wiki.techinc.nl/includes/api/ApiModuleManager.php
daniel baa11f7430 Allow factory functions for creating API modules.
This enables factory functions to be registered for API modules,
in addition to the module class itself. This allows modules to
use proper dependency injection via the modules constructor.

Example:

  $wgAPIModules['foo'] = array(
    'class' => 'ApiFoo',
    'factory' => function( $main, $action ) { ... }
  )

Change-Id: Ieb85493a7765f466317f5fa74b0b0e262220deab
2014-08-06 22:58:14 +02:00

278 lines
8 KiB
PHP

<?php
/**
*
*
* Created on Dec 27, 2012
*
* Copyright © 2012 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
* @since 1.21
*/
/**
* This class holds a list of modules and handles instantiation
*
* @since 1.21
* @ingroup API
*/
class ApiModuleManager extends ContextSource {
/**
* @var ApiBase
*/
private $mParent;
/**
* @var ApiBase[]
*/
private $mInstances = array();
/**
* @var null[]
*/
private $mGroups = array();
/**
* @var array[]
*/
private $mModules = array();
/**
* Construct new module manager
* @param ApiBase $parentModule Parent module instance will be used during instantiation
*/
public function __construct( ApiBase $parentModule ) {
$this->mParent = $parentModule;
}
/**
* Add a list of modules to the manager. Each module is described
* by a module spec.
*
* Each module spec is an associative array containing at least
* the 'class' key for the module's class, and optionally a
* 'factory' key for the factory function to use for the module.
*
* That factory function will be called with two parameters,
* the parent module (an instance of ApiBase, usually ApiMain)
* and the name the module was registered under. The return
* value must be an instance of the class given in the 'class'
* field.
*
* For backward compatibility, the module spec may also be a
* simple string containing the module's class name. In that
* case, the class' constructor will be called with the parent
* module and module name as parameters, as described above.
*
* Examples for defining module specs:
*
* @code
* $modules['foo'] = 'ApiFoo';
* $modules['bar'] = array(
* 'class' => 'ApiBar',
* 'factory' => function( $main, $name ) { ... }
* );
* $modules['xyzzy'] = array(
* 'class' => 'ApiXyzzy',
* 'factory' => array( 'XyzzyFactory', 'newApiModule' )
* );
* @endcode
*
* @param array $modules A map of ModuleName => ModuleSpec; The ModuleSpec
* is either a string containing the module's class name, or an associative
* array (see above for details).
* @param string $group Which group modules belong to (action,format,...)
*/
public function addModules( array $modules, $group ) {
foreach ( $modules as $name => $moduleSpec ) {
if ( is_array( $moduleSpec ) ) {
$class = $moduleSpec['class'];
$factory = ( isset( $moduleSpec['factory'] ) ? $moduleSpec['factory'] : null );
} else {
$class = $moduleSpec;
$factory = null;
}
$this->addModule( $name, $group, $class, $factory );
}
}
/**
* Add or overwrite a module in this ApiMain instance. Intended for use by extending
* classes who wish to add their own modules to their lexicon or override the
* behavior of inherent ones.
*
* @param string $name The identifier for this module.
* @param string $group Name of the module group
* @param string $class The class where this module is implemented.
* @param callable|null $factory Callback for instantiating the module.
*
* @throws InvalidArgumentException
*/
public function addModule( $name, $group, $class, $factory = null ) {
if ( !is_string( $name ) ) {
throw new InvalidArgumentException( '$name must be a string' );
}
if ( !is_string( $group ) ) {
throw new InvalidArgumentException( '$group must be a string' );
}
if ( !is_string( $class ) ) {
throw new InvalidArgumentException( '$class must be a string' );
}
if ( $factory !== null && !is_callable( $factory ) ) {
throw new InvalidArgumentException( '$factory must be a callable (or null)' );
}
$this->mGroups[$group] = null;
$this->mModules[$name] = array( $group, $class, $factory );
}
/**
* Get module instance by name, or instantiate it if it does not exist
*
* @param string $moduleName Module name
* @param string $group Optionally validate that the module is in a specific group
* @param bool $ignoreCache If true, force-creates a new instance and does not cache it
*
* @return ApiBase|null The new module instance, or null if failed
*/
public function getModule( $moduleName, $group = null, $ignoreCache = false ) {
if ( !isset( $this->mModules[$moduleName] ) ) {
return null;
}
list( $moduleGroup, $moduleClass, $moduleFactory ) = $this->mModules[$moduleName];
if ( $group !== null && $moduleGroup !== $group ) {
return null;
}
if ( !$ignoreCache && isset( $this->mInstances[$moduleName] ) ) {
// already exists
return $this->mInstances[$moduleName];
} else {
// new instance
$instance = $this->instantiateModule( $moduleName, $moduleClass, $moduleFactory );
if ( !$ignoreCache ) {
// cache this instance in case it is needed later
$this->mInstances[$moduleName] = $instance;
}
return $instance;
}
}
/**
* Instantiate the module using the given class or factory function.
*
* @param string $name The identifier for this module.
* @param string $class The class where this module is implemented.
* @param callable|null $factory Callback for instantiating the module.
*
* @throws MWException
* @return ApiBase
*/
private function instantiateModule( $name, $class, $factory = null ) {
if ( $factory !== null ) {
// create instance from factory
$instance = call_user_func( $factory, $this->mParent, $name );
if ( ! $instance instanceof $class ) {
throw new MWException( "The factory function for module $name did not return an instance of $class!" );
}
} else {
// create instance from class name
$instance = new $class( $this->mParent, $name );
}
return $instance;
}
/**
* Get an array of modules in a specific group or all if no group is set.
* @param string $group Optional group filter
* @return array List of module names
*/
public function getNames( $group = null ) {
if ( $group === null ) {
return array_keys( $this->mModules );
}
$result = array();
foreach ( $this->mModules as $name => $grpCls ) {
if ( $grpCls[0] === $group ) {
$result[] = $name;
}
}
return $result;
}
/**
* Create an array of (moduleName => moduleClass) for a specific group or for all.
* @param string $group Name of the group to get or null for all
* @return array Name=>class map
*/
public function getNamesWithClasses( $group = null ) {
$result = array();
foreach ( $this->mModules as $name => $grpCls ) {
if ( $group === null || $grpCls[0] === $group ) {
$result[$name] = $grpCls[1];
}
}
return $result;
}
/**
* Returns true if the specific module is defined at all or in a specific group.
* @param string $moduleName Module name
* @param string $group Group name to check against, or null to check all groups,
* @return bool True if defined
*/
public function isDefined( $moduleName, $group = null ) {
if ( isset( $this->mModules[$moduleName] ) ) {
return $group === null || $this->mModules[$moduleName][0] === $group;
}
return false;
}
/**
* Returns the group name for the given module
* @param string $moduleName
* @return string Group name or null if missing
*/
public function getModuleGroup( $moduleName ) {
if ( isset( $this->mModules[$moduleName] ) ) {
return $this->mModules[$moduleName][0];
}
return null;
}
/**
* Get a list of groups this manager contains.
* @return array
*/
public function getGroups() {
return array_keys( $this->mGroups );
}
}