Add a way for packagers to override some installation details

[mediawiki.git] / includes / context / DerivativeContext.php

<?php
/**
 * Request-dependant objects containers.
 *
 * 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
 *
 * @since 1.19
 *
 * @author Daniel Friesen
 * @file
 */

/**
 * An IContextSource implementation which will inherit context from another source
 * but allow individual pieces of context to be changed locally
 * eg: A ContextSource that can inherit from the main RequestContext but have
 *     a different Title instance set on it.
 */
class DerivativeContext extends ContextSource {

        /**
         * @var WebRequest
         */
        private $request;

        /**
         * @var Title
         */
        private $title;

        /**
         * @var WikiPage
         */
        private $wikipage;

        /**
         * @var OutputPage
         */
        private $output;

        /**
         * @var User
         */
        private $user;

        /**
         * @var Language
         */
        private $lang;

        /**
         * @var Skin
         */
        private $skin;

        /**
         * Constructor
         * @param $context IContextSource Context to inherit from
         */
        public function __construct( IContextSource $context ) {
                $this->setContext( $context );
        }

        /**
         * Set the WebRequest object
         *
         * @param $r WebRequest object
         */
        public function setRequest( WebRequest $r ) {
                $this->request = $r;
        }

        /**
         * Get the WebRequest object
         *
         * @return WebRequest
         */
        public function getRequest() {
                if ( !is_null( $this->request ) ) {
                        return $this->request;
                } else {
                        return $this->getContext()->getRequest();
                }
        }

        /**
         * Set the Title object
         *
         * @param $t Title object
         */
        public function setTitle( Title $t ) {
                $this->title = $t;
        }

        /**
         * Get the Title object
         *
         * @return Title
         */
        public function getTitle() {
                if ( !is_null( $this->title ) ) {
                        return $this->title;
                } else {
                        return $this->getContext()->getTitle();
                }
        }

        /**
         * Check whether a WikiPage object can be get with getWikiPage().
         * Callers should expect that an exception is thrown from getWikiPage()
         * if this method returns false.
         *
         * @since 1.19
         * @return bool
         */
        public function canUseWikiPage() {
                if ( $this->wikipage !== null ) {
                        return true;
                } elseif ( $this->title !== null ) {
                        return $this->title->canExist();
                } else {
                        return $this->getContext()->canUseWikiPage();
                }
        }

        /**
         * Set the WikiPage object
         *
         * @since 1.19
         * @param $p WikiPage object
         */
        public function setWikiPage( WikiPage $p ) {
                $this->wikipage = $p;
        }

        /**
         * Get the WikiPage object.
         * May throw an exception if there's no Title object set or the Title object
         * belongs to a special namespace that doesn't have WikiPage, so use first
         * canUseWikiPage() to check whether this method can be called safely.
         *
         * @since 1.19
         * @return WikiPage
         */
        public function getWikiPage() {
                if ( !is_null( $this->wikipage ) ) {
                        return $this->wikipage;
                } else {
                        return $this->getContext()->getWikiPage();
                }
        }

        /**
         * Set the OutputPage object
         *
         * @param $o OutputPage
         */
        public function setOutput( OutputPage $o ) {
                $this->output = $o;
        }

        /**
         * Get the OutputPage object
         *
         * @return OutputPage object
         */
        public function getOutput() {
                if ( !is_null( $this->output ) ) {
                        return $this->output;
                } else {
                        return $this->getContext()->getOutput();
                }
        }

        /**
         * Set the User object
         *
         * @param $u User
         */
        public function setUser( User $u ) {
                $this->user = $u;
        }

        /**
         * Get the User object
         *
         * @return User
         */
        public function getUser() {
                if ( !is_null( $this->user ) ) {
                        return $this->user;
                } else {
                        return $this->getContext()->getUser();
                }
        }

        /**
         * Set the Language object
         *
         * @deprecated 1.19 Use setLanguage instead
         * @param $l Mixed Language instance or language code
         */
        public function setLang( $l ) {
                wfDeprecated( __METHOD__, '1.19' );
                $this->setLanguage( $l );
        }

        /**
         * Set the Language object
         *
         * @param $l Mixed Language instance or language code
         * @since 1.19
         */
        public function setLanguage( $l ) {
                if ( $l instanceof Language ) {
                        $this->lang = $l;
                } elseif ( is_string( $l ) ) {
                        $l = RequestContext::sanitizeLangCode( $l );
                        $obj = Language::factory( $l );
                        $this->lang = $obj;
                } else {
                        throw new MWException( __METHOD__ . " was passed an invalid type of data." );
                }
        }

        /**
         * @deprecated 1.19 Use getLanguage instead
         * @return Language
         */
        public function getLang() {
                wfDeprecated( __METHOD__, '1.19' );
                $this->getLanguage();
        }

        /**
         * Get the Language object
         *
         * @return Language
         * @since 1.19
         */
        public function getLanguage() {
                if ( !is_null( $this->lang ) ) {
                        return $this->lang;
                } else {
                        return $this->getContext()->getLanguage();
                }
        }

        /**
         * Set the Skin object
         *
         * @param $s Skin
         */
        public function setSkin( Skin $s ) {
                $this->skin = clone $s;
                $this->skin->setContext( $this );
        }

        /**
         * Get the Skin object
         *
         * @return Skin
         */
        public function getSkin() {
                if ( !is_null( $this->skin ) ) {
                        return $this->skin;
                } else {
                        return $this->getContext()->getSkin();
                }
        }

}