mediawiki-skins-Vector/includes/Constants.php
Sam Smith 84226b41b6 featureManager: Add DynamicConfigRequirement requirement
We expect the vast majority of requirements and features to be defined
in services as possible. However, there are some "complex" requirements
that require additional application/HTTP request state. Unfortunately,
service wiring is done before some of that state is available.

I65702426 attempted to work around this by requiring clients of the
Feature Manager to pass that additional state on every interaction with
the system. Those complex requirements would then select the parts of
the state that they required when it was required. However
implementations of \IContextSource are God objects and their use should
be limited.

Whilst reviewing I65702426, Stephen Niedzielski mentioned that the
application state being available is a requirement. This remarkably
simple solution:

- Keeps the Requirement interface and FeatureManager API free of God
  objects;

- Is true to the nature of the Feature Manager - it makes clear and
  centralizes the various checks for application state being available
  across the codebase; and

- Inject a Requirement implementations' dependencies at construction
  time

It just so happens that the $wgFullyInitialised variable flags whether
the application state is available...

Changes:

- Add the the FeatureManager\Requirements\DynamicConfigRequirement class
  and tests. The DynamicConfigRequirement lazily evaluates a single
  configuration value whenever ::isMet is invoked

- Register an DynamicConfigRequirement instance, configured to evaluate
  $wgFullyInitialised while constructing the Vector.FeatureManager
  service

Bug: T244481
Change-Id: I7a2cdc2dfdf20d78e4548f07cf53994563b234b3
2020-03-18 10:10:42 +00:00

82 lines
1.8 KiB
PHP

<?php
namespace Vector;
use FatalError;
/**
* A namespace for Vector constants for internal Vector usage only. **Do not rely on this file as an
* API as it may change without warning at any time.**
*/
final class Constants {
/**
* This is tightly coupled to the ConfigRegistry field in skin.json.
* @var string
*/
public const SKIN_NAME = 'vector';
// These are tightly coupled to PREF_KEY_SKIN_VERSION and skin.json's configs. See skin.json for
// documentation.
/**
* @var string
*/
public const SKIN_VERSION_LEGACY = '1';
/**
* @var string
*/
public const SKIN_VERSION_LATEST = '2';
/**
* @var string
*/
public const SERVICE_CONFIG = 'Vector.Config';
/**
* @var string
*/
public const SERVICE_FEATURE_MANAGER = 'Vector.FeatureManager';
// These are tightly coupled to skin.json's config.
/**
* @var string
*/
public const CONFIG_KEY_SHOW_SKIN_PREFERENCES = 'VectorShowSkinPreferences';
/**
* @var string
*/
public const CONFIG_KEY_DEFAULT_SKIN_VERSION = 'VectorDefaultSkinVersion';
/**
* @var string
*/
public const CONFIG_KEY_DEFAULT_SKIN_VERSION_FOR_EXISTING_ACCOUNTS =
'VectorDefaultSkinVersionForExistingAccounts';
/**
* @var string
*/
public const CONFIG_KEY_DEFAULT_SKIN_VERSION_FOR_NEW_ACCOUNTS =
'VectorDefaultSkinVersionForNewAccounts';
/**
* @var string
*/
public const PREF_KEY_SKIN_VERSION = 'VectorSkinVersion';
// These are used in the Feature Management System.
/**
* @var string
*/
public const CONFIG_KEY_FULLY_INITIALISED = 'FullyInitialised';
/**
* @var string
*/
public const REQUIREMENT_FULLY_INITIALISED = 'FullyInitialised';
/**
* This class is for namespacing constants only. Forbid construction.
* @throws FatalError
*/
private function __construct() {
throw new FatalError( "Cannot construct a utility class." );
}
}