Re: A microSchema Was: [xml-dev] MicroXSD for MicroXML?

[Stephen Green <stephengreenubl@gmail.com>]

In writing an XSD schema using MicroXML
the issue was in declaring globals (groups,
attributes or elements) without the use of
XML namespace prefixes. I would need,
I think, to have more than one namespace
declaration in the schema - one for the
schema itself and another for the standard
"http://www.w3.org/2001/XMLSchema";.

There seems to be no problem just having
local elements and attributes but this does
limit greatly what I can do with the schema.

Maybe another answer would be to be allowed
to define such a MicroXSD schema without
the "http://www.w3.org/2001/XMLSchema";
namespace - but then, I guess, existing XSD
tools would be unlikely to 'understand' it.

It seems to me that if a MicroRNG does not
require the use of a RelaxNG namespace then
it might have an edge on a 'MicroXSD' profile
as it would leave open the possibility to add
a user-defined namespace without any prefix
using just the simple 'xmlns' attribute.

----
Stephen D Green



On 22 December 2010 09:59, Stephen Green
<stephen.green@documentengineeringservices.com> wrote:
> After issues trying to produce a MicroXML XSD schema
> which is at least self-valid/self-validating and functional
> I concluded that the requirements regarding namespaces
> for full XML Schema v1 compatibility not really compatible
> with the concept of a MicroXML. Rather than give up, I
> went for a compromise which resulted in an actual
> MicroXML instance with the same syntax (and, I hope,
> same semantics albeit modified somewhat for MicroXML)
> as W3C XML Schema but not actually executable in
> W3C XML Schema tools: It would require new, hopefully
> lightweight / MicroXML-ish, tools to use it to validate a
> MicroXML instance. I guess it cannot be called XSD so I
> would dub it a microSchema (XSD-esque?) describing
> itself but relying on reference to XSD (W3C XML Schema)
> for its semantics. (Again, no guarantees about it being
> worthy of actual use or error-free...). The bindings to any
> datatypes are left out of the schema and would be applied
> separately (Micro-Genericode??? :-); it does includes 'string'
> - in the spirit of minimalism and text-centric MicroXML.
>
> Regards
>
> Stephen D Green
>
> <schema>
>        <!-- start of root element -->
>        <element name="schema">
>                <complexType>
>                        <group ref="schema_group" minOccurs="0" maxOccurs="unbounded"/>
>                        <attribute name="version" type="string" use="optional"/>
>                        <attribute name="attributeFormDefault" type="string" use="optional"/>
>                        <attribute name="elementFormDefault" type="string" use="optional"/>
>                </complexType>
>        </element>
>        <!-- end of root element -->
>        <group name="schema_group">
>                <choice>
>                        <element ref="element"/>
>                        <element ref="attribute"/>
>                        <element ref="group"/>
>                </choice>
>        </group>
>        <element name="element">
>                <complexType>
>                        <group ref="element_group" minOccurs="0"/>
>                        <attribute ref="ref" use="optional"/>
>                        <attribute ref="name" use="optional"/>
>                        <attribute ref="type" use="optional"/>
>                        <attribute ref="minOccurs" use="optional"/>
>                        <attribute ref="maxOccurs" use="optional"/>
>                </complexType>
>        </element>
>        <attribute name="ref" type="string"/>
>        <attribute name="name" type="string"/>
>        <attribute name="type">
>                <simpleType>
>                        <restriction base="string"/>
>                </simpleType>
>        </attribute>
>        <attribute name="minOccurs">
>                <simpleType>
>                        <restriction base="string">
>                                <enumeration value="0"/>
>                                <enumeration value="1"/>
>                        </restriction>
>                </simpleType>
>        </attribute>
>        <attribute name="maxOccurs">
>                <simpleType>
>                        <restriction base="string">
>                                <enumeration value="1"/>
>                                <enumeration value="unbounded"/>
>                        </restriction>
>                </simpleType>
>        </attribute>
>        <element name="attribute">
>                <complexType>
>                        <group ref="attribute_group" minOccurs="0"/>
>                        <attribute ref="use" use="optional"/>
>                        <attribute ref="ref" use="optional"/>
>                        <attribute ref="name" use="optional"/>
>                        <attribute ref="type" use="optional"/>
>                </complexType>
>        </element>
>        <attribute name="use">
>                <simpleType>
>                        <restriction base="string">
>                                <enumeration value="optional"/>
>                                <enumeration value="required"/>
>                        </restriction>
>                </simpleType>
>        </attribute>
>        <element name="group">
>                <complexType>
>                        <group ref="group_group" minOccurs="0"/>
>                        <attribute ref="ref" use="optional"/>
>                        <attribute ref="name" use="optional"/>
>                        <attribute ref="minOccurs" use="optional"/>
>                        <attribute ref="maxOccurs" use="optional"/>
>                </complexType>
>        </element>
>        <group name="group_group">
>                <choice>
>                        <element ref="choice"/>
>                </choice>
>        </group>
>        <element name="choice">
>                <complexType>
>                        <group ref="choice_group" minOccurs="0" maxOccurs="unbounded"/>
>                </complexType>
>        </element>
>        <group name="choice_group">
>                <choice>
>                        <element ref="element"/>
>                        <element ref="group"/>
>                </choice>
>        </group>
>        <group name="element_group">
>                <choice>
>                        <element ref="complexType"/>
>                        <element ref="simpleType"/>
>                </choice>
>        </group>
>        <group name="attribute_group">
>                <choice>
>                        <element ref="simpleType"/>
>                </choice>
>        </group>
>        <element name="complexType">
>                <complexType>
>                        <group ref="complexType_group" minOccurs="0" maxOccurs="unbounded"/>
>                        <attribute ref="mixed" use="optional"/>
>                </complexType>
>        </element>
>        <group name="complexType_group">
>                <choice>
>                        <element ref="attribute"/>
>                        <element ref="group"/>
>                </choice>
>        </group>
>        <attribute name="mixed">
>                <simpleType>
>                        <restriction base="string">
>                                <enumeration value="true"/>
>                                <enumeration value="false"/>
>                        </restriction>
>                </simpleType>
>        </attribute>
>        <element name="simpleType">
>                <complexType>
>                        <group ref="simpleType_group"/>
>                </complexType>
>        </element>
>        <group name="simpleType_group">
>                <choice>
>                        <element ref="restriction"/>
>                </choice>
>        </group>
>        <element name="restriction">
>                <complexType>
>                        <group ref="restriction_group" minOccurs="0" maxOccurs="unbounded"/>
>                        <attribute ref="base" use="optional"/>
>                        <attribute ref="value" use="optional"/>
>                </complexType>
>        </element>
>        <attribute name="value" type="string"/>
>        <group name="restriction_group">
>                <choice>
>                        <element ref="enumeration"/>
>                </choice>
>        </group>
>        <element name="enumeration">
>                <complexType>
>                        <attribute ref="value" use="required"/>
>                </complexType>
>        </element>
>        <attribute name="base">
>                <simpleType>
>                        <restriction base="string"/>
>                </simpleType>
>        </attribute>
> </schema>
>