Field collection
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Provides a field collection field, to which any number of fields can be attached.
Each field collection item is internally represented as an entity, which is
referenced via the field collection field in the host entity. While
conceptually field collections are treated as part of the host entity, each
field collection item may also be viewed and edited separately.
Usage
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* Add a field collection field to any entity, e.g. to a node. For that use the
the usual "Manage fields" interface provided by the "field ui" module of
Drupal, e.g. "Admin -> Structure-> Content types -> Article -> Manage fields".
* Then go to "Admin -> Structure-> Field collection" to define some fields for
the created field collection.
* By the default, the field collection is not shown during editing of the host
entity. However, some links for adding, editing or deleting field collection
items is shown when the host entity is viewed.
* Widgets for embedding the form for creating field collections in the
host-entity can be provided by any module. In future the field collection
module might provide such widgets itself too.
Using field collection with entity translation
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* Field collection items must be selected as a translatable entity type at
Admin -> Config -> Regional -> Entity Translation.
* The common use case is to leave the field collection field untranslatable
and set the necessary fields inside it to translatable. There is currently
a known issue where a host can not be translated unless it has at least
one other field that is translatable, even if some fields inside one of
its field collections are translatable.
* The alternate use case is to make the field collection field in the host
translatable. If this is done it does not matter whether the inner fields
are set to translatable or not, they will all be translatable as every
language for the host will have a completely separate copy of the field
collection item(s).
