DataObject::validate() is currently set to protected, but this means
you can't call validate() from outside the context of itself unless
you overload the method to use a public visibility and then call
parent::validate()
As it would turn out, most classes that overload this method already
set the visibility to public, so it would make sense the parent matches
that as well.
If we want DataObject->validate() to be used instead of
the form layer, we should allow for validation errors
to be passed through unchanged to the controller layer
so we can present them to the user. The context of
which class is written should be apparent from the stacktrace
of the exception.
Commit 964b3f2 fixed an issue where dbObject was returning casting helpers for
fields that were not actually DB objects, but had something in $casting config.
However, because dbObject was no longer calling DataObject->castingHelper, this
exposed a bug that the underlying function db($fieldName) was not returning
field specs for the base fields that are created by SS automatically on all
DataObjects (i.e. Created, LastEdited, etc).
This commit fixes the underlying issue that DataObject->db($fieldName) should
return the field specs for *all* DB fields like its documentation says it will,
including those base fields that are automatically created and do not appear in
$db.
Since ViewableData was returning a casting helper for Link, but DataObject was
only using $this->$fieldname to set values on that casting helper, you could
not use <% if Link %> (or <% if $Link %>) in your templates because Link is not
a field, and thus had no value to be set on the casting helper, causing
hasValue to think that there was no value. Since DataObject->dbObject says that
"it only matches fields and not methods", it seems safe to have it call db(..)
to get the field spec, and not call ViewableData->castingHelper at all.
This caused problems when duplicate() was used in the CMS UI
to duplicate a SiteTree object. Since every object of this type
has a ParentID relation, it copied this empty relation into
new "ghost page".
See https://github.com/silverstripe/silverstripe-cms/issues/689
When DataObject::update() is run with relation fields and the relationship
is new the relationship ID was not set on the DataObject. This patch fixes
this. Fixes issue 6195 in open.silverstripe.org.
