XLink example (from W3C Specification)

Example: Sample extended-Type Element Declarations and Instance

Following is a non-normative set of declarations for an extended-type element and its subelements. Parts of this example are reused throughout this specification. Note that the type attribute and some other attributes are defaulted in the DTD in order to highlight the attributes that are changing on a per-instance basis.

<!ELEMENT courseload ((tooltip|person|course|gpa|go)*)>
<!ATTLIST courseload
  xmlns:xlink     CDATA           #FIXED "http://www.w3.org/1999/xlink"
  xlink:type      (extended)      #FIXED "extended"
  xlink:role      CDATA           #IMPLIED
  xlink:title     CDATA           #IMPLIED>

<!ELEMENT tooltip ANY>
<!ATTLIST tooltip
  xlink:type      (title)         #FIXED "title"
  xml:lang        CDATA           #IMPLIED>

<!ELEMENT person EMPTY>
<!ATTLIST person
  xlink:type      (locator)       #FIXED "locator"
  xlink:href      CDATA           #REQUIRED
  xlink:role      CDATA           #IMPLIED
  xlink:title     CDATA           #IMPLIED
  xlink:label     NMTOKEN         #IMPLIED>

<!ELEMENT course EMPTY>
<!ATTLIST course
  xlink:type      (locator)       #FIXED "locator"
  xlink:href      CDATA           #REQUIRED
  xlink:role      CDATA           #FIXED "http://www.example.com/linkprops/course"
  xlink:title     CDATA           #IMPLIED
  xlink:label     NMTOKEN         #IMPLIED>

<!-- GPA = "grade point average" -->
<!ELEMENT gpa ANY>
<!ATTLIST gpa
  xlink:type      (resource)      #FIXED "resource"
  xlink:role      CDATA           #FIXED "http://www.example.com/linkprops/gpa"
  xlink:title     CDATA           #IMPLIED
  xlink:label     NMTOKEN         #IMPLIED>

<!ELEMENT go EMPTY>
<!ATTLIST go
  xlink:type      (arc)           #FIXED "arc"
  xlink:arcrole   CDATA           #IMPLIED
  xlink:title     CDATA           #IMPLIED
  xlink:show      (new
                  |replace
                  |embed
                  |other
                  |none)          #IMPLIED
  xlink:actuate   (onLoad
                  |onRequest
                  |other
                  |none)          #IMPLIED
  xlink:from      NMTOKEN         #IMPLIED
  xlink:to        NMTOKEN         #IMPLIED>

Following is how XML elements using these declarations might look.

<courseload>

  <tooltip>Course Load for Pat Jones</tooltip>

  <person
    xlink:href="students/patjones62.xml"
    xlink:label="student62"
    xlink:role="http://www.example.com/linkprops/student"
    xlink:title="Pat Jones" />

  <person
    xlink:href="profs/jaysmith7.xml"
    xlink:label="prof7"
    xlink:role="http://www.example.com/linkprops/professor"
    xlink:title="Dr. Jay Smith" />
  <!-- more remote resources for professors, teaching assistants, etc. -->

  <course
    xlink:href="courses/cs101.xml"
    xlink:label="CS-101"
    xlink:title="Computer Science 101" />
  <!-- more remote resources for courses, seminars, etc. -->

  <gpa xlink:label="PatJonesGPA">3.5</gpa>

 <go
    xlink:from="student62"
    xlink:to="PatJonesGPA"
    xlink:show="new"
    xlink:actuate="onRequest"
    xlink:title="Pat Jones's GPA" />
  <go
    xlink:from="CS-101"
    xlink:arcrole="http://www.example.com/linkprops/auditor"
    xlink:to="student62"
    xlink:show="replace"
    xlink:actuate="onRequest"
    xlink:title="Pat Jones, auditing the course" />
  <go
    xlink:from="student62"
    xlink:arcrole="http://www.example.com/linkprops/advisor"
    xlink:to="prof7"
    xlink:show="replace"
    xlink:actuate="onRequest"
    xlink:title="Dr. Jay Smith, advisor" />

</courseload>
Helena Ahonen-Myka
Last modified: Thu Apr 5 09:18:30 EET DST 2001