Add the Model to the form and override IModel#getObject() return updated
new "Post" object. I read on this mailing list not to set Models.
An example with a LoadableDetachableModel.
Form blogPostForm = new Form(id, new
CompoundPropertyModel(new LoadableDetachableModel()
I'm saving a 'Post', like a blog post, and JPA's merge function doesn't
update the object in place but rather, returns an object reflecting the new
database fields (like "id" if it were set).
In my application, I'd like to manage insert / update by setting this new
'Post' as the model for my form.
