Retrieve reference to content type in preprocess

Question

I have a content type (let's name it Wheel for an example) that have a field referencing an other content type (which could be Car, Motorbike, Bicycle ...). So a node named WheelMotorbikeBrand whould reference the content type Motorbike. I would like to retrieve the value of this field in a preprocess with something like $node->get('field_wheel-type') but I'm not able to obtain a value. How can I retrieve the value of my field ?

Answer 1

You get a field value:

$value = $node->field_text->value;

If the field has a property value like fields for texts, numbers or booleans usually have.

A reference field has no value property, but one for target_id. So you get the id of the referenced entity with:

$target_id = $node->field_reference->target_id;

Or the referenced entity already loaded:

$referenced_node = $node->field_reference->entity;

Which you then can use to obtain a field value from the referenced node:

$value = $referenced_node->field_text->value;

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The method ->getValue():

$values = $node->field_text->getValue();

gets an array of all properties and field items and so works also if you don't know the properties of a field or how many items it has.

Caveat: You don't find the property entity from the example above in this array, because it is computed and not stored in the database.

Answer 2

try :

$value = $node->get('field_wheel-type')->getValue();