fo:margin-right (and other margin attributes)

[Patrick Durusau <patrick@durusau.net>]

Greetings!

We variously define fo:margin-right in the current draft, which I am in 
the process of reducing to one definition (hopefully) but we also say 
(for example):

> The margins attributes |fo:margin|, |fo:margin-top|, 
> |fo:margin-bottom|, |fo:margin-left| and |fo:margin-right| specify the 
> size of the page margins. Percentage values are not supported.
>
Note the comment about percentage values.

Well, this is an illustration of why I dislike schema fragments.

If you look in version 6, 16.2.5 you will find:

<define name="style-page-layout-properties-attlist" combine="interleave">
    <ref name="common-horizontal-margin-attlist"/>
    <ref name="common-vertical-margin-attlist"/>
    <ref name="common-margin-attlist"/>
</define>

Not very informative is it?

If I were going to add something here that was informative it would be a 
graphic rendering of the element in question with its attributes listed 
(with their datatypes).

You have to realize that schema fragments reflect our *authoring* 
practices for schemas and are not really a good means of communicating 
about the structure or content of schemas.

So, if you do run "common-horizontal-margin-attlist" to resolution you 
will find:

<define name="common-horizontal-margin-attlist">
    <optional>
        <attribute name="fo:margin-left">
            <choice>
                <ref name="length"/>
                <ref name="percent"/>
            </choice>
        </attribute>
    </optional>
    <optional>
        <attribute name="fo:margin-right">
            <choice>
                <ref name="length"/>
                <ref name="percent"/>
            </choice>
        </attribute>
    </optional>
</define>

Opps! Percent is in fact there, contrary to the prose in any number of 
places for borders.

BTW, where we do differ from xsl-fo is that we don't support "auto" as a 
value for this attribute.

What I am contemplating is creating a table that has numbered entries, 
for ease of reference, that has a canonical reference to the definition 
of any attribute in a foreign schema and then a column that describes 
any departure from the definition in the other schema. No comment, no 
deviation. Actually we should be trying to use foreign attributes "as 
is" in order to get the maximum benefit from the use of other schemas.

That is to say if we use a foreign attribute, we should not comment on 
it other than to make a reference to its definition elsewhere.

Hope everyone is having a great day!

Patrick

-- 
Patrick Durusau
patrick@durusau.net
Chair, V1 - US TAG to JTC 1/SC 34
Convener, JTC 1/SC 34/WG 3 (Topic Maps)
Editor, OpenDocument Format TC (OASIS), Project Editor ISO/IEC 26300
Co-Editor, ISO/IEC 13250-1, 13250-5 (Topic Maps)