How can I get the id of a file that appears in a channel entry?

Question

I have a channel called Knowledge Item, and one of its fields is a file. I want to embed the ID of the file in a hidden field in my template. I was doing this and thought it was working;

<input type="hidden" id="knowledge_item_entry_id" value="{entry_id}" />

until I realised that {entry_id} refers to the entry id of the parent channel entry, not the file itself.

Is there a syntax to access properties like these from within a template please?

Answer 1

You would just use the file field's tag pair and the file_id varaiable like this:

{file_field_name}{file_id}{/file_field_name}