Learning a new system usually means learning about its little quirks. Drupal 8 has its fair share of quirks. Here are some quick tips that I have learned in the past few months working on my first Drupal 8 project.
Suppose you need to get the last time an item in a table was edited. You can build a dynamic query and, instead of using fields(), you'd use addExpression() like so:
Now you will get the highest timestamp.
$timestamp = $query->execute()->fetchField();
$entity->field_name will return null if the field does not exist while
$entity->get('field_name') will throw an Exception. Sometimes you'll want one behavior over another so keep that in mind.
I almost went mad looking for an answer until I dived into the code and learned about
#wrapper_attributes. Just add this to your item list render array and you're good to go. It will apply those attributes to each
<li> tag within your item list.
If you need to add a value to a multivalue field in an entity, you can use
appendItem() to get the job done.
Over the coming weeks, I or any of my fellow developers here at Rootstack will be posting quick tips for other developers new to Drupal 8. I'm sure you will learn a thing or two or, at the very least, we will save you from a mild headache.