View layer pattern where you only present what you have been given is fine and all, but how do you know what is available? Is there a "list all defined variables" functionality in TWIG? Is there a way to dump a variable?
The solution I found by searching for it was to define a function where I can use my existing php debug tools by injecting a function, but all references I have found to that includes these nice two lines of code, but nowhere is it specified where to place them. Going by the fact that they need a $loader variable defined, I tried /app/config/autoload.php but the $loader there was the wrong kind. Where do I place the php code for adding a twig function?
As of Twig 1.5, the correct answer is to use the dump function. It is fully documented in the Twig documentation. Here is the documentation to enable this inside Symfony.
{{ dump(user) }}
You can use the debug
tag, which is documented here.
{% debug expression.varname %}
Edit: As of Twig 1.5, this has been deprecated and replaced with the new dump
function (note, it's now a function and no longer a tag). See also: The accepted answer above.
Unknown tag name "debug"
, extend your configuration (either in the global config.yml
or config_dev.yml
) as described here: github.com/symfony/symfony-docs/issues/455#issuecomment-1884861
If you are in an environment where you can't use the dump
function (ex: opencart), you can try:
{{ my_variable | json_encode(constant('JSON_PRETTY_PRINT')) }}
So I got it working, partly a bit hackish:
Set twig: debug: 1 in app/config/config.yml Add this to config_dev.yml services: debug.twig.extension: class: Twig_Extensions_Extension_Debug tags: [{ name: 'twig.extension' }] sudo rm -fr app/cache/dev To use my own debug function instead of print_r(), I opened vendor/twig-extensions/lib/Twig/Extensions/Node/Debug.php and changed print_r( to d(
PS. I would still like to know how/where to grab the $twig environment to add filters and extensions.
twig: debug: 1
because it's inheriting this information from your front controller's environment. Otherwise you could end up in uninentionally outputting debug information in your prod environment. As long as you are working in the dev environment it is enabled by default and it's disabled in your prod environment.
If you are using Twig in your application as a component you can do this:
$twig = new Twig_Environment($loader, array(
'autoescape' => false
));
$twig->addFilter('var_dump', new Twig_Filter_Function('var_dump'));
Then in your templates:
{{ my_variable | var_dump }}
$twig = new Twig_Environment($loader, array(...
?
Dump all custom variables:
<h1>Variables passed to the view:</h1>
{% for key, value in _context %}
{% if key starts with '_' %}
{% else %}
<pre style="background: #eee">{{ key }}</pre>
{{ dump(value) }}
{% endif %}
{% endfor %}
You can use my plugin which will do that for you (an will nicely format the output):
If you are using Twig as a standalone component here's some example of how to enable debugging as it's unlikely the dump(variable) function will work straight out of the box
Standalone
This was found on the link provided by icode4food
$twig = new Twig_Environment($loader, array(
'debug' => true,
// ...
));
$twig->addExtension(new Twig_Extension_Debug());
Silex
$app->register(new \Silex\Provider\TwigServiceProvider(), array(
'debug' => true,
'twig.path' => __DIR__.'/views'
));
The complete recipe here for quicker reference (note that all the steps are mandatory):
1) when instantiating Twig, pass the debug option
$twig = new Twig_Environment(
$loader, ['debug'=>true, 'cache'=>false, /*other options */]
);
2) add the debug extension
$twig->addExtension(new \Twig_Extension_Debug());
3) Use it like @Hazarapet Tunanyan pointed out
{{ dump(MyVar) }}
or
{{ dump() }}
or
{{ dump(MyObject.MyPropertyName) }}
{{ dump() }}
doesn't work for me. PHP
chokes. Nesting level too deep I guess.
All you really need to debug
Twig templates if you're using a debugger
is an extension like this.
Then it's just a matter of setting a breakpoint and calling {{ inspect() }}
wherever you need it. You get the same info as with {{ dump() }}
but in your debugger.
Since Symfony >= 2.6, there is a nice VarDumper component, but it is not used by Twig's dump()
function.
To overwrite it, we can create an extension:
In the following implementation, do not forget to replace namespaces.
Fuz/AppBundle/Resources/config/services.yml
parameters:
# ...
app.twig.debug_extension.class: Fuz\AppBundle\Twig\Extension\DebugExtension
services:
# ...
app.twig.debug_extension:
class: %app.twig.debug_extension.class%
arguments: []
tags:
- { name: twig.extension }
Fuz/AppBundle/Twig/Extension/DebugExtension.php
<?php
namespace Fuz\AppBundle\Twig\Extension;
class DebugExtension extends \Twig_Extension
{
public function getFunctions()
{
return array (
new \Twig_SimpleFunction('dump', array('Symfony\Component\VarDumper\VarDumper', 'dump')),
);
}
public function getName()
{
return 'FuzAppBundle:Debug';
}
}
For debugging Twig templates you can use the debug statement.
https://i.stack.imgur.com/BqaXa.jpg
There you can set the debug setting explicitely.
Unknown tag name "debug"
error.
You can edit
/vendor/twig/twig/lib/Twig/Extension/Debug.php
and change the var_dump()
functions to \Doctrine\Common\Util\Debug::dump()
As most good PHP programmers like to use XDebug to actually step through running code and watch variables change in real-time, using dump()
feels like a step back to the bad old days.
That's why I made a Twig Debug extension and put it on Github.
https://github.com/delboy1978uk/twig-debug
composer require delboy1978uk/twig-debug
Then add the extension. If you aren't using Symfony, like this:
<?php
use Del\Twig\DebugExtension;
/** @var $twig Twig_Environment */
$twig->addExtension(new DebugExtension());
If you are, like this in your services YAML config:
twig_debugger:
class: Del\Twig\DebugExtension
tags:
- { name: twig.extension }
Once registered, you can now do this anywhere in a twig template:
{{ breakpoint() }}
Now, you can use XDebug, execution will pause, and you can see all the properties of both the Context and the Environment.
Have fun! :-D
you can use dump function and print it like this
{{ dump(MyVar) }}
but there is one nice thing too, if you don't set any argument to dump function, it will print all variables are available, like
{{ dump() }}
Success story sharing
{{ dump() }}
to dump all variables, It return a blank page. Is there any other way to dump a variable ?<script>console.log({{ _context | json_encode | raw }});</script>
. Hope this can helpdump()
in Twig is just a blank screen check your server error logs, it's often a memory exhausted issue