Allow to generate multiple labels at once (multiple pages in 1 PDF file).

src/Services/Misc/RangeParser.php

@@ -0,0 +1,94 @@
+<?php
+/**
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ * Copyright (C) 2019 - 2020 Jan Böhmer (https://github.com/jbtronics)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+namespace App\Services\Misc;
+
+/**
+ * This Parser allows to parse number ranges like 1-3, 4, 5
+ */
+class RangeParser
+{
+    /**
+     * Converts the given range string to an array of all numbers in the given range.
+     * @param  string  $range A range string like '1-3, 5, 6'
+     * @return int[] An array with all numbers from the range (e.g. [1, 2, 3, 5, 6]
+     */
+    public function parse(string $range_str): array
+    {
+        //Normalize number separator (we allow , and ;):
+        $range_str = str_replace(';', ',', $range_str);
+
+        $numbers = explode(',', $range_str);
+        $ranges = [];
+        foreach ($numbers as $number) {
+            $number = trim($number);
+            //Extract min / max if token is a range
+            $matches = [];
+            if (preg_match('/^(-?\s*\d+)\s*-\s*(-?\s*\d+)$/', $number, $matches)) {
+                $ranges[] = $this->generateMinMaxRange($matches[1], $matches[2]);
+            } elseif (is_numeric($number)) {
+                $ranges[] = [(int) $number];
+            } elseif (empty($number)) { //Allow empty tokens
+                continue;
+            } else {
+                throw new \InvalidArgumentException('Invalid range encoutered: ' . $number);
+            }
+        }
+
+        //Flatten ranges array
+        return array_merge([], ...$ranges);
+    }
+
+    /**
+     * Checks if the given string is a valid range.
+     * @param  string  $range_str The string that should be checked
+     * @return bool True if the string is valid, false if not.
+     */
+    public function isValidRange(string $range_str): bool
+    {
+        try {
+            $this->parse($range_str);
+            return true;
+        } catch (\InvalidArgumentException $exception) {
+            return false;
+        }
+    }
+
+    protected function generateMinMaxRange(string $min, string $max): array
+    {
+        $min = (int) $min;
+        $max = (int) $max;
+
+        //Ensure that $max > $min
+        if ($min > $max) {
+            $a = $max;
+            $max = $min;
+            $min = $a;
+        }
+
+        $tmp = [];
+        while ($min <= $max) {
+            $tmp[] = $min;
+            $min++;
+        };
+
+        return $tmp;
+    }
+}