How to make Experience Editor placeholders editable without placeholder settings?

Question

Normally, we need to define placeholders with allowed renderings in placeholder settings, to allow Experience Editor to support.

What is the way to configure placeholders editable in the Experience Editor if placeholder settings are not specified ?

Answer 1

from sitecore 6.5

setting name="WebEdit.PlaceholdersEditableWithoutSettings" value="false"

if needs to use dynamic placeholders or need to edit a placeholder without setting placeholder settings prior, then set this setting to "true".

Answer 2

There is a pipeline called getPlaceholderRenderings where you can define processors that can compute allowed renderings.