PHPSessionHandler: Implement SessionHandlerInterface

[mediawiki.git] / includes / libs / StatusValue.php

<?php
/**
 * 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
 */

/**
 * Generic operation result class
 * Has warning/error list, boolean status and arbitrary value
 *
 * "Good" means the operation was completed with no warnings or errors.
 *
 * "OK" means the operation was partially or wholly completed.
 *
 * An operation which is not OK should have errors so that the user can be
 * informed as to what went wrong. Calling the fatal() function sets an error
 * message and simultaneously switches off the OK flag.
 *
 * The recommended pattern for Status objects is to return a StatusValue
 * unconditionally, i.e. both on success and on failure -- so that the
 * developer of the calling code is reminded that the function can fail, and
 * so that a lack of error-handling will be explicit.
 *
 * The use of Message objects should be avoided when serializability is needed.
 *
 * @since 1.25
 */
class StatusValue {
        /** @var bool */
        protected $ok = true;
        /** @var array */
        protected $errors = array();

        /** @var mixed */
        public $value;
        /** @var array Map of (key => bool) to indicate success of each part of batch operations */
        public $success = array();
        /** @var int Counter for batch operations */
        public $successCount = 0;
        /** @var int Counter for batch operations */
        public $failCount = 0;

        /**
         * Factory function for fatal errors
         *
         * @param string|MessageSpecifier $message Message key or object
         * @return Status
         */
        public static function newFatal( $message /*, parameters...*/ ) {
                $params = func_get_args();
                $result = new static();
                call_user_func_array( array( &$result, 'fatal' ), $params );
                return $result;
        }

        /**
         * Factory function for good results
         *
         * @param mixed $value
         * @return Status
         */
        public static function newGood( $value = null ) {
                $result = new static();
                $result->value = $value;
                return $result;
        }

        /**
         * Returns whether the operation completed and didn't have any error or
         * warnings
         *
         * @return bool
         */
        public function isGood() {
                return $this->ok && !$this->errors;
        }

        /**
         * Returns whether the operation completed
         *
         * @return bool
         */
        public function isOK() {
                return $this->ok;
        }

        /**
         * @return mixed
         */
        public function getValue() {
                return $this->value;
        }

        /**
         * Get the list of errors
         *
         * Each error is a (message:string or MessageSpecifier,params:array) map
         *
         * @return array
         */
        public function getErrors() {
                return $this->errors;
        }

        /**
         * Change operation status
         *
         * @param bool $ok
         */
        public function setOK( $ok ) {
                $this->ok = $ok;
        }

        /**
         * Change operation resuklt
         *
         * @param bool $ok Whether the operation completed
         * @param mixed $value
         */
        public function setResult( $ok, $value = null ) {
                $this->ok = $ok;
                $this->value = $value;
        }

        /**
         * Add a new warning
         *
         * @param string|MessageSpecifier $message Message key or object
         */
        public function warning( $message /*, parameters... */ ) {
                $this->errors[] = array(
                        'type' => 'warning',
                        'message' => $message,
                        'params' => array_slice( func_get_args(), 1 )
                );
        }

        /**
         * Add an error, do not set fatal flag
         * This can be used for non-fatal errors
         *
         * @param string|MessageSpecifier $message Message key or object
         */
        public function error( $message /*, parameters... */ ) {
                $this->errors[] = array(
                        'type' => 'error',
                        'message' => $message,
                        'params' => array_slice( func_get_args(), 1 )
                );
        }

        /**
         * Add an error and set OK to false, indicating that the operation
         * as a whole was fatal
         *
         * @param string|MessageSpecifier $message Message key or object
         */
        public function fatal( $message /*, parameters... */ ) {
                $this->errors[] = array(
                        'type' => 'error',
                        'message' => $message,
                        'params' => array_slice( func_get_args(), 1 )
                );
                $this->ok = false;
        }

        /**
         * Merge another status object into this one
         *
         * @param StatusValue $other Other StatusValue object
         * @param bool $overwriteValue Whether to override the "value" member
         */
        public function merge( $other, $overwriteValue = false ) {
                $this->errors = array_merge( $this->errors, $other->errors );
                $this->ok = $this->ok && $other->ok;
                if ( $overwriteValue ) {
                        $this->value = $other->value;
                }
                $this->successCount += $other->successCount;
                $this->failCount += $other->failCount;
        }

        /**
         * Returns a list of status messages of the given type
         *
         * Each entry is a map of (message:string or MessageSpecifier,params:array))
         *
         * @param string $type
         * @return array
         */
        public function getErrorsByType( $type ) {
                $result = array();
                foreach ( $this->errors as $error ) {
                        if ( $error['type'] === $type ) {
                                $result[] = $error;
                        }
                }

                return $result;
        }

        /**
         * Returns true if the specified message is present as a warning or error
         *
         * @param string|MessageSpecifier $message Message key or object to search for
         *
         * @return bool
         */
        public function hasMessage( $message ) {
                if ( $message instanceof MessageSpecifier ) {
                        $message = $message->getKey();
                }
                foreach ( $this->errors as $error ) {
                        if ( $error['message'] instanceof MessageSpecifier
                                && $error['message']->getKey() === $message
                        ) {
                                return true;
                        } elseif ( $error['message'] === $message ) {
                                return true;
                        }
                }

                return false;
        }

        /**
         * If the specified source message exists, replace it with the specified
         * destination message, but keep the same parameters as in the original error.
         *
         * Note, due to the lack of tools for comparing IStatusMessage objects, this
         * function will not work when using such an object as the search parameter.
         *
         * @param IStatusMessage|string $source Message key or object to search for
         * @param IStatusMessage|string $dest Replacement message key or object
         * @return bool Return true if the replacement was done, false otherwise.
         */
        public function replaceMessage( $source, $dest ) {
                $replaced = false;

                foreach ( $this->errors as $index => $error ) {
                        if ( $error['message'] === $source ) {
                                $this->errors[$index]['message'] = $dest;
                                $replaced = true;
                        }
                }

                return $replaced;
        }

        /**
         * @return string
         */
        public function __toString() {
                $status = $this->isOK() ? "OK" : "Error";
                if ( count( $this->errors ) ) {
                        $errorcount = "collected " . ( count( $this->errors ) ) . " error(s) on the way";
                } else {
                        $errorcount = "no errors detected";
                }
                if ( isset( $this->value ) ) {
                        $valstr = gettype( $this->value ) . " value set";
                        if ( is_object( $this->value ) ) {
                                $valstr .= "\"" . get_class( $this->value ) . "\" instance";
                        }
                } else {
                        $valstr = "no value set";
                }
                $out = sprintf( "<%s, %s, %s>",
                        $status,
                        $errorcount,
                        $valstr
                );
                if ( count( $this->errors ) > 0 ) {
                        $hdr = sprintf( "+-%'-4s-+-%'-25s-+-%'-40s-+\n", "", "", "" );
                        $i = 1;
                        $out .= "\n";
                        $out .= $hdr;
                        foreach ( $this->errors as $error ) {
                                if ( $error['message'] instanceof MessageSpecifier ) {
                                        $key = $error['message']->getKey();
                                        $params = $error['message']->getParams();
                                } elseif ( $error['params'] ) {
                                        $key = $error['message'];
                                        $params = $error['params'];
                                } else {
                                        $key = $error['message'];
                                        $params = array();
                                }

                                $out .= sprintf( "| %4d | %-25.25s | %-40.40s |\n",
                                        $i,
                                        $key,
                                        implode( " ", $params )
                                );
                                $i += 1;
                        }
                        $out .= $hdr;
                }

                return $out;
        }
}