Soft linking allows topics to be reused without broken links by identifying subjects rather than resources. Topics are indexed by subject and links are created by querying the available topics in each use. This prevents broken links because if no topic for a reference is found, no link is created rather than a broken one. It also handles multiple potential link targets by providing options like pop-ups or end-of-topic lists. Soft linking solves problems with hard linking like link maintenance burdens and broken links when topics are reused.

1. No More Broken Links
Mark Baker
Analecta Communications Inc.

2. Why do links break?
 Somebody moved the cheese
A
B
D E
C
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3. Links in HTML
<p>Hawkes‘ final film is a lighthearted
Western in the Rio Bravo mold, with
<a
href="http://www.johnwayne.com/">
the Duke</a> as an ex-Union colonel
out to settle some old scores.</p>
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4. Hard Links
 A hard link identifies a resource to link to
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5. Hard links are hard work
 Author discovers a resource to
link to
 Author creates link to chosen
resource
 Author manages and updates
link over time
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6. Hard Linking
 Topics contain direct links to other
topics
A
B
D E
C
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7. The problem with hard linking
 If a topic is reused in more than one
location, what do you do about the links?
A
B
D E
C
First use
A
D
C
Second use
F
?
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8. Remove all the links?
 Lonely topics
A
B
D E
C
A
D
C
First use Second use
F
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9. Externalize the links
 Move the links to a map file
 New map file required for each use
 Heavy creation and maintenance burden
 Will tend to limit amount of linking that is practical
First use Second use
Map file for first use
A  B
A  C
A  D
A  E
Map file for second use
A  C
A  D
A  F
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10. Soft linking
 A soft link identifies the subject that
is mentioned
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11. Soft links in XML
<p><director name="Howard
Hawkes">Hawkes'</director> final
film is a lighthearted Western in the
<movie>Rio Bravo</movie> mold,
with <actor name="John Wayne">the
Duke</actor> as an ex-Union colonel
out to settle some old scores.</p>
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12. How do links get made
 Topics are indexed by subject
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13. Topic indexing in XML
<topic name="john-wayne-bio">
<index>
<reference type="actor">
<key>John Wayne</key>
</reference>
<reference type="producer">
<key>John Wayne</key>
</reference>
</index>
…
</topic>
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14. Links discovered via topic indexes
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15. Soft linking != redirection
 No resource is identified in any way
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16. Connection is by subject only
 No resource has to exist to name a
subject
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17. Soft linking and reuse
 Links are created by querying the available
topics in each place a topic is used
A
B
D E
C
First use Second use
A
D
C
F
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18. What if no topic found?
 Sometime there will be no topic in the
current set for a reference
A
D
C
F
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19. Not topic, no link!
 No broken link, because no link to
break
A
D
C
F
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20. What if multiple topics found?
 More than one topic can cover the same subject
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21. Handling multiple link targets 1
 Create a popup
with multiple links
Topics on John
Wayne
• Filmography
• Biography
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22. Handling multiple link targets 2
 Gather all the links
at the end of the
topic
More on John Wayne
• Filmography
• Biography
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23. Questions?
 Contact information
 Mark Baker
 Analecta Communications Inc.
 mbaker@analecta.com
 Twitter: @mbakeranalecta
 Company: http://analecta.com
 Blog: http://everypageispageone.com
 Book: http://xmlpress.net/publications/eppo/
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