add lang class

classes/lang.class.php

+<?php
+
+
+class lang
+{
+
+    /**
+     * Language code with 2 digits
+     * @var string
+     */
+    protected string $sLang = 'en';
+
+    /**
+     * Array with all translation texts of a language
+     * @var array
+     */
+    protected array $aLang = [];
+
+    /**
+     * Constructor
+     * @param string $sLang  optional: language to set
+     */
+    public function __construct(string $sLang='')
+    {
+        if($sLang){
+            $this->setLang($sLang);
+        }
+
+    }
+
+    /**
+     * Set a Language; it loads a JSON file with translations
+     * @param string $sLanguageCode  2 digit language code
+     * @return bool
+     */
+    public function setLang(string $sLanguageCode = ''): bool
+    {
+        $sLlangfile = dirname((__DIR__))."/lang/$sLanguageCode.json";
+        if (!file_exists($sLlangfile)) {
+            new Exception("ERROR: Language file $sLlangfile does not exist.");
+            return false;
+        }
+        $aTmp = json_decode(file_get_contents($sLlangfile), 1);
+        if(!is_array($aTmp)){
+            new Exception("ERROR: Language file $sLlangfile is not valid JSON.");
+            return false;
+        }
+        $this->aLang = $aTmp;
+        $this->sLang = $sLanguageCode;
+        return true;
+    }
+
+    /**
+     * Get the translated text for a given key
+     * @param string $s
+     * @return string
+     */
+    public function t($sKeyword): string
+    {
+        return $this->aLang[$sKeyword] ?? "MISS [$sKeyword]";
+    }
+}
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