Retrieve hidden field value & expose to .tpl file

Question

I have a field collection set up for fields that make up a slider, one of these fields is for the alignment of text in the slider & is hidden on output. I'm trying to get the value of this hidden field & use it to set a CSS class in the .tpl file, I've managed to do this but only in the .tpl file itself. If I understand it correctly it's best practise to get the value of this field in a preprocess function & expose it as a variable to the .tpl file, I'm unsure how to do this.

This is what I have written in the .tpl.php file, and it works, but from what I understand it's not best practise.

$key = key($items[0]["entity"]["field_collection_item"]);
$alignment = $items[0]["entity"]["field_collection_item"][$key]["field_image"]["#object"]->field_alignment["und"][0]["value"];

I'm using the Drupal module fences to modify output so the code above is in the field--fences-xl-slider.tpl.php file.

Answer 1

That could potentially break and it's pretty gnarly looking, so not the best, but I've been there!

Instead if you have the field_collection_item's ID you can do:

// I'd make a more meaningful name... like slider?
// If I understand your example, this should give you the entity Object for the field_collection_item
$entity = array_shift($items[0]["entity"]["field_collection_item"]);

$field_image_data = field_get_items('field_collection_item', $entity, 'field_image');
// I'm less sure here, it looks like the image is an entity and it has sub-fields?
// You'll probably have to dig through $image to see where the entity is kept, I'm guessing
$field_alignment_data = field_get_items('file?', $field_image_data[0]['#entity'], 'field_alignment');

// Now you should be at your field
// If safe_value exists, use that.
$alignment = $field_alignment_data[0]['value'];

This is annoying, but more legible. It's what happens when you have nested data objects, things just get kind of annoying.

The other option is you could make it a field that isn't hidden and use hide('field_alignment') in the tpl.php or template_preprocess_* function (guessing it'd be template_preprocess_entity?)