On 2/17/11 10:28 AM, Stefan Seelmann wrote:
On Thu, Feb 17, 2011 at 9:37 AM, Emmanuel Lécharny<[email protected]> wrote:
On 2/17/11 12:43 AM, Alex Karasulu wrote:
On Thu, Feb 17, 2011 at 1:20 AM, Emmanuel Lécharny<[email protected]>
wrote:
On 2/17/11 12:03 AM, Alex Karasulu wrote:
On Thu, Feb 17, 2011 at 12:55 AM, Emmanuel Lécharny
<[email protected]> wrote:
On 2/16/11 9:02 PM, Alex Karasulu wrote:
On Wed, Feb 16, 2011 at 4:50 PM, Emmanuel
Lecharny<[email protected]>
wrote:
Hi,
we have had some convo about the Dn methods last night. Here are some
of
the things we discussed and came with :
o the getPrefix(N)/getSuffix(N) are cumbersome, and not easy to
manipulate. The main issue is that they depend on the RDN order,
which
is
the opposite as what people are used to manipulate. Everytime you
have
to
get a prefix from a Dn, you always wonder what the position should
be,
and
if it's 0 based or 1 based...
We propose to replace those methods by getParent(Dn) and
getDescendant(Dn). Let me give you an example :
// A DN
Dn dn = new Dn( "cn=test,ou=server,ou=directory,dc=apache,dc=org" );
// Get the right part (equivalent to getprefix( 2 ) )
Dn parent = dn.getParent( "cn=test,ou=server,ou=directory" ); //
returns
"dc=apache,dc=org"
// Get the left part (equivalent to getSuffix( 3 ))
Dn descendant = dn.getDescendant( "ou=directory,dc=apache,dc=org" );
//
returns "cn=test,ou=server"
o The Add method is a bit annoying to remove, because first, the JNDI
Name interface has such a method, and people are used to it, second
removing
it means we have to add some more constructors line Dn( Dn, Rdn... ).
I
agree that someone doing something like :
Dn dn = new Dn( "dc=apache,dc=org" );
dn.add( "ou=directory" );
will expect that the dn is now "ou=directory,dc=apache,dc=org", when
it's
unchanged.
This is really troublesome... What about rename it concatenate() ?
Thoughts ?
Sounds good. But how about this:
// not showing full Rdn but an index value representing the actual
rdns in the dn for pos clarity
Dn dn = new Dn( “9, 8, 7, 6, 5, 4, 3, 2, 1, 0” );
dn.getAncestorDn( “9, 8, 7, 6” );
=> “5, 4, 3, 2, 1, 0”
That's ok, but why not getParent() ?
Because the result is not necessarily the parent of 'dn'. It may be if
it's immediately superior. You're mixing together the meanings I
think.
Sorry, I don't get it. You have a DN, and you want the parent of it's
left
part, how possible the result couldn't be the parent ? If the parameter
is
not the left part, then you get an exception, but that's in the contract.
Did I missed something ?
The dn is “9, 8, 7, 6, 5, 4, 3, 2, 1, 0” you're getting one of it's
ancestors not it's parent.
The parent would be “8, 7, 6, 5, 4, 3, 2, 1, 0”, the ancestor in the
example is “5, 4, 3, 2, 1, 0”.
You see what I mean?
Alex
Bottom line, it does not really matter... What is important is that we agree
on a name that express what the operation does.
So, considering that a DN can be expressed either as [RDN][DNp] or
[DNd][DNa] with DNp = parent, DNa = ancestor, DNd = descendant (DNp and DNa
are equivalent, it's just that a DNa may have a DNd, when a DNp can only ave
a RDN) :
* Dn.getParent() -> returns the DNp in [RDN][DNp]
* Dn.getAncestor( DNd ) -> returns the DNa in [DNd][DNa]
* Dn.getDescendant( DNa ) -> returns the DNd in [DNd][DNa]
+1, please also add that definition to the Javadoc, this is a really
nice, short, and clean description what the methods do.
Yes, sure, will do.
Is that ok ? Should we use something more clear, like
getAncestorOf/getDescendantOf ? Or use getAscendant/getDescendant ?
I would prefer getAncestorOf/getDescendantOf.
One concern: What is the use case of the getAncestorOf/getDescendantOf
from the user's point of view? In the server and in studio such
methods are useful (e.g. calculating the local name for ACI handling).
But does the end user of the API really need those methods? I mean we
should avoid to put methods into the Dn class that is only/mostly used
in server and studio. Maybe a DnUtils class with static methods for
advanced DN processing would help?
Good point. I can see some case where you need to split the DN in two
parts, for instance if you access two servers looking for an entry for
which you have the name. For instance, if you have two ldap server, one
in US and one in FR, you may have an entry present as "cn=John Doe,
dc=acme, c=us" or "cn=John Doe, dc=acme, c=fr", you may want to get the
ancestor to know in which server the entry is stored into.
Know, we can also provide some helper class to do that, but I'm afraid
users will 'torture' the DN instead of using the DnUtils class, simply
because hey won't know that such a class exists.
Any opinion about the add() vs concatenate() methods ?
--
Regards,
Cordialement,
Emmanuel Lécharny
www.iktek.com
