Right now, with have field_attach_preprocess() which needs to be moved to the entity system. Also, I guess it makes sense to have preprocessing logic that is tight the buildContent() of the render controller also in there, i.e. it should be moved from e.g. template_preprocess_node() into EntityViewBuilder::preprocessTemplate(). Then, we could just invoke that from there and deal with fields there as well.
Question is what should remain in e.g. template_preprocess_node() or not?
I'd say everything that relates to a special template should stay in template_preprocess_node(), everything that relates to something provided by the render controller, i.e. in buildContent should be moved there.
FAILED: [[SimpleTest]]: [PHP 5.4 MySQL] Unable to apply patch preprocess-2023571-39.patch. Unable to apply patch. See the log in the details link for more information. View
|#47||support_preprocessing-2023571-47.patch||10.69 KB||Manuel Garcia|
|#47||interdiff.txt||1.48 KB||Manuel Garcia|
|#51||before.png||17.5 KB||Manuel Garcia|
|#51||after.png||20.17 KB||Manuel Garcia|