From: Michael
Priestley [mailto:mpriestl@ca.ibm.com]
Sent: Friday, January 04, 2008
4:58 PM
To: Ogden, Jeff
Cc: dita@lists.oasis-open.org
Subject: Re: [dita] How much
flexibility do specializers have to make exceptions to behaviors that are
outlined in the DITA standard?
Hi Jeff,
I'm
uncomfortable with the first resolution below: "For the base
topic and map types both the “markup/syntax” and “processing
behaviors” described in the DITA specifications are required."
Specifically, I think the processing behaviors should remain explicitly
overrideable - maybe "required to be provided as default behaviors"?
I
believe there are cases where processing behaviors even for generic topics and
maps could legitimately be overridden by implementors. Otherwise we are
claiming that, for example, no one can generate links from maps except in the
way we specify, or change the way something is formatted... There were a few
examples I came up with before the holidays, I'll try to find them in the
archives.
In
the meantime, the architectural spec does have an explicit statement on
processing customization: http://docs.oasis-open.org/dita/v1.1/OS/archspec/customize.html
"When you just need a difference in output, you can use DITA customization
to override the default output without affecting portability or interchange,
and without involving specialization.
For
example, if your readers are mostly experienced users, you could concentrate on
creating many summary tables, and maximizing retrievability; or if you needed
to create a brand presence, you could customize the transforms to apply
appropriate fonts and indent style, and include some standard graphics and
copyright links.
Use customization when you need new output, with no
change to the underlying semantics (you aren’t saying anything new or
meaningful about the content, only its display)."
Michael
Priestley
Lead IBM DITA Architect
mpriestl@ca.ibm.com
http://dita.xml.org/blog/25
|
"Ogden, Jeff"
<jogden@ptc.com>
01/02/2008 03:30 PM
|
|
To
|
<dita@lists.oasis-open.org>
|
|
cc
|
|
|
Subject
|
Re: [dita] How much flexibility do
specializers have to make exceptions to behaviors that are outlined in the
DITA standard?
|
|
There are four long standing items toward the end of the DITA TC agenda:
1.
How much flexibility do specializers
have to make exceptions to behaviors that are outlined in the DITA standard?
(MUST, SHOULD, MAY discussion)
http://lists.oasis-open.org/archives/dita/200710/msg00025.html
2.
What does it mean when we say that
an implementation supports the DITA standard? Is the entire standard required
or are some parts optional?
3.
Is the scope of DITA 1.2 as it is
shaping up too large? Is the DITA specification becoming too complex?
4.
Is the approach outlined in the
proposed DITA 1.2 documentation TOC a good approach?
http://wiki.oasis-open.org/dita/Draft_1.2_TOC
We had
some good e-mail exchanges on the first item back in late October. The e-mail
discussion is included below. I don’t think that that discussion
lead to a consensus or any action items.
I’d
like to finish up the discussion on the first item, so we can start to work our
way through the next three items. I propose that anyone who wishes send any
last thoughts on this topic to the DITA TC e-mail list between now and next
Monday, that we have a brief discussion during next week’s DITA TC call
to see where we stand, and as part of that discussion see if we agree to the following
as a resolution of this issue:
1.
For the base topic and map types
both the “markup/syntax” and “processing behaviors”
described in the DITA specifications are required.
2.
For specializations the
“markup/syntax" described in the DITA specifications is required
unless explicitly stated otherwise.
3. For
specializations the "processing behaviors" described in the DITA
specifications are not required, but are strongly encouraged default behaviors
unless explicitly stated otherwise. Here “strongly encouraged”
means that there may be valid reasons in particular circumstances to implement
exceptions to the described default behavior, but the full implications of such
exceptions must be understood and carefully weighed before choosing to
implement behaviors that differ from the default behaviors described in the
DITA specifications.
4.
For user defined specializations
specific implementations will usually require possibly substantial additional
effort on the user’s part to implement exceptions to the default output
processing behaviors as described in the DITA specifications. Such
implementations are considered fully compliant with the DITA specifications.
5.
Using the general guidelines
outlined above the specification editors will review and update all of the DITA
specifications to ensure they are clear about what MUST, SHOULD, or MAY (see RFC 2119) be done
with respect to both the DITA document types that are officially part of the
standard (topic, map, concept, glossary, reference, task, bookmap,
learning/training specializations, and machine industry specializations) and
for user defined specializations that aren’t a formal part of the
standard.
6.
Members of the DITA TC are
encouraged to send suggestions to the specification editors about specific
items in the specifications that should have explicitly stated exceptions to
the general rules given above. Suggested exceptions can call for either
stricter or loser requirements. Any differences of opinion about
exceptions will be resolved as part of the review and approval process for the
DITA 1.2 specifications.
-Jeff
From: Ogden, Jeff [mailto:jogden@ptc.com]
Sent: Monday, October 15, 2007 5:39 PM
To: dita@lists.oasis-open.org
Subject: [dita] How much flexibility do specializers have to make
exceptions to behaviors that are outlined in the DITA standard?
We’ve
had some e-mail discussions about “How much flexibility specializers have
to make exceptions to behaviors that are outlined in the DITA standard”.
But those discussions have been fairly quiet for 10 days or so. We had
some good discussion of this during the last DITA TC meeting. During that
discussion we agreed to move the discussion back to the DITA TC e-mail list.
So
this note is my attempt to get the e-mail discussion restarted.
I
don’t think we want to talk about this issue during tomorrow’s DITA
TC call, but if we can get some good discussion going on the e-mail list we may
be ready to talk about it during next week’s call.
I
think Gershon’s draft meeting minutes provide a pretty good summary of
the discussion, so far. From the draft 9 October 2007 meeting minutes:
> 4) How much
flexibility do specializers have to make exceptions to
> behaviors that
are outlined in the DITA standard?
>
>
JO: We had good discussions. MP has a more liberal approach,
>
whereas I feel we should not permit as much flexibility.
>
>
MP: I'm drawing the line between syntax and behavior. Syntax
>
must be preserved. Everything beyond there is pretty contextual.
>
>
JE: There are edge cases where we've had to deviate from the
>
standard in order to achieve the specialization we needed.
>
Though these are minor deviations that could be easily
>
transformed back into standard DITA.
>
>
Discussion...
>
>
MP: If someone wants to override the stated default behavior
>
(for some good reason), I don't think we should call that going
>
against the DITA spec.
>
>
Discussion...
>
>
Don requested we move this discussion to the email list.
>
>
Yet further discussion...
>
>
Don asked us to take items 3 and 4 off into 2 discussions next
>
week. In the meantime, continue discussions on-list.
Much
of the discussion so far has been between Michael and me. I’d like
to see if we can get some others to express their views on this issue. If
most people don’t care or if most people agree with Michael that
specializers can do pretty much anything they want, we may not need a lot more
discussion. If this position makes some people uneasy, then we need to
find that out and we will need to continue the discussion to figure out how and
where to draw some lines.
I
believe that there is agreement that specializers have a lot of control and can
change many things related to output processing behaviors of their
specializations. I think there is also agreement that we need to review the
DITA specifications to make sure they are clear about what MUST, SHOULD, or MAY
be done with respect to both the basic DITA document types that are officially
part of the standard (topic, map, concept, glossary, reference, task, and
bookmap) and for user defined specializations that aren’t a formal part
of the standard. I am a little less sure, but I think there is agreement that
we want to add some sort of conformance statement to the DITA specifications.
The
question that is up for discussion is, are specializers free to do anything
they want or are there some things that the DITA Standard makes out of bounds
even for user defined specializations that aren’t part of the official
DITA standard?
From
my point of view, I’d like to see some limits on what specializers can do
in terms of referencing behaviors (what legal DITA URI’s can look like
and what they mean), and when there are interactions such as property cascading
behavior between one document and another (from a map to a topic or from a map
to a map to a topic). I want to increase the likelihood that DITA users
can share their documents, including specialized documents, with others or move
the documents into new processing environments and still get good results.
I want to reduce the amount of reimplementation users have to do when
they share their documents or move into new processing environments.
Paul
Grosso described this in terms of the distinction that is made in XSLT between
transformations and styling. Styling would be very open and specializers could
do pretty much whatever they want. Transformations (explicit or implied)
would be more tightly defined by the DITA Standard and specializers would have
less flexibility (but still some flexibility). Paul, feel free to restate
this if what I wrote here isn’t quite right.
I’ll
shut up now. Please let us know what you think.
-Jeff
From: Deborah_Pickett@moldflow.com
[mailto:Deborah_Pickett@moldflow.com]
Sent: Tuesday, October 16, 2007 11:56 PM
To: Ogden, Jeff
Cc: dita@lists.oasis-open.org
Subject: Re: [dita] How much flexibility do specializers have to
make exceptions to behaviors that are outlined in the DITA standard?
"Ogden, Jeff" <jogden@ptc.com> wrote on 16/10/2007 07:39:06 AM:
> The question that is up for discussion is, are specializers free to
> do anything they want or are there some things that the DITA
> Standard makes out of bounds even for user defined specializations
> that aren’t part of the official DITA standard?
I prefer for the standard to make no promises, and let specializers take as
much rope as they need.
> From my point of view, I’d like to see some limits on what
> specializers can do in terms of referencing behaviors (what legal
> DITA URI’s can look like and what they mean),
Interesting that you bring up URIs. Inevitably some specialization is
going to come along that wants to link to somewhere in a way that isn't covered
by existing hrefs. We don't have a standard way of making new href-like
attributes, and to cater to those specializations we need to. Or do we:
is this what data/@href is for?
And because that made me think of xlink, it reminds me that something we have
also not discussed for an awfully long time is namespaces. Are DITA
specializers allowed to add namespaced attributes?
> I want to increase the likelihood that DITA users can
> share their documents, including specialized documents, with others
> or move the documents into new processing environments and still get
> good results. I want to reduce the amount of reimplementation users
> have to do when they share their documents or move into new
> processing environments.
This is a little tangential, but depending on how we approach a solution, it
might not be.
I suppose that a common scenario is that I have a document that contains a
specialization, but for $transform I don't have any processing to handle that
specialization, so I get fallback behaviour.
Sometimes fallback behaviour is fine. The UI domain, for instance, is
hardly groundbreaking, and falling back to <ph> is not going to hurt.
Sometimes fallback behaviour is ugly. The Utilities domain's
<imagemap> element doesn't really work if rendered as a plain
<fig>: you end up seeing the coordinates as plain text. (I suppose
the real culprit here is the <shape> element rather than its ancestor
imagemap, and that if it were omitted you'd get something at least
presentable.)
How can the processor know when fallback behaviour is acceptable? Is
there some way for a <shape> to say to the processing for its base
topic/keyword, "skip me" (or "die")? (Obviously the
answer today is "no, there isn't", so really my question is "is
this something we want?".)
--
Deborah Pickett
Information Architect, Moldflow Corporation, Melbourne
Deborah_Pickett@moldflow.com
From: Michael Priestley
[mailto:mpriestl@ca.ibm.com]
Sent: Thursday, October 25, 2007 3:21 PM
To: Eliot Kimber
Cc: dita
Subject: Re: [dita] How much flexibility do specializers have to
make exceptions to behaviors that are outlined in the DITA standard?
Hi Eliot,
Re:
> All addressing of DITA-governed content by DITA-governed content. That is,
> you cannot, within a specialization, change the rules for resolving hrefs
> (or any other DITA-defined addressing mechanism)) to DITA-based content.
Couldn't the implementer choose to create hoverhelp for a link to APItopics by
summarizing the syntax, rather than always pulling the shortdesc? Agreed the
syntax should be consistent, but why limit what we do with that syntax?
> Conref. You cannot change the constraints or effective result that conref
produces.
Couldn't an implementer decide that they want to limit reuse in their
organization to content coming from specific directories? For example, check
the conref path to ensure that it starts with "/reuse/"?
It seems to me that one of the advantages of having conref as an explicit
process rather than something that happens as part of parsing (as with entities
or XIncludes) is that you can, as an implementer, choose to enhance or restrict
the processing according to your local requirements.
Michael Priestley
Lead IBM DITA Architect
mpriestl@ca.ibm.com
http://dita.xml.org/blog/25
-----Original
Message-----
From:
Eliot Kimber [mailto:ekimber@reallysi.com]
Sent:
Thursday, October 25, 2007 3:10 PM
To:
dita
Subject:
Re: [dita] How much flexibility do specializers have to make
exceptions
to behaviors that are outlined in the DITA standard?
On
10/15/07 4:39 PM, "Ogden, Jeff" <jogden@ptc.com wrote:
> The question that is up for
discussion is, are specializers free to do
> anything they want or are there some things that
the DITA Standard makes
> out of bounds even for user defined
specializations that aren't part of
> the official DITA standard?
> From my point of view, I'd like to see some limits
on what specializers
> can do in terms of referencing behaviors (what
legal DITA URI's can look
> like and what they mean), and when there are
interactions such as
> property cascading behavior between one document
and another (from a map
> to a topic or from a map to a map to a topic).
I want to increase the
> likelihood that DITA users can share their
documents, including
> specialized documents, with others or move the
documents into new
> processing environments and still get good
results. I want to reduce
> the amount of reimplementation users have to do
when they share their
> documents or move into new processing
environments.
The
DITA specification defines a number of core processing semantics that
constitute
the core processing infrastructure that makes DITA both work
functionally
(that is, when implemented, those features produce the result
that
you presumably want because you're using DITA) and allows documents
and
document processing to be reasonably interchangeable.
I
think that this infrastructure includes the following:
-
All addressing of DITA-governed content by DITA-governed content. That
is,
you cannot, within a specialization, change the rules for resolving hrefs
(or
any other DITA-defined addressing mechanism)) to DITA-based content.
-
Conref. You cannot change the constraints or effective result that conref
produces.
Where
things start to get a little cloudier, and where I think this
discussion
started, is in the area of the implications for topic references
and
in particular how do topic references affect the effective properties
of
the topics they reference?
The
issue here is that while this area can be viewed as concrete in the
way
that addressing and conref are, it can also be seen as a matter of
presentation
style. For example, for some specializations of metadata used
within
topicref I want their values to propagate and replace values on
referenced
topics and for other values I do not. A blanket DITA-defined rule
of
"metadata always propagates" or "metadata never propagates"
would be
wrong
some of the time so we can't define it. That leads to Paul's original
question
of how can specializations express their intent in a case like
this
that allows a tool like Arbortext Editor to do the expected thing
automatically?
Clearly in this specific case there's a need for some sort
of
schema-level way to indicate the processing intent.
Simple
enough to design for this case, but how many cases are there?
Probably
lots. That suggests you need a more general mechanism for this
sort
of thing. That will be, necessarily, complex. Easier to just punt and say
"DITA
has no opinion". But that doesn't help Paul. Seems like, for the
moment,
there's no easy answer to this question.
At
a minimum DITA has to define clear default behaviors for those areas
where
processors can legitimately do different things.
I
guess I would need to see some specific cases where a specialization
wants
to deviate from either the defined or suggested behavior to evaluate
whether
or not the deviation is processing or style, there's a way to usefully
parameterize
the behavior choices or whether the requirement can be
satisfied
in a different way. Or where, as above, DITA either says nothing
or
isn't clear and there are multiple useful ways that a processor could
behave.
It's
also worth saying that while DITA should "just work" that's always in
terms
of the default behavior, whatever it is, as defined by the DITA spec.
Specializations
that want something other than the default are on their
own
and there should be no expectation on anyone's part that
specialization-specific
stuff will magically happen without some
implementation
effort.
In
that respect, DITA-based applications are no different from any other
purpose-built
XML application in that you may have to do a bit of local
customization
of your generic tools to get what you want. However, with DITA
it
should always be less (or no greater than) it would have otherwise been
because
DITA gives you so much out of the box.
For
example, for demonstration purposes I've defined a specialization of
reference
for capturing animal field guide entries, including
specializations
of <data for capturing the Linnaean classification of the
animals
described. No DITA-aware processor is going to give me any special
support
for authoring these classifications but I'd probably want to build
a
little classification editor for these values since they need to be
validated
and could be gathered from external data sources and whatnot. I
would
not fault any DITA-supporting editor for not providing that but I
would
expect a way to add it without too much difficulty.
Cheers,
Eliot
--
W.
Eliot Kimber
Senior
Solutions Architect
Really
Strategies, Inc.
From: Michael Priestley
[mailto:mpriestl@ca.ibm.com]
Sent: Thursday, October 25, 2007 3:41 PM
To: Michael Priestley
Cc: dita; Eliot Kimber
Subject: Re: [dita] How much flexibility do specializers have to
make exceptions to behaviors that are outlined in the DITA standard?
Clarification:
in the href overriding example, a processor might choose to create a preview by
summarizing specialized elements in a target's <refsyn> or equivalent,
rather than using the <shortdesc>. This wouldn't affect the syntax of the
href, but does change the expected processing from the default.
I realized in my wording below I used the word syntax twice to mean two
different things :-)
Main point remains the same: I think everything in "expected
behavior" is expected default behavior; everything in "expected
markup/syntax" is required unless otherwise stated. The syntax for href
and conref should be standard; the expected behavior should be default.
Michael Priestley
Lead IBM DITA Architect
mpriestl@ca.ibm.com
http://dita.xml.org/blog/25
>
-----Original Message-----
From:
Eliot Kimber [mailto:ekimber@reallysi.com]
Sent:
Thursday, October 25, 2007 4:04 PM
To:
Michael Priestley
Cc:
dita
Subject:
Re: [dita] How much flexibility do specializers have to make
exceptions
to behaviors that are outlined in the DITA standard?
On
10/25/07 2:41 PM, "Michael Priestley" <mpriestl@ca.ibm.com>
wrote:
> Clarification:
>
> in the href overriding example, a processor might choose
to create a
> preview by summarizing specialized elements in a
target's <refsyn> or
> equivalent, rather than using the <shortdesc>.
This wouldn't affect the
> syntax of the href, but does change the expected
processing from the
> default.
What
you've described is rendition, not address resolution.
That
is, when I say "addressing" I mean "the object that is addressed
by the
href
value" which is different with what you do with that thing once you have
it.
That
is, how or if you produce tooltips in some rendition is entirely a
matter
of style. What those tooltips apply to (or at least what the initial
source
of their ultimate value is) is a function of invariant address processing.
That
is, you can choose to produce or not produce tooltips, you can't change
what
"mytopic.dita#topicid/elementid" means from an address resolution
standpoint.
[Note
that this is one problem with DITA not using standard addressing
mechanisms:
it provides no built in mechanism for choice in how you do
addressing
at the fragment identifier level, which means you either have
non-DITA
stuff or you use URIs that have to be interpreted by a specific URI
resolver.
This is a fundamental problem with DITA 1.x that must be corrected
in
DITA 2.]
> Main point remains the same: I think everything in
"expected behavior" is
> expected default behavior; everything in "expected
markup/syntax" is
> required unless otherwise stated. The syntax for href
and conref should be
> default.
But
the point is that that there are some things in DITA that are not
"expected
behavior" but "required behavior", which includes, I assert, all
addressing
and conref.
Cheers,
E.
--
W.
Eliot Kimber
Senior
Solutions Architect
Really
Strategies, Inc.
From: Ogden, Jeff [mailto:jogden@ptc.com]
Sent: Thursday, October 25, 2007 6:18 PM
To: Michael Priestley; Eliot Kimber
Cc: dita
Subject: RE: [dita] How much flexibility do specializers have to
make exceptions to behaviors that are outlined in the DITA standard?
Eliot,
thanks for your comments and for getting this conversation started again.
In
response to Michael’s comment/question:
> Couldn't an implementer decide that they want to limit
reuse in their organization
> to content coming from specific directories? For
example, check the conref path
> to ensure that it starts with "/reuse/"?
I
don’t see a problem with this as long as the implementer is being more
restrictive than what is required by the standard. The standard says that
conref values are URIs that reference DITA content with a number of checks to
make sure they content being referenced is legal or is likely to be legal in
the new context. Limiting the references to a particular path isn’t
violating that. The conref values that start with /reuse/ will always be valid
URI and with a bit of luck the thing being referenced will be DITA content that
is legal in the current content. An implementation will not have to do anything
special to make the required checks. You can’t expect other
implementations to impose the same limitations automatically, but that is OK.
-Jeff
From: Michael Priestley
[mailto:mpriestl@ca.ibm.com]
Sent: Thursday, October 25, 2007 6:22 PM
To: Eliot Kimber
Cc: dita
Subject: Re: [dita] How much flexibility do specializers have to
make exceptions to behaviors that are outlined in the DITA standard?
I guess I was having trouble separating out "addressing" as a
behavior from the various actual processes that use addressing. I see your
point.
I was thinking of addressing as "what the syntax means" - for example
topicid/elementid - we wouldn't want that to be overridden by processing, it's
not even clear to me what overriding that would mean. But I buy that processing
for addresses should not ignore or misinterpret the actual information in the
address. That said, all the processes that do something with the info at that
address should be overrideable - like shortdesc pulling, link creation, etc.
etc.
For conref, which goes beyond the address, where do we draw the line? Is there
a problem with my example? Or is it another case where the syntax's meaning is
preserved, so even if the exact behavior as described in the spec doesn't apply
it still is preserving the important part of the process, ie the meaning of the
address?
As another conref example: we say you can generalize on the fly where
necessary/appropriate - I can imagine someone overriding the generalization to,
for example, generate titles for specialized sections that are being
generalized during conref. Is that ok? Are there other conref overrides that
wouldn't be ok, for example overriding the process to allow conref across
specializations without generalization at all?
Michael Priestley
Lead IBM DITA Architect
mpriestl@ca.ibm.com
http://dita.xml.org/blog/25
The
End