namespaces in subtree filtering
Martin Bjorklund <mbj@tail-f.com> Wed, 21 March 2007 10:03 UTC
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Date: Wed, 21 Mar 2007 10:54:01 +0100
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To: netconf@ops.ietf.org
Subject: namespaces in subtree filtering
From: Martin Bjorklund <mbj@tail-f.com>
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Andy noted at the meeting that subtree filtering can't be used to retreive elements from mulitple namespaces. The text from rfc4741, section 6.2.1 says: If namespaces are used, then the filter output will only include elements from the specified namespace. A namespace is considered to match (for filter purposes) if the content of the 'xmlns' attributes are the same in the filter and the underlying data model. This is somewhat difficult to interpret. What exactly does "the 'xmlns' attributes" mean? Note the plural. Suppose we have this in the database: <if:interfaces xmlns:if="http://example.com/interface"> <if:interface> <if:ifIndex>1</if:ifIndex> <if:ifType>ds0</if:ifType> <ds0:circuitIdentifier xmlns:ds0="http://example.com/ds0">foo</ds0:circuitIdentifier> </if:interface> </if:interfaces> Accordning to the example in 6.2.1, the following filter: <get> <filter> <if:interfaces xmlns:if="http://example.com/interface"/> </filter> </get> would return <if:interfaces xmlns:if="http://example.com/interface"> <if:interface> <if:ifIndex>1</if:ifIndex> <if:ifType>ds0</if:ifType> </if:interface> </if:interfaces> Suppose instead the filter is <get xmlns:if="http://example.com/interface"> <filter> <if:interfaces/> </filter> </get> Note that no xmlns attributes are present in the filter itself. Would we get the ds0 elements as well? What about this filter: <get> <filter> <if:interfaces xmlns:if="http://example.com/interface" xmlns:ds0="http://example.com/ds0"/> </filter> </get> Here we have two xmlns attributes. Would we get the ds0 elements in this case? IMO, it's unfortunate that the xmlns attribute is overloaded with this filter semantics. I don't really see the value in this namespace selection mechanism at all. Are there any use cases where it makes sense? /martin -- to unsubscribe send a message to netconf-request@ops.ietf.org with the word 'unsubscribe' in a single line as the message text body. archive: <http://ops.ietf.org/lists/netconf/>
- namespaces in subtree filtering Martin Bjorklund
- Re: namespaces in subtree filtering Phil Shafer
- Re: namespaces in subtree filtering Martin Bjorklund
- Re: namespaces in subtree filtering Phil Shafer
- Re: namespaces in subtree filtering Andy Bierman
- Re: namespaces in subtree filtering Phil Shafer
- Re: namespaces in subtree filtering Andy Bierman