symfony sfDoctrineRoute model question

I couldn't understand completely how does the sfDoctrineRoute class works

for example, i have the following route:

Comment:
  class: sfDoctrineRouteCollection
  options:
    prefix_path: :username/comment
    module: comment
    model: Comment

now, in executeNew() method of commentActions class, this code:

$this->getRoute()->getObject()

will return the first Comment object in my database. of course i can manually create a new Comment() object, but then what's the benefit of usin开发者_如何学Gog the sfDoctrineRoute class instead of sfRoute?

In the case of executeNew, there is little/no benefit to using a doctrine route.

Consider instead the executeEdit method (update, delete and show are the same too).

A url could be like:

/comment/5/edit

(or in your case, /myusername/comment/5/edit)

$this->getRoute()->getObject() will then return comment 5 from the database - saving you the trouble of loading it (only a line or 2 of code, but still). And, a neat feature, if there is no comment 5 in the database, it automatically handles this and causes a 404 error - so you don't need to worry about that either.