I am working on an edit form of a content type, which contains several related inline_entity_form, let's say ief1 and ief2. When I fill and submit ief1 and come to ief2, I need to access the input on ief1 to pre-populate some fields of ief2.
I have used
hook_inline_entity_form_entity_form_alter() and it return delta indexes of the submitted items of ief1.
How can I access the data I have entered to ief1, before the whole form submission?