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lib/pkp/classes/oai/OAIUtils.php

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+<?php
+
+/**
+ * @file classes/oai/OAIUtils.php
+ *
+ * Copyright (c) 2014-2021 Simon Fraser University
+ * Copyright (c) 2000-2021 John Willinsky
+ * Distributed under the GNU GPL v3. For full terms see the file docs/COPYING.
+ *
+ * @class OAI
+ *
+ * @ingroup oai
+ *
+ * @see OAIDAO
+ *
+ * @brief Utility functions used by OAI related classes.
+ */
+
+namespace PKP\oai;
+
+use Transliterator;
+
+class OAIUtils
+{
+    private static $TO_ASCII;
+    private static $NOT_IN_URI_NON_RESERVED_CHARS = '/[^A-Za-z0-9\-_\.!~*\'()]/';
+
+    public static function init()
+    {
+        self::$TO_ASCII = Transliterator::createFromRules(':: Any-Latin; :: Latin-ASCII; :: NFD; :: [:Nonspacing Mark:] Remove; :: NFC;', Transliterator::FORWARD);
+    }
+
+    /**
+     * Return a UTC-formatted datestamp from the specified UNIX timestamp.
+     *
+     * @param int $timestamp *nix timestamp (if not used, the current time is used)
+     * @param bool $includeTime include both the time and date
+     *
+     * @return string UTC datestamp
+     */
+    public static function UTCDate($timestamp = 0, $includeTime = true)
+    {
+        $format = 'Y-m-d';
+        if ($includeTime) {
+            $format .= "\TH:i:s\Z";
+        }
+
+        if ($timestamp == 0) {
+            return gmdate($format);
+        } else {
+            return gmdate($format, $timestamp);
+        }
+    }
+
+    /**
+     * Returns a UNIX timestamp from a UTC-formatted datestamp.
+     * Returns the string "invalid" if datestamp is invalid,
+     * or "invalid_granularity" if unsupported granularity.
+     *
+     * @param string $date UTC datestamp
+     * @param string $requiredGranularity Datestamp granularity to require (default: not checked)
+     *
+     * @return int|string timestamp
+     */
+    public static function UTCtoTimestamp($date, $requiredGranularity = null)
+    {
+        // FIXME Has limited range (see http://php.net/strtotime)
+        if (preg_match("/^\d\d\d\d\-\d\d\-\d\d$/", $date)) {
+            // Match date
+            $time = strtotime("{$date} UTC");
+            return ($time != -1) ? $time : 'invalid';
+        } elseif (preg_match("/^(\d\d\d\d\-\d\d\-\d\d)T(\d\d:\d\d:\d\d)Z$/", $date, $matches)) {
+            // Match datetime
+            // FIXME
+            $date = "{$matches[1]} {$matches[2]}";
+            if ($requiredGranularity && $requiredGranularity != 'YYYY-MM-DDThh:mm:ssZ') {
+                return 'invalid_granularity';
+            } else {
+                $time = strtotime("{$date} UTC");
+                return ($time != -1) ? $time : 'invalid';
+            }
+        } else {
+            return 'invalid';
+        }
+    }
+
+
+    /**
+     * Clean input variables (by reference).
+     *
+     * @param mixed $data request parameter(s)
+     */
+    public static function prepInput(&$data)
+    { // REFERENCE REQUIRED
+        if (!is_array($data)) {
+            $data = urldecode($data);
+        } else {
+            foreach ($data as $k => $v) {
+                if (is_array($data[$k])) {
+                    self::prepInput($data[$k]);
+                } else {
+                    $data[$k] = urldecode($v);
+                }
+            }
+        }
+        return $data;
+    }
+
+    /**
+     * Prepare variables for output (by reference).
+     * Data is assumed to be UTF-8 encoded (FIXME?)
+     *
+     * @param mixed $data output parameter(s)
+     *
+     * @return mixed cleaned output parameter(s)
+     */
+    public static function prepOutput(&$data)
+    { // REFERENCE REQUIRED
+        if (!is_array($data)) {
+            $data = htmlspecialchars($data);
+        } else {
+            foreach ($data as $k => $v) {
+                if (is_array($data[$k])) {
+                    self::prepOutput($data[$k]);
+                } else {
+                    // FIXME FIXME FIXME
+                    $data[$k] = htmlspecialchars($v);
+                }
+            }
+        }
+        return $data;
+    }
+
+    /**
+     * Parses string $string into an associate array $array.
+     * Acts like parse_str($string, $array) except duplicate
+     * variable names in $string are converted to an array.
+     *
+     * @param array $array of parsed parameters
+     */
+    public static function parseStr($string, &$array)
+    {
+        $pairs = explode('&', $string);
+        foreach ($pairs as $p) {
+            $vars = explode('=', $p);
+            if (!empty($vars[0]) && isset($vars[1])) {
+                $key = $vars[0];
+                $value = join('=', array_splice($vars, 1));
+
+                if (!isset($array[$key])) {
+                    $array[$key] = $value;
+                } elseif (is_array($array[$key])) {
+                    array_push($array[$key], $value);
+                } else {
+                    $array[$key] = [$array[$key], $value];
+                }
+            }
+        }
+    }
+
+    /**
+     * Valid characters in setSpec [1] are URI unreserved characters [2]
+     * Create a valid string by
+     *  - transliterating all non-Latin characters
+     *  - stripping all diacritics
+     *  - dropping any remaining invalid characters
+     *
+     * [1] https://www.openarchives.org/OAI/2.0/openarchivesprotocol.htm#Set
+     * [2] http://www.ietf.org/rfc/rfc2396.txt
+     *
+     */
+    public static function toValidSetSpec(string $string): string
+    {
+        $t = self::$TO_ASCII->transliterate($string);
+        return preg_replace(self::$NOT_IN_URI_NON_RESERVED_CHARS, '', $t);
+    }
+}
+OAIUtils::init();
+
+if (!PKP_STRICT_MODE) {
+    class_alias('\PKP\oai\OAIUtils', '\OAIUtils');
+}