Oxygen XML Forum

Posted: **Wed Jul 28, 2004 5:06 pm**

Hey, George !! I have another one:

I am trying to define a schema for Latitide/Longitude such that it can be expressed as degrees, minutes, and seconds.

Normally, the restrictions would be (for latitude) degrees > 90, minutes > 60, and seconds > 60

The problem is that 90d0m0s is also a valid latitude.

My colleague who swears by XML Spy (while I just swear at it) came up with this:

Code: Select all


<?xml version="1.0" encoding="UTF-8"?>

<!-- edited with XMLSPY v2004 rel. 4 U (http://www.xmlspy.com) by Dan White (NGIT-DMS) -->

<xs:schema elementFormDefault="qualified" attributeFormDefault="unqualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">

	<xs:complexType name="LatitudeType">

		<xs:choice>

			<xs:sequence>

				<xs:element name="deg">

					<xs:simpleType>

						<xs:restriction base="xs:decimal">

							<xs:maxInclusive value="90"/>

						</xs:restriction>

					</xs:simpleType>

				</xs:element>

				<xs:element name="min" type="xs:decimal" fixed="0"/>

				<xs:element name="sec" type="xs:decimal" fixed="0"/>

				<xs:element name="dir">

					<xs:simpleType>

						<xs:restriction base="xs:string">

							<xs:enumeration value="N"/>

							<xs:enumeration value="n"/>

							<xs:enumeration value="S"/>

							<xs:enumeration value="s"/>

						</xs:restriction>

					</xs:simpleType>

				</xs:element>

			</xs:sequence>

			<xs:sequence>

				<xs:element name="deg">

					<xs:simpleType>

						<xs:restriction base="xs:decimal">

							<xs:minInclusive value="0"/>

							<xs:maxExclusive value="90"/>

						</xs:restriction>

					</xs:simpleType>

				</xs:element>

				<xs:element name="min">

					<xs:simpleType>

						<xs:restriction base="xs:decimal">

							<xs:minInclusive value="0"/>

							<xs:maxExclusive value="60"/>

						</xs:restriction>

					</xs:simpleType>

				</xs:element>

				<xs:element name="sec" fixed="0">

					<xs:simpleType>

						<xs:restriction base="xs:decimal">

							<xs:minInclusive value="0"/>

							<xs:maxExclusive value="60"/>

						</xs:restriction>

					</xs:simpleType>

				</xs:element>

				<xs:element name="dir">

					<xs:simpleType>

						<xs:restriction base="xs:string">

							<xs:enumeration value="N"/>

							<xs:enumeration value="n"/>

							<xs:enumeration value="S"/>

							<xs:enumeration value="s"/>

						</xs:restriction>

					</xs:simpleType>

				</xs:element>

			</xs:sequence>

		</xs:choice>

	</xs:complexType>

</xs:schema>

Oxygen says it is invalid.

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E cos-element-consistent: Error for type 'LatitudeType'. Multiple elements with name 'deg', with different types, appear in the model group.

E cos-nonambig: "":deg and "":deg (or elements from their substitution group) violate "Unique Particle Attribution". During validation against this schema, ambiguity would be created for those two particles.

Is there a valid way to to this ?

Posted: **Thu Jul 29, 2004 11:43 am**

Hi Dan,

As you already found out on the xml-dev list [1] oXygen is right in reporting these errors and more, you cannot represent these kind of constraints in XML Schema.

Oxygen has support also for Relax NG [2] and you can do this easily in a Relax NG schema. In compact syntax that will look like:

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namespace a = "http://relaxng.org/ns/compatibility/annotations/1.0"



start = element latitude { LatitudeType }

LatitudeType =

  (element deg { "90" },

   element min { "0" },

   element sec { "0" },

   dir)

  | (element deg {

       xsd:decimal { minInclusive = "0" maxExclusive = "90" }

     },

     element min {

       xsd:decimal { minInclusive = "0" maxExclusive = "60" }

     },

     element sec {

       xsd:decimal { minInclusive = "0" maxExclusive = "60" }

     },

     dir)

dir = element dir { "s" | "S" | "n" | "N" }

and in xml syntax it is:

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<?xml version="1.0" encoding="UTF-8"?>

<grammar xmlns="http://relaxng.org/ns/structure/1.0" xmlns:a="http://relaxng.org/ns/compatibility/annotations/1.0" datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">

    <start>

        <element name="latitude">

            <ref name="LatitudeType"/>

        </element>

    </start>

    <define name="LatitudeType">

        <choice>

            <group>

                <element name="deg"><value>90</value></element>

                <element name="min"><value>0</value></element>

                <element name="sec"><value>0</value></element>

                <ref name="dir"/>

            </group>

            <group>

                <element name="deg">

                    <data type="decimal">

                        <param name="minInclusive">0</param>

                        <param name="maxExclusive">90</param>

                    </data>

                </element>

                <element name="min">

                    <data type="decimal">

                        <param name="minInclusive">0</param>

                        <param name="maxExclusive">60</param>

                    </data>

                </element>

                <element name="sec">

                    <data type="decimal">

                        <param name="minInclusive">0</param>

                        <param name="maxExclusive">60</param>

                    </data>

                </element>

                <ref name="dir"/>

            </group>

        </choice>

    </define>

    <define name="dir">

        <element name="dir">

            <choice>

                <value>s</value>

                <value>S</value>

                <value>n</value>

                <value>N</value>

            </choice>

        </element>

    </define>

</grammar>

[1] http://lists.xml.org/archives/xml-dev/2 ... 00251.html
[2] http://www.relaxng.org/

Best Regards,
George

Posted: **Thu Jul 29, 2004 4:13 pm**

Thanks for the reply, George.

I am just getting comfortable messing with schema, I am not sure I want to complicate matters by adding new things to it.

Besides, as I mentioned in my other thread, I am planning to use the Xerces C++ library to utilize these schemas for message exchange. Unless Xerces supports this RelaxNG, I will just use my fallback of typing my latitudes and longitudes as single, decimal numbers that I can easily restrict as opposed to triplets of numbers that are proving difficult to validate.

I will look at RelaxNG for future considerations.

Again, thanks for your help.

Oxygen XML Forum

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