DBCacheContrib

Reusable code that treats TWiki forms as if they were table rows in a database.

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   PLEASE DO NOT EDIT THIS TOPIC

   It is automatically generated from the subversion repository, and any
   changes you make will simply be overwritten the next time a release is
   generated.

   Instead, you could check your fix in, raise a bug in the Bugs web, or
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Summary of Contents

This module supports structured queries over a database built on the fly from the forms in TWiki topics. It does not support any tags, as it is provided as a service for other plugins that want to treat a TWiki web as a simple database; for example, the Plugins/FormQueryPlugin, which supports the display of query results.

The plugin encapsulates code that was formerly in the "engine room" of the FormQueryPlugin. It has been abstracted out in the belief that it will be useful to anyone who wants to do simple search operations from a plugin.

Features

• Perform complex queries on the TWiki database
• Cache TWiki topics for rapid queries

How the database gets built

Each topic in the web automatically gets a number of standard fields, generated by reading the metadata from the topic (see TWikiMetaData)

• name - name of the topic
• parent - name of parent topic
• _up - reference to the Map of the parent topic, if it exists
• attachments - array of Maps, each of which contains:
  • _up - reference to the Map for the topic
  • name - attachment name
  • attr - e.g hidden
  • comment - attachment comment
  • path - client path used to upload attachment
  • size - size in Kb
  • user - who uploaded the attachment
  • version - e.g. 1.3
• info - Map containing:
  • _up - reference to the Map for the topic
  • author - most recent author
  • date - date of last change
  • format - topic format version
  • version - topic version number
• moved - Map containing:
  • _up - reference to the Map for the topic
  • by - who moved it
  • date - when they moved it
  • from - where they moved it from
  • to - where they moved it to
• form - form type
• form name - e.g. if a "MyForm" is attached, this will be MyForm. This is a reference to a Map containing a key for each field in the form. Each key maps to the value in the form data for that key. The Map will also have an _up reference to the Map for the topic.
• text - raw text of the topic)

The sub-Maps created for info, form name, moved, and each row in attachments also have a reference back to the topic Map, called _up.

Other fields may be added by subclasses. Refer to the documentation for the plugin that is using the DBCache for more details.

The cache

Extending or customising

The module is shipped with a perl build file, which should be used for installation and testing. Testing is done using Test::Unit, and is invoked using the 'test' build target. Writing tests is a useful way of feeding back bugs as well. I can't encourage you enough to maintain and extend the tests!

Detailed Documentation

%$POD%

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 Set STUB = %$STUB%
 
 Set SHORTDESCRIPTION = Reusable code that treats TWiki forms as if they were table rows in a database
 
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Installation Instructions

{DBCache}{AlwaysUpdateCache}

%$INSTALL_INSTRUCTIONS%

Contrib Info