How do I check the content of variables passed to a template file?

Question

I enabled Twig debug and I tried to debug some custom fields. However, if I try this with debug() or kint(), my application always crashes. My PHP memory size is currently 512MB; I assume that should be enough.

I realise that node is a bit too much to debug, so I tried debugging a field as in node.field_video, but that didn't work out as well.

How do I check the content of variables passed to a template file?

Answer 1

You can follow document.

To dump only the available variable keys use:

{{ dump(_context|keys) }}

In this case you can use:

{{ kint(node|keys) }}

Or you can follow topic

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

The best way: install module twig_tweak and using twig function {{drupal_dump(node)}} to dump variables.

Answer 2

Note that if your fields are inside custom blocks, and you're trying to access those fields, the syntax is slightly different. You'll want to access them this way, with a kint statement inside your custom twig file:

{{ kint(_context) }}

Inside the _context array, I found my fields were then inside the content array. So in my case, I was looking for the value of field_caption - and that was available at

{{ _context.content.field_caption.0 }}

I hope that helps someone else save some time along the way!