RequestHandler#handleAction now exists. It takes the request, and
the action to call on itself. All calls from handleRequest to call an action
will go through this method
Controller#handleAction has had it's signature changed to
match new RequestHandler#handleAction
RequestHandler#findAction has been added, which extracts the
"match URL to rules to find action" portion of RequestHandler#handleRequest
into a separate, overrideable function
GridField#handleAction has beeen renamed to handleAlterAction and
CMSBatchActionHandler#handleAction has been renamed to handleBatchAction to
avoid name clash with new RequestHandler#handleAction
Reason for change: The exact behaviour of request handling depended heavily
on whether you inherited from RequestHandler or Controller, and whether the
rule extracted it's action directly (like "foo/$ID" => 'foo') or dynamically
(like "$Action/$ID" => "handleAction"). This cleans up behaviour so
all calls follow the same path through handleRequest and handleAction, and
the additional behaviour that Controller adds is clear.
We shouldn't pass it to the child fields since it ends
up showing the description three times in the default
"inline" mode. If the description is required as a hover/focus effect,
it can be set individually on the fields.
Sometimes has-one UploadFields can get confused about whether or not there is an existing file that needs deleting. This setting lets you make a more robust has-one UploadField, where any existing file will be replaced. It more closely mimics simple single-file upload fields.
This is the companion setting to canUpload, letting you control whether existing files from the asset store can be referenced. It's particularly useful when using UploadField on the front-end.
Although editing meta-data or deleting permanently would require File editing/deleting permissions, merely linking to a record does not. This change is important for allowing front-end use of UploadField; or, more importantly, use of UploadFile by people without CMS rights.
The new config setter restores the 2.4 behaviour of including <input type="hidden"> with a field. Although as a default, this option has security flaws; it is useful in a few circumstances and, if nothing else, is handy to make upgrading sites easier.
This hook is useful so that you can add additional fields / actions in a gridfield form that are not available in other settings (e.g. additional actions: previous / next / save and publish / unpublish / etc
