Problem/Motivation
A lot of expected and some unexpected (like the various Migrate getIDs) places use field types. Most of these places have a very poor / nonexisting explanation as to what a field type is.
Proposed resolution
FieldStorageDefinitionInterface has a better explanation "The field type, i.e. the id of a field type plugin. For example 'text'." Also, it points to FieldTypePluginManagerInterface which has @ingroup field_types . However, FieldTypePluginManagerInterface does not point to the FieldType annotation class which should be the nexus of this information much like for eg MigrateSource is.
Remaining tasks
Agree on a consistent and helpful wording for the explanation of field type. "The field type, i.e. the id of a field type plugin. For example 'text'." is an excellent start.
Add @see Drupal\Core\Field\Annotation\FieldType to FieldTypePluginManagerInterface
Add all the things to Drupal\Core\Field\Annotation\FieldType see MigrateSource an example.
Comments
Comment #1
dawehnerOne thing which would be really great to explain is the relationship between field types and field items/field item lists ...
Comment #2
dawehnerOne thing which would be really great to explain is the relationship between field types and field items/field item lists ...
Comment #3
ifrikIs this an issue for the documentation pages on d.o.?
In any case, it would be good to add/edit definitions like this in the glossary on d.o.
Comment #4
jhodgdonThis is a Drupal Core issue and is about programmer documentation. Maybe open a separate issue for the glossary?
Comment #5
ifrikThere is an issue for updating the online glossary, so any improved wording might be welcome there: #2430401: Updating the online glossary
Comment #16
catchRecategorising as a task and moving this to the field system, since it's pretty well self-contained in there.