- From: Henry S. Thompson <ht@cogsci.ed.ac.uk>
- Date: 08 May 2001 08:39:19 +0100
- To: "Roger L. Costello" <costello@mitre.org>
- Cc: xmlschema-dev@w3.org
"Roger L. Costello" <costello@mitre.org> writes:
> "Henry S. Thompson" wrote:
> >
> > Sure there is -- just <import> the namespace, with no
> > 'schemaLocation'. You've now issued a promise that at runtime someone
> > will supply types in that namespace (if indeed you use them), but that
> > promise won't come due _until_ runtime. No problem.
>
> Awesome! So, the weather station schema would look like this:
>
> weather-station.xsd
> ----------------------------------------------------
> <?xml version="1.0"?>
> <xsd:schema xmlns:xsd="http://www.w3.org/2000/10/XMLSchema"
> targetNamespace="http://www.weather-station.org"
> xmlns="http://www.weather-station.org"
> xmlns:s="http://www.sensor.org"
> elementFormDefault="qualified">
> <xsd:import namespace="http://www.sensor.org"/>
> <xsd:element name="weather-station">
> <xsd:complexType>
> <xsd:sequence>
> <xsd:element name="sensor" type="s:sensor_type"
> maxOccurs="unbounded"/>
> </xsd:sequence>
> </xsd:complexType>
> </xsd:element>
> </xsd:schema>
> ----------------------------------------------------
>
> Note that the <import> element does not have a schemaLocation. Each
> application provides its own definition of sensor_type, e.g.,
>
> london-sensors.xsd
> ----------------------------------------------------
> <?xml version="1.0"?>
> <xsd:schema xmlns:xsd="http://www.w3.org/2000/10/XMLSchema"
> targetNamespace="http://www.sensor.org"
> xmlns="http://www.sensor.org"
> elementFormDefault="qualified">
> <xsd:simpleType name="sensor_type">
> <xsd:restriction base="xsd:string">
> <xsd:enumeration value="barometer"/>
> <xsd:enumeration value="thermometer"/>
> <xsd:enumeration value="anenometer"/>
> <xsd:enumeration value="hygrometer"/>
> </xsd:restriction>
> </xsd:simpleType>
> </xsd:schema>
>
> Instance documents will reference both schemas:
>
> london-weather-station.xml
> ----------------------------------------------------
> <?xml version="1.0"?>
> <weather-station xmlns="http://www.weather-station.org"
> xmlns:xsi="http://www.w3.org/2000/10/XMLSchema-instance"
> xsi:schemaLocation=
> "http://www.weather-station.org weather-station.xsd
> http://www.sensor.org london-sensors.xsd">
> <sensor>thermometer</sensor>
> <sensor>barometer</sensor>
> <sensor>hygrometer</sensor>
> <sensor>anenometer</sensor>
> </weather-station>
> ----------------------------------------------------
>
> Do I now have a correct understanding?
Yes.
ht
--
Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
W3C Fellow 1999--2001, part-time member of W3C Team
2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk
URL: http://www.ltg.ed.ac.uk/~ht/
Received on Tuesday, 8 May 2001 03:39:22 UTC