DOCBOOK: Allow StartsWith/ContinuationOf on OrderedList?

[Norman Walsh <ndw at nwalsh dot com>]

Having just described why the answer to this question

  Given the following structure

  <orderedlist id="list1">
    <listitem>...</listitem>
    <listitem>...</listitem>
    <listitem>...</listitem>
    <listitem>...</listitem>
    <listitem>
      <orderedlist id="list2">
        <listitem>...</listitem>
        <listitem>...</listitem>
      </orderedlist>
    </listitem>
  </orderedlist>

  <orderedlist id="list3" continuation="continues">
    <listitem id="citem">...</listitem>
    <listitem>...</listitem>
  </orderedlist>

  What is the proper value for the numeration of listitem "citem"?

Cannot be "5", I feel obligated to offer the document author
some way to assert that it is "5", since that is a reasonable
thing for the author to want to do.

I can think of two options:

1. Add a "StartsWith" attribute to OrderedList so that the author
   can set the starting number explicitly.

   Pros: simple; solves the problem; offers additional flexibility,
         can be used to start list numbering arbitrarily (and
         independent of) continuation.

   Cons: it's fragile, if the author does this to get the value "5"
         in the preceding example, and then adds a new listitem to
         "list1", "list3" will still begin at 5.

2. Add a "ContinuationOf" attribute which is an IDREF to the list
   which the author would like to continue.

   Pros: robust; solves the problem
   Cons: slightly more complex; less flexible, you can't just number
         a list starting at 37 because you like the number 37.

I prefer 2. I suppose we could add both 1 and 2, but we've
generally tried to resist solving problems that people didn't
claim to have (yet).

If we elect to go with option 2, then we should probably
deprecate and then remove "Continuation".

                                        Cheers,
                                          norm

-- 
Norman Walsh <ndw@nwalsh.com>      | Everything in the univese goes by
http://www.oasis-open.org/docbook/ | indirection. There are no straight
Member, DocBook Editorial Board    | lines.--Emerson