Architectural Form Processing
The Hytime standard (ISO/IEC 10744) introduced the concept of
architectural forms. This document assumes you are already familiar
with this concept. The first Technical Corrigendum to HyTime, which is
soon to be published, generalizes this, and makes it possible to have
an architecture engine which can perform architectural form
processing for arbitrary architectures. SP now includes such an
Non-markup sensitive applications built using SP now support
architectural form processing using the -A
archname option. When this option is specified, the
document will be validated against all declared base architectures,
and the output will be for the architectural document for that
architecture: the element types, notations and attributes will be
those defined in the meta-DTD.
This option is experimental and has not been subject to much testing.
Please be sure to report any bugs or problems you encounter.
Although spam does not support the -A option because it
works with the markup of your document, sgmlnorm does.
Architectural Support Attributes
To use the -A option with a document, you must add must add:
an architecture base declaration for archname, and
architectural support attributes for archname
An architecture base declaration is a processing instruction of the form:
The processing instruction is recognized either in the DTD or in an
You can specify architectural support attributes in several different
by an attribute definition list for a notation
archname in the DTD; the default values in the
attribute definition list provide the values for the support
as link attributes on the document element in a simple link process;
as link attributes of the document element type in the initial link
set in an implicit or explicit link process; note that there must be a
link rule for the document element type in the initial link set even
if all the attributes can be defaulted.
If the architectural support attributes are specified as link
attributes, then they must occur in the same LPD as the architecture
base declaration occurred, if it occurred in an LPD, and otherwise in
the LPD must be named archname.
The -A archname option automatically activates
any link type archname.
Note that SGML does not allow a notation declaration in a link type
The following architectural support attributes are recognized:
The name of the document element type in the meta-DTD.
This would be HyDoc for HyTime.
This defaults to archname.
The name of an external parameter entity that contains the meta-DTD.
The declared value of this attribute should be CDATA: it can't be
ENTITY, because the value of a ENTITY attribute has to be a data or
subdoc entity; it can't be any other kind of tokenized attribute,
because general name substitution would be done to it. By default,
if a notation archname was declared
with a formal public identifier,
the meta-DTD will be treated as if it had been declared:
<!DOCTYPE ArcDocF PUBLIC pubid>
where pubid is the public identifier specified
for the notation with the public text class changed from
NOTATION to DTD; otherwise it will be
treated as if it had been declared
<!DOCTYPE ArcDocF SYSTEM>
The name of the attribute that elements use to specify the
corresponding element type, if any, in the meta-DTD.
Data entities also use this attribute to specify the corresponding
notation in the meta-DTD.
This would be HyTime for HyTime.
This defaults to archname.
The name of the attribute that elements use to specify substitutes for
the names of attributes in the meta-DTD. A value of
#DEFAULT is allowed for a substitute name; this inhibits
mapping of an attribute to an architectural attribute, but specified
that the value of the architectural attribute should be defaulted
rather than taken from the value of another attribute in the document.
For HyTime the value of this attribute would be HyNames.
By default no attribute name substitutition is done.
The name of an attribute that elements may use to suppress processing
of their descendants. This attribute is not recognized for data
entities. The value of the attribute must be one of the following
Completely suppress all architectural processing of descendants.
It is not possible to restore architectural processing
for a descendant.
Suppress processing of the ArcFormA attribute of all
descendants of this element, except for those elements that have a
non-implied ArcSuprA attribute.
Don't suppress architectural processing for the descendants of
The value may also be implied, in which case the state of
architectural processing is inherited.
If an element has an ArcSuprA attribute that was processed, its
ArcFormA attribute will always be processed. Otherwise its ArcFormA
attribute will be processed unless its closest ancestor that has a
non-implied value for the ArcSuprA attribute suppressed processing of
the ArcFormA attribute. An element whose ArcFormA attribute is
processed will not be treated as architectural if it has an implied
value for the ArcFormA attribute.
The name of the element type in the meta-DTD that suppresses
architectural processing in the same manner as does the
sHyTime form in HyTime. By default, no element type
does. This behaves like an element with an
ArcSuprA attribute of sArcForm. The element
type should be declared in the meta-DTD. You should not specify a
value for this attribute if you specified a value for the
The name of a default element type declared in a meta-DTD,
to which elements in the document should be automatically mapped
if they have an ID and would not otherwise be considered
This would be HyBrid for HyTime.
If your meta-DTD declares IDREF attributes, it will
usually be appropriate to specify a value for
ArcBridF, and to declare an ID attribute
for that form in your meta-DTD.
The name of a default notation declared in the meta-DTD,
to which the external data entities in the document
should be automatically mapped if they would
not otherwise be considered architectural.
If this attribute is defined,
then general entities will be automatically architectural:
any external data entity whose notation cannot otherwise be mapped
into a notation in the meta-DTD will be automatically treated
as an instance of the ArcDfltN notation.
This would be data for HyTime.
If your meta-DTD declares entity attributes, it will usually
be appropriate to specify a value for ArcDfltN
even if your meta-DTD declares no data attributes for the
This must have one of the following values:
If an element does not have an ArcFormA attribute and the
meta-DTD defines an element type with the same name as the element's
type, the element will be automatically treated as being an instance
of the meta-type. This rule does not apply to the
document element type; this is automatically treated as being an
instance of the meta-DTD's document element type.
Note that this automatic mapping is prevented if
the element has an ArcFormA attribute with an implied
value. It is also prevented if processing of the
ArcFormA attribute is suppressed. This applies equally
to the notations of external data entities.
The default element or notation specified with the
ArcBridF or ArcDfltN attribute
is only considered after the mapping specified by ArcAuto.
Automatic mapping is not performed.
The default value is ArcAuto.
A meta-DTD is allowed to use the following extensions:
a single element type or notation is allowed to be an associated
element type or associated notation name for multiple attribute
#ALL can be used as an associated element type
or associated notation name in an attribute definition list
to define attributes for all element types or notations
in the meta-DTD
In all other respects a meta-DTD must be a valid SGML DTD.
A meta-DTD is interpreted using the SGML declaration of the document.
A declared value of ENTITY for an attribute in a meta-DTD means that
the value of the attribute must be an entity declared in
the (non-meta) DTD that is architectural.
An external data entity is architectural only if its notation can be
mapped into a notation in the meta-DTD.
All other kinds of data and subdoc entities are automatically
An IDREF attribute in the meta-document must have a corresponding ID
in the meta-document. An attribute with a declared value of ID in the
document will be automatically mapped to an attribute with a declared
value of ID in the meta-DTD.
A declared value of NOTATION in the meta-DTD means that the value of
the attribute must have one the values specified in the name group and
that it must be a notation in the meta-DTD.
(Perhaps if the attribute also has a declared value of NOTATION
in the non-meta-DTD, the value should be mapped in a similar
way to the notation of an external data entity.)
Differences from HyTime
There are a number of differences from how architectural processing is
defined in the pre-Corringendum version of the HyTime standard.
The ArcNamrA and ArcFormA attributes are not
part of the meta-DTD. Rather they are used by the architecture engine
in deriving the meta-document that is validated against the meta-DTD.
The use: conventional comment is not recognized. Instead
a single element type is allowed to be an associated element type for
multiple attribute definition lists.
The notation and data attributes of an external data entity are
treated just like the element type and attributes of an element. The
notation of an external data entity is mapped into a notation in the
meta-DTD and the data attributes of the entity are mapped onto
attributes defined for the meta-DTD notation.
#FIXED has the same meaning in a meta-DTD that it does in
a regular DTD: the value of the attribute must be the same as the
default value of the attribute specified in the meta-DTD.
Data is only treated as architectural if it occurs in a context
in which the meta-DTD allows data.
Link attributes defined by an implicit link process are treated in the
same way as non-link attributes. The only complication is that SGML
allows link attributes to have the same name as non-link attributes.
If there is a link attribute and a non-link attribute with the same
name, the architecture engine will only look at the link attribute,
even if the value of the link attribute is implied. The only
exception is the ArcNamrA attribute: the architecture
engine will use both the link attribute and the non-link attribute,
but the substitute names in the value of the non-link attribute cannot
refer to link attribute names.
Notation set architecture
An architecture for which archname is declared
as a notation with a public identifier of
"ISO/IEC 10744//NOTATION Notation Set Architecture//EN"
is special. The element types in the meta-DTD for this architecture
are the notations of the document DTD and the attributes defined for
the element types in the meta-DTD are the data attributes defined for
the notations in the document DTD. For each element, the attribute
with a declared value of NOTATION performs the function that the
ArcFormA attribute performs for normal architectures. Only the
ArcNamrA and ArcSuprA architectural support
attributes can be used with this architecture.
The notation set acrhitecture can also be declared using
an architecture base declaration of the form:
In this case, no architecture support attributes can be declared;
ArcNamrA will be defaulted to notnames.
A meta-DTD can have one or more base architectures in the same way as
a normal DTD. Multiple -A options can be used to exploit
this. For example,
-A arch1 -A arch2
will perform architectural processing on the source document to
produce an architectural document conforming to the architecture
arch1 declared in the source document, and
will then perform architectural processing on this architectural
document to produce an architectural document conforming to the
arch2 architecture declared in
A document that is validated against a meta-DTD will automatically
be validated against any base architectures of that meta-DTD.