How can I make kint() load faster when debugging twig templates?

Question

I've seen quite a bit of discussion about how kint() from the Devel module is difficult to work with because it maxes out PHP memory limits and makes the browser drag. I've heard some thoughts on improving its speed by limiting the number of levels. For example, in settings.php, you can do the following:

require_once DRUPAL_ROOT . '/modules/contrib/devel/kint/kint/Kint.class.php';
Kint::$maxLevels = 3;

Any other ways to improve the speed of kint()?

Answer 1

There are two other ways other users have mentioned for setting the max output levels in addition to the settings.php method mentioned in the question, plus a couple other ideas below:

1. Create a /modules/contrib/devel/kint/kint/config.php file and add / modify the line $_kintSettings['maxLevels'] = 3; (by @mdrummond on Slack)

2. In a preprocess function, add the following: (by @thpoul on Slack)

   kint_require();
   Kint::$maxLevels = 3;
   

3. Be sure to never click the + sign, that shows the entire tree. Click the block instead. You can click the right arrow to open the output in a new window for easier viewing (like when the output is in a block). (by @cwightrun on Slack)

4. Instead of using kint(), create a preprocess function and use a debugger to explore the variables. (by @danny_englander on Slack)

5. Pass kint() a specific variable instead of making it roll through the whole tree (by @No Sssweat below).

6. If you just need to know what variables exist, you can just view the keys by doing a {% for key, value in _context %} loop (by @mortendk below)

Answer 2

Kint is not the only library that you can use for debbuging variables and twig templates.

I suggest to use Symfony var-dumper that IMHO is one of the most powerful lib for debuging variables. Symfony var-dumper is integrated with latest version of devel module (see this issue in the devel issue queue Add a basic symfony var-dumper integration)

For use var-dumper with devel

• download and install devel module
• install var-dumper via composer (composer require symfony/var-dumper)
• go to devel settings page and set var-dumper as the default dumper
• use {{ devel_dump() }} or {{ kpr() }} or {{ dpm() }} instead of {{ kint() }} for debug variables in twig templates

Answer 3

FYI, as of Devel v3, you'll need to make two updates if you use the top method suggested by @chrisshattuck

1. Go to admin/config/development/devel?q=/admin/config/development/devel
2. Make sure "Kint" is selected.
3. To override the max depth, go to settings.local.php and update the max_depth variable.

  include_once(DRUPAL_ROOT . './../vendor/kint-php/kint/src/Kint.php');
  if (class_exists('Kint')) {
    Kint::$max_depth = 4;
   }  

Answer 4

Here is another tip:

Instead of using {{ kint() }} which will return everything, you can be more specific by passing the variable that you need; thus, it will load faster.

For example: In node--[type].html.twig you can pass the content variable to kint:

{{ kint(content) }}

If you know the name of the field, you can be even more specific:

{{ kint(content.field_name['#items'].getValue()) }}

This will only return the value(s) of field name.

Answer 5

instead of using kint you can do this little trick instead just to get an idea of whats in there

node.html.twig

<ol>
{% for key, value in _context  %}
<li>{{ key }} </li>
 {% if loop.index == 2 %}}
    <pre>{{ dump( value ) }}</pre>
{% endif %}
{% endfor %}
</ol>

yes it dont gives all the love that kint wants to show you, but at least you get the names etc out

Answer 6

When it is impossible to get the HTML view or it is too slow to load the kint output.

I will serialize the variable and save it with

\Drupal::logger('custom debug')->notice($string);

Then I will copy it to unserialize.com and choose Krumo display....

Answer 7

To limit the number of levels from Kint, you go to your local.settings.php or settings.php and use

$_kintSettings['maxLevels'] = 3;

Answer 8

Adding $GLOBALS['_kint_settings']['maxLevels'] = 4; in your settings.local.php should do the trick. Feel free to change the number of levels here.