XLink Visualization

Web-Based Publishing (INFO 290-19)

Erik Wilde, UC Berkeley School of Information
2007-04-10
Creative Commons License

This work is licensed under a Creative Commons
Attribution-NonCommercial-ShareAlike 2.5 License.

Abstract

Even though XLink is an interesting and sufficient foundation for the project of this course, it does have some problems for the AJAXLink application. The most important observation is that XLink is underspecified and missing important complementary specifications in various areas. The two most important areas are linkbase access (how to selectively retrieve XLinks) and link visualization (how to render a link once it has been retrieved). This lecture proposes a simple XLink visualization algorithm.

Outline (XLink Problems)

  1. XLink Problems [3]
  2. XLink Basic Display [6]
  3. XLink Styling [3]
  4. Conclusions [1]

XLink Fundamental Problems

XLink Navigational Problems

What is an XLink?

  1. An XLink may play a role (the Semantic Attribute role)
  2. An XLink may have a title (as simple attribute or using title children)
  3. XLinks contain sets of resources (identified by locator or embedded as resource)
  4. External resources may use Fragment Identifiers
  5. Each resource may play a role (the Semantic Attribute role)
  6. Each resource may have a title (as simple attribute or using title children)
  7. Arcs connect resources based on label/from/to
  8. Arcs may play a role (the Semantic Attribute arcrole)
  9. Each arc may have a title (as simple attribute or using title children)
  10. Arc behavior can be controlled by Behavior Attributes (show and actuate)
  11. The resulting structure has to be made navigable from the current resource

Outline (XLink Basic Display)

  1. XLink Problems [3]
  2. XLink Basic Display [6]
  3. XLink Styling [3]
  4. Conclusions [1]

Abstract Navigation

XLink Interaction and Interface

XLink Rendering Algorithm

  1. Compute the effective navigational structure and start from the current resource
  2. If any onLoad is found, no interactive navigation is required
    • the exact same actions should be carried out as in the case of interactive navigation
    • multiple onLoad arcs probably should be considered an error
  3. Collect all outgoing arcs (where the from is equal to label)
    • sorting them is not possible using standard XLink attributes (no sort order information)
  4. For each arc, create a first-level navigation structure
    • use the title as text for the entry
    • if present, use the arcrole as additional information (maybe used for styling)
  5. For each arc, create a second-level navigation structure for each target resource (label=to)
    • use the title as text for the entry
    • if present, use the role as additional information (maybe used for styling)

Link Interaction Language (LIL)

Blinkbase LIL

<?xml version="1.0" encoding="UTF-8"?>
<links>
 <link start="http://docordie.blogspot.com/2006/08/sorry-pluto-and-some-thoughts-about.html" title="Sorry Pluto… And Some Thoughts About Categorization">
  <first title="Post Time">
   <second>2006-08-27</second>
  </first>
  <first title="Post Author">
   <second title="Bob Glushko" href="http://www.ischool.berkeley.edu/~glushko/" />
  </first>
  <first title="Blog Home">
   <second title="Doc Or Die" href="http://docordie.blogspot.com/" />
  </first>
 </link>
 <link start="http://docordie.blogspot.com/2006/08/sorry-pluto-and-some-thoughts-about.html" title="Category Craziness in &#34;Decapod Duels&#34;">
  <first title="Related Post">
   <second title="Category Craziness in &#34;Decapod Duels&#34;" href="http://docordie.blogspot.com/2006/12/category-craziness-in-decapod-duels.html" />
  </first>
 </link>
</links>

Interaction to Interface

Outline (XLink Styling)

  1. XLink Problems [3]
  2. XLink Basic Display [6]
  3. XLink Styling [3]
  4. Conclusions [1]

Controlling XLinks

Interaction Styling

Interface Styling

Outline (Conclusions)

  1. XLink Problems [3]
  2. XLink Basic Display [6]
  3. XLink Styling [3]
  4. Conclusions [1]

Declarativity Needs Configurability