Fix various compatibility issues with PHP 8

libs/ical/Util/ComponentUtil.php

@@ -0,0 +1,62 @@
+<?php
+
+/*
+ * This file is part of the eluceo/iCal package.
+ *
+ * (c) Markus Poerschke <markus@eluceo.de>
+ *
+ * This source file is subject to the MIT license that is bundled
+ * with this source code in the file LICENSE.
+ */
+
+namespace Eluceo\iCal\Util;
+
+class ComponentUtil
+{
+    /**
+     * Folds a single line.
+     *
+     * According to RFC 5545, all lines longer than 75 characters should be folded
+     *
+     * @see https://tools.ietf.org/html/rfc5545#section-5
+     * @see https://tools.ietf.org/html/rfc5545#section-3.1
+     *
+     * @param string $string
+     *
+     * @return array
+     */
+    public static function fold($string)
+    {
+        $lines = [];
+
+        if (function_exists('mb_strcut')) {
+            while (strlen($string) > 0) {
+                if (strlen($string) > 75) {
+                    $lines[] = mb_strcut($string, 0, 75, 'utf-8');
+                    $string = ' ' . mb_strcut($string, 75, strlen($string), 'utf-8');
+                } else {
+                    $lines[] = $string;
+                    $string = '';
+                    break;
+                }
+            }
+        } else {
+            $array = preg_split('/(?<!^)(?!$)/u', $string);
+            $line = '';
+            $lineNo = 0;
+            foreach ($array as $char) {
+                $charLen = strlen($char);
+                $lineLen = strlen($line);
+                if ($lineLen + $charLen > 75) {
+                    $line = ' ' . $char;
+                    ++$lineNo;
+                } else {
+                    $line .= $char;
+                }
+                $lines[$lineNo] = $line;
+            }
+        }
+
+        return $lines;
+    }
+}

libs/ical/Util/DateUtil.php

@@ -0,0 +1,77 @@
+<?php
+
+/*
+ * This file is part of the eluceo/iCal package.
+ *
+ * (c) Markus Poerschke <markus@eluceo.de>
+ *
+ * This source file is subject to the MIT license that is bundled
+ * with this source code in the file LICENSE.
+ */
+
+namespace Eluceo\iCal\Util;
+
+class DateUtil
+{
+    public static function getDefaultParams(\DateTimeInterface $dateTime = null, $noTime = false, $useTimezone = false, $timezoneString = '')
+    {
+        $params = [];
+
+        if ($useTimezone && $noTime === false) {
+            $timeZone = $timezoneString === '' ? $dateTime->getTimezone()->getName() : $timezoneString;
+            $params['TZID'] = $timeZone;
+        }
+
+        if ($noTime) {
+            $params['VALUE'] = 'DATE';
+        }
+
+        return $params;
+    }
+
+    /**
+     * Returns a formatted date string.
+     *
+     * @param \DateTimeInterface|null $dateTime    The DateTime object
+     * @param bool                    $noTime      Indicates if the time will be added
+     * @param bool                    $useTimezone
+     * @param bool                    $useUtc
+     *
+     * @return mixed
+     */
+    public static function getDateString(\DateTimeInterface $dateTime = null, $noTime = false, $useTimezone = false, $useUtc = false)
+    {
+        if (empty($dateTime)) {
+            $dateTime = new \DateTimeImmutable();
+        }
+
+        // Only convert the DateTime to UTC if there is a time present. For date-only the
+        // timezone is meaningless and converting it might shift it to the wrong date.
+        // Do not convert DateTime to UTC if a timezone it specified, as it should be local time.
+        if (!$noTime && $useUtc && !$useTimezone) {
+            $dateTime = clone $dateTime;
+            $dateTime = $dateTime->setTimezone(new \DateTimeZone('UTC'));
+        }
+
+        return $dateTime->format(self::getDateFormat($noTime, $useTimezone, $useUtc));
+    }
+
+    /**
+     * Returns the date format that can be passed to DateTime::format().
+     *
+     * @param bool $noTime      Indicates if the time will be added
+     * @param bool $useTimezone
+     * @param bool $useUtc
+     *
+     * @return string
+     */
+    public static function getDateFormat($noTime = false, $useTimezone = false, $useUtc = false)
+    {
+        // Do not use UTC time (Z) if timezone support is enabled.
+        if ($useTimezone || !$useUtc) {
+            return $noTime ? 'Ymd' : 'Ymd\THis';
+        }
+
+        return $noTime ? 'Ymd' : 'Ymd\THis\Z';
+    }
+}