How to add a custom function to smarty extension yii2 - php

Question

i have a little problem with smarty extension for yii2.
I've created a new smarty function, and i've added the code into this file:
backend/vendor/yiisoft/yii2-smarty/src/Extension.php
public function __construct($viewRenderer, $smarty)
{
//other code
/* CUSTOM FUNCTION REGISTER */
$smarty->registerPlugin('function', 'test', [$this, 'functionTest']);
}
//this is the custom function
public function functionTest($params, $template){
return "Test custom funcion";
}
And i can use this custom function into my template like this {test} and all works fine.
Today i have update the yii2 to the 2.0.20 version, and obviously the Extension.php file was replaced, so i can't access anymore to the custom function.
My question is: How i can add a custom function for smarty in yii2?
I'll set the config array in this way:
//this is in backend/config/main.php
'view' => [
'renderers' => [
'tpl' => [
'class' => 'yii\smarty\ViewRenderer',
'pluginDirs' => ['#backend/saSmartyPlugin'],
'widgets' =>[
'functions' => [['test' => 'test'], ],
],
//'cachePath' => '#runtime/Smarty/cache',
],
],
],
and the into saSmartyPlugin folder i insert my test.php file like this:
<?php
class Test{
function functionTest($params, $template){
return "Test custom funcion";
}
}
But i get this error:
Smarty: Undefined class 'test' in register template class

Answer 1

I agree with Muhammad Omer Aslam, you should extend from backend/vendor/yiisoft/yii2-smarty/src/Extension.php in order to create Any new methods and be able to use them after update. After that you just write in your config file path to your extended class.

Answer 2

I'll find a solution thinking about #MuhammadOmerAslam and #SergheiLeonenco suggest me.
I write this answer for anyone who has this problem.
First i create my php file Test.php and i extend the Extension class of Smarty
namespace common\components;
use yii\smarty\Extension;
class Test extends Extension{
public function __construct($viewRenderer, $smarty){
parent::__construct($viewRenderer, $smarty);// call parent construct
$smarty->registerPlugin('function', 'bread', [$this, 'functionBreadcrumbs']);//register my custom function
}
//My custom function
function functionTest($params, $template){
return "Test custom funcion";
}
And i save this file into common/components/
After that i have modified my config.php file
'view' => [
'renderers' => [
'tpl' => [
'class' => 'yii\smarty\ViewRenderer',
'extensionClass' => 'common\components\Test'
],
],
],
],