On Wed, 16 Sep 1998 Massimo Castellacci asked:

> Could you tell me, in EAD DTD 1.0, what are the tags and the related
> attributes to obtain hypertextual links in a way similar, or the same,
> to the <A HREF="http://...."> link </A> of HTML?
>
> Using Softquad Panorama Free i tried to to that, but with no
> satisfactory results.
> First, I used the <extref> tag with its xpointer attribute in this way:
>
> <extref xpointer="http://hostname/cgi-bin/foo?p1&p2"> link </extref>
>
> but no links were displayed, then I used the <extptr> tag with its href
> attribute in the same way:
>
> <extptr href="http://hostname/cgi-bin/foo?p1&p2"> link </extptr>
>
> In this case Panorama higligth the CDATA of the tag, but it isn't
> treated as an hypertextual link.

I haven't actually done this with the EAD "extref" and "extptr"
elements, but I did manage it with another DTD I was experimenting
with.

I think what you need to do is explicitly tell the application (in
this case the Panorama viewer) to process those specific
element/attribute combinations as the anchor and target of a
hypertext link, and this is done through a "processing instruction",
which can be placed either in the DTD or (perhaps more
appropriately?) in the DTD subset at the start of a document
instance.

My (rather limited) source of information for the form of these
processing instructions is the chapter on "Link types" in the user
guide for Panorama Pro. I don't know whether the more recent Panorama
Publisher package offers more guidance.

For the examples you cite, I'm not sure that the second will parse
correctly as I think "extptr" is defined as an empty element.

For the first example, you could instruct Panorama to process the
value of the "xpointer" attibute of an "extref" element as the target
of a hypertext link through the folowing instruction:

<?ATTLINK extref xpointer URI>

I _think_ Panorama also allows you to indicate that you require this
sort of processing of the "xpointer" attribute of _any_ element which
also has another attribute set to a certain value - but I'm not sure
I ever managed to get that particular combination to work in
practice!

I must qualify all of the above by saying that I have not yet read
the tag library document for version 1.0, and in particular the
description of the semantics of the elements and attributes used to
specify linking, which have been modified/extended to provide
XLink/XPointer support. So, I'm not sure whether "xpointer" would be
the most appropriate attribute to use to specify the target URL, but
_if_ it is then I think the above processing instruction would be
sufficient to get Panorama to process it as such.

Pete Johnston

====================================================
Pete Johnston (Effective Records Management Project)
Archives & Business Records Centre
University of Glasgow
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