Additional Configuration
========================

Yii Twig extension allows you to define your own syntax and bring regular helper classes into templates. Let's review
configuration options.

## Globals

You can add global helpers or values via the application configuration's `globals` variable. You can define both Yii
helpers and your own variables there:

```php
'globals' => [
    'html' => ['class' => \yii\helpers\Html::class],
    'name' => 'Carsten',
    'GridView' => ['class' => \yii\grid\GridView::class],
],
```

Once configured, in your template you can use the globals in the following way:

```twig
Hello, {{name}}! {{ html.a('Please login', 'site/login') | raw }}.

{{ GridView.widget({'dataProvider' : provider}) | raw }}
```

## Functions

You can define additional functions like the following:

```php
'functions' => [
    'rot13' => 'str_rot13',
    'truncate' => '\yii\helpers\StringHelper::truncate',
    new \Twig_SimpleFunction('rot14', 'str_rot13'),
    new \Twig_SimpleFunction('add_*', function ($symbols, $val) {
        return $val . $symbols;
    }, ['is_safe' => ['html']]),
    'callable_add_*' => function ($symbols, $val) {
        return $val . $symbols;
    },
    'sum' => function ($a, $b) {
        return $a + $b;
    }
],
```

In template they could be used like the following:

```twig
{{ rot13('test') }}
{{ truncate(post.text, 100) }}
{{ rot14('test') }}
{{ add_42('answer') }}
{{ callable_add_42('test') }}
{{ sum(1, 2) }}
```

## Filters

Additional filters may be added via the application configuration's `filters` option:

```php
'filters' => [
    'jsonEncode' => '\yii\helpers\Json::htmlEncode',
    new \Twig_SimpleFilter('rot13', 'str_rot13'),
    new \Twig_SimpleFilter('add_*', function ($symbols, $val) {
        return $val . $symbols;
    }, ['is_safe' => ['html']]),
    'callable_rot13' => function($string) {
        return str_rot13($string);
    },
    'callable_add_*' => function ($symbols, $val) {
        return $val . $symbols;
    }
],
```

Then in the template you can apply filter using the following syntax:

```twig
{{ model|jsonEncode }}
{{ 'test'|rot13 }}
{{ 'answer'|add_42 }}
{{ 'test'|callable_rot13 }}
{{ 'answer'|callable_add_42 }}
```

## Paths

Additional paths may be added via the application configuration's `twigFallbackPaths` option:

```php
'twigFallbackPaths' => [
    'layouts' => '@app/views/layouts' //it is possible to use yii2-alises
]
```

Then they could be used in a template:

```twig
{% extends '@layouts/main.twig %}
```

## Profiling

To include [twig-profile](https://twig.symfony.com/doc/2.x/api.html#profiler-extension) data in trace log you need to add the extension

```php
'extensions' => [
    \yii\twig\Profile::class
]
```

Profile writes log only debug mode.

Using a profile affects performance.