test and Ajax\Application take precedence over their unnamespaced counterparts. Implementers can leave the unnamespaced code as-is or turn it into wrappers like
    lib/Application.php
    
    <?php
    /**
     * Backward compatibility wrapper.
     *
     * @deprecated Call into Horde\Skeleton\Application directly instead. 
     */ 
    Skeleton_Application extends Horde\Skeleton\Application {}
    
    
    
  • Portal Blocks should NOT be wrapped or duplicated. They should exist as either namespaced or unnamespaced versions. You can have both types in the same application, but if you have a wrapped or copied block, it will show up twice.
  • Ajax application handler classes only have one integration point, /{lib, src}/Ajax/Application.php. You can upgrade them any time, just change the reference in the Application class. The Ajax Application class itself can be duplicated or wrapped, but the namespaced version will always be chosen. The wrapper would be just a transitional backwards compatibility measure so your application still works with earlier alpha versions of the framework.

Not in this release

The current version of skeleton still leaves room for improvement. Not all external libraries used in the code base are already namespaced or otherwise modernized. The PageOutput helper is still emitting output which needs to be caught and redirected to the output stream as part of the PSR-7 HTTP Response object. Future versions should use a stream-ready implementation to reduce boilerplate. Also, there should be some ready-made controllers for standard cases like UI output or REST.

References

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