File: /var/www/delta/wp-content/themes/delta/vendor/timber/timber/docs/guides/debugging.md
---
title: "Debugging"
menu:
main:
parent: "guides"
---
## Enable debugging
To use debugging, the constant `WP_DEBUG` needs to be set to `true`.
**wp-config.php**
```php
define( 'WP_DEBUG', true );
```
## Using Twig’s native functions
Twig includes a `dump` function that can output the properties of an object.
**Twig**
```twig
{{ dump(post) }}
```
Which will give you:
You can also dump _everything_ sent to your template (all the contents of `$context` that were passed to the Twig file) via:
```twig
{{ dump() }}
```
This will give you something like:
## Formatted output
For a highlighted output like you see it above, you need to have [xDebug](https://xdebug.org/) enabled in your local development environment. With some environments like MAMP, enabling it is as easy as ticking a checkbox and restarting the server. Other times, it might be more complex.
An easier solution is to use the [Timber Dump Extension](https://github.com/nlemoine/timber-dump-extension), which will make use of the Symfony VarDumper component to generate output like this when using `{{ dump() }}` in Twig:
It also works in PHP. Instead of using `var_dump` or `print_r`, you will use `dump()` as well:
```php
dump( $post );
```
## Commented Twig includes
Sometimes it’s difficult to know which Twig file generated a certain output. Thankfully, there’s the [Timber Commented Include](https://github.com/djboris88/timber-commented-include) extension. It will generate HTML comments that indicate where a template starts and where it ends:
```html
<!-- Begin output of "partials/navigation.twig" -->
<nav class="navigation">...</nav>
<!-- / End output of "partials/navigation.twig" -->).
```
The extension is only active when `WP_DEBUG` is set to `true`.
## Set breakpoints in Twig
### Twig breakpoints in PhpStorm
With PhpStorm, you can [set breakpoints right in your Twig files](https://blog.jetbrains.com/phpstorm/2019/05/twig-and-blade-templates-debugging-2/). To make it work, you need to enable the caching of Twig files:
**functions.php**
```php
Timber::$twig_cache = true;
```
Then, you need to reference the path to the cached files in ***Settings/Preferences*** → ***Languages & Frameworks*** → ***PHP*** → ***Debug*** → ***Templates***. If you’ve installed Timber through Composer, the path will be `vendor/timber/timber/cache/`.
Remember that you can set the location of the cache files through the `timber/cache/location` filter:
```php
add_filter( 'timber/cache/location', function() {
return '/absolute/path/to/your/cached/twig/files';
} );
```
### Twig breakpoints in other IDEs
Other IDEs don’t allow you to set breakpoints in your PHP code. You can try out the [AjglBreakpointTwigExtension](https://github.com/ajgarlag/AjglBreakpointTwigExtension) extension, that allows you to set breakpoints and inspect environment and context variables.
Install it as a dev-dependency:
```
composer require ajgl/breakpoint-twig-extension --dev
```
And then add it to Timber’s Twig environment:
**functions.php**
```php
add_filter( 'timber/twig', function( \Twig\Environment $twig ) {
if ( defined( 'WP_DEBUG' ) && WP_DEBUG
&& class_exists( 'Ajgl\Twig\Extension\BreakpointExtension' )
) {
$twig->addExtension( new Ajgl\Twig\Extension\BreakpointExtension() );
}
return $twig;
} );
```
Finally, you can set a breakpoint anywhere in your Twig file:
```twig
<nav>
{{ breakpoint() }}
</nav>
```
## Timber Debugger
The [**Timber Debugger**](https://github.com/djboris88/timber-debugger) package includes all three extensions mentioned above: the [Timber Dump](https://github.com/nlemoine/timber-dump-extension) extension, the [Timber Commented Include](https://github.com/djboris88/timber-commented-include) extension and the [Twig Breakpoints](https://github.com/ajgarlag/AjglBreakpointTwigExtension) extension.
## Using Timber Debug Bar plugin
There’s a [Timber add-on](http://wordpress.org/plugins/debug-bar-timber/) for the [WordPress debug bar](https://wordpress.org/plugins/debug-bar/).
**Warning:** this currently requires PHP 5.4.
## Using (Legacy) Timber Filters
You can also use some quick filters on an object. These are legacy and will be removed in favor of using Twig's built-in functionality. However, these do not require that `WP_DEBUG` be turned on.
### print_r
Passes the variable to PHP’s `print_r` function.
```twig
{{ post|print_r }}
```
### get_class
This filter answers the question: What type of object am I working with? It passes a variable to PHP’s `get_class` function.
```twig
{{ post|get_class }}
```
It will output something like `TimberPost` or your custom wrapper object.