Kris,
At the bottom of the same topic under “Effective Key Definitions,” there’s this (emphasis added):
<quote>
Effective key definitions
For a given key there is at most one effective definition within a key space. A key definition is the effective definition for a given key if it is the first, in document order, within the map document that contains it, and is the first in the map tree in breadth-first order. It is not an error for the same key name to be defined more than once within a map or map tree, and duplicate key definitions should be ignored without warning.
</quote>
I take the spec to say that sub-maps are processed in document order, but key definitions within the same map are determined in breadth-first order. So, to use your example map, if B and A.1 both defined the same key name, then B would be the effective definition. But if B and A.1 were both references to sub-maps, A.1 would be processed before B.
Where things get fuzzy for me is when A.1 is a reference to a sub-map, B is a key definition, and the sub-map referred to by A.1 contains a key definition for the same key defined on B. In that case, I think B wins (and that’s how we’ve implemented it), but I’m only about 90% sure.
Chris
From: Kristen Eberlein [mailto:keberlein@sdl.com]
Sent: Friday, January 21, 2011 11:16 AM
To: dita@lists.oasis-open.org
Cc: Mark DeVries
Subject: [dita] Question about order in which keys are resolved
Several SDL developers have had questions pertaining to the order in which keys are resolved. I’ve been asked whether keys are resolved in document- or breadth-order, according to the following example:
map
topicref id="A"
topicref id="A.1"
topicref id="A.1.1" href=""first-in-document-order.dita"
topicref id = "B" href=""first-in-breadth-first-order.dita"
Document order = A, A.1, A.1.1, B
Breadth-first order = A, B, A.1, A.1.1
My answer is that keys are resolved in document order, per the following definition of “Key spaces” in the spec:
Key spaces
A root map and its directly addressed, local scope descendant maps establish a unique key space within which each unique key name has exactly one binding to a set of resources.
For the purposes of determining the effective key definitions for the key space represented by a given root map, a map tree is determined by considering only directly addressed, local scope maps descending from the root map. The order of subordinate maps is determined by the document order of the topicrefs that point to them. Indirect references to maps with key references are necessarily ignored until after the key space is determined.
Maps addressed by <navref> do not contribute to the key space of a map tree. Maps referenced by <navref> are equivalent to maps referenced with a scope of "peer" or "external" and therefore need not be present or available at the time the referencing map is processed for purposes of key space construction.
Can y’all confirm that I am giving accurate guidance?
Best regards,
Kris
Kristen James Eberlein l DITA Architect and Technical Specialist l SDL Structured Content Technologies Division l (t) + 1 (919) 682-2290 l keberlein@sdl.com
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