Add function to add any prefix (it must not contain :) for not empty …

…values.

src/Functions/Prefix.php

@@ -0,0 +1,27 @@
+<?php
+/**
+ *
+ * PHP version >= 5.6
+ *
+ * @package andydune/string-replace
+ * @link  https://github.com/AndyDune/StringReplace for the canonical source repository
+ * @license   http://www.opensource.org/licenses/mit-license.html  MIT License
+ * @author Andrey Ryzhov  <info@rznw.ru>
+ * @copyright 2018 Andrey Ryzhov
+ */
+
+
+namespace AndyDune\StringReplace\Functions;
+
+
+class Prefix
+{
+    public function __invoke($string, $prefix = '')
+    {
+        if ($string) {
+            return $prefix . $string;
+        }
+        return $string;
+    }
+
+}

src/FunctionsHolder.php

@@ -15,6 +15,7 @@
 use AndyDune\StringReplace\Functions\FunctionAbstract;
 use AndyDune\StringReplace\Functions\LeaveStringWithLength;
 use AndyDune\StringReplace\Functions\PluralStringRussian;
+use AndyDune\StringReplace\Functions\Prefix;
 use AndyDune\StringReplace\Functions\SetCommaBefore;
 use AndyDune\StringReplace\Functions\PluralStringEnglish;
 use AndyDune\StringReplace\Functions\PrintFormatted;
@@ -24,6 +25,7 @@ class FunctionsHolder
 {
     protected $functions = [
         'escape' => EscapeHtmlSpecialChars::class,
+        'prefix' => Prefix::class,
         'addcomma' => SetCommaBefore::class,
         'maxlen' => LeaveStringWithLength::class,
         'pluralrus' => PluralStringRussian::class,

test/StringReplaceTest.php

@@ -165,6 +165,23 @@ public function testPower()
         $this->assertEquals('I know words: «eat» and «sleep»', $instance->replace($string));
 
 
+        $string = 'Vegetables I have: #apple_count:prefix("apples "):addcomma(1)##orange_count:prefix("oranges "):addcomma(1)#';
+        $instance = new PowerReplace();
+        $instance->apple_count = 1;
+        $this->assertEquals('Vegetables I have: apples 1', $instance->replace($string));
+
+        $string = 'Vegetables I have: #apple_count:prefix("apples "):addcomma(1)##orange_count:prefix("oranges "):addcomma(1)#';
+        $instance = new PowerReplace();
+        $instance->orange_count = 1;
+        $this->assertEquals('Vegetables I have: oranges 1', $instance->replace($string));
+
+        $string = 'Vegetables I have: #apple_count:prefix("apples "):addcomma(1)##orange_count:prefix("oranges "):addcomma(1)#';
+        $instance = new PowerReplace();
+        $instance->orange_count = 1;
+        $instance->apple_count = 2;
+        $this->assertEquals('Vegetables I have: apples 2, oranges 1', $instance->replace($string));
+
+
     }
 
     public function testPowerAddCustomFunction()