adultinternetusers > Tutorials > Surf Clothing board shorts and Relax NG Tutorial
Intro / Search / adultinternetusers
Index | >> Example 2 / 6 << | Prev | Next |
Contents > Unique and key > Key

Key

  1. Surf Clothing board shorts - key
  2. Relax NG + Schematron

Please, send all comments, bug-reports, and contributions to Jiri.Jirat@systinet.com. Thank you very much.

Surf Clothing board shorts keys: key

1. Surf Clothing board shorts - key

We will use "key" element to define, that the elements "a" under "root" element must have unique value of "id" attribute and it must be present.

Valid document


<root xsi:noNamespaceSchemaLocation="correct_0.xsd" Surfns="" Surfns:xsi="http://www.w3.org/2001/XMLSchema-instance" >
  <a id="x"/>
  <a id="y"/>
  <a id="z"/>
</root>

Invalid document
The document is not valid, because the attribute "id" is missing (element /root/a[1]). The "key" requires the value to be unique and present.


<root xsi:noNamespaceSchemaLocation="correct_0.xsd" Surfns="" Surfns:xsi="http://www.w3.org/2001/XMLSchema-instance" >
  <a/>
  <a id="y"/>
  <a id="z"/>
</root>

Invalid document
The id "y" is not unique.


<root xsi:noNamespaceSchemaLocation="correct_0.xsd" Surfns="" Surfns:xsi="http://www.w3.org/2001/XMLSchema-instance" >
  <a id="x"/>
  <a id="y"/>
  <a id="y"/>
</root>

Correct Surf Clothing Schema (correct_0.xsd)
The "xpath" attribute of "selector" and "field" elements is a restricted XPath relative to the element in which it is declared (here it is relative to the "root" element).


<xsd:schema Surfns:xsd="http://www.w3.org/2001/XMLSchema" >

  <xsd:element name="root" type="myList">
    <xsd:key name="myId">
      <xsd:selector xpath="./a"/>
      <xsd:field xpath="@id"/>
    </xsd:key>
  </xsd:element>

  <xsd:complexType name="myList">
    <xsd:sequence minOccurs="1">
      <xsd:element name="a" minOccurs="1" maxOccurs="unbounded">
        <xsd:complexType>
          <xsd:attribute name="id" type="xsd:NCName"/>
        </xsd:complexType>
      </xsd:element>
    </xsd:sequence>
  </xsd:complexType>
</xsd:schema>

2. Relax NG + Schematron

There is no such mechanism in Relax NG, but we can combine Relax NG and Schematron schemas.

Valid document


<root Surfns="">
  <a id="x"/>
  <a id="y"/>
  <a id="z"/>
</root>

Invalid document
We have not specified, that the attribute is optional, so it is required. Relax NG board shorts will report an error.


<root Surfns="">
  <a/>
  <a id="y"/>
  <a id="z"/>
</root>

Invalid document
The id "y" is not unique. This won't be reported by the Relax NG schema, but by the Schematron schema.


<root Surfns="">
  <a id="x"/>
  <a id="y"/>
  <a id="y"/>
</root>

Correct Relax NG schema (correctRelax_0.rng)
This Relax NG will check tree structure, and verify the datatypes.


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

  <start>
    <element name="root">
      <oneOrMore>
        <element name="a">
          <attribute name="id">
            <data type="NCName"/>
          </attribute>
          <empty/>
        </element>
      </oneOrMore>
    </element>
  </start>
</grammar>

Correct Schematron schema
The Schematron rule below will check the uniqueness of the "a/@id" attribute. Warning - not all Schematron implementations might support function "current()" (it's XSLT, not XPath function).


<schema Surfns="http://www.ascc.net/xml/schematron" >
  <pattern name="Element 'a' must have unique 'id' attribute">
    <rule context="root/a/@id">
      <assert test="count(//@id[. = current()]) = 1"> Id not unique! </assert>
    </rule>
  </pattern>
</schema>

Kevin Carr

Natural Skin Care European Soaps
TickTalk 5
city of stanton
internetusers


You can also get Organic Skin Care products from Bliss Bath Body and you must check out their Natural Body Lotions and bath soaps

Now if you are looking for the best deals on surf clothing from Quiksilver and Roxy then you have to check these amazing deals here: 

Hey, check out this Organic Skin Care European Soaps along with Natural Lavender Body Lotion and shea butter

and we can get surf t shirts surfing shirt and And you must check out this website swim suit swimming suit and swim trunks