Edgewall Software

Changes between Version 3 and Version 4 of TracDev/PluginDevelopment/ExtensionPoints/trac.env.IEnvironmentSetupParticipant


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Timestamp:
May 12, 2010, 8:42:11 PM (14 years ago)
Author:
Carsten Klein <carsten.klein@…>
Comment:

Added more content to the additional information and references section

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  • TracDev/PluginDevelopment/ExtensionPoints/trac.env.IEnvironmentSetupParticipant

    v3 v4  
    4747   This is the setup participant that will initialize the trac database and also the sample configuration provided with each trac instance, providing sane initial defaults for use with both an existing environment and a newly created one. For the creation of a new environment it uses [source:trunk/trac/db_default.py the default db structure]. and on upgrade it will use [source:trunk/trac/upgrades a db upgrade path] defined in the individual db*.py modules therein. The version number of the trac database schema is available from the ''system'' table, the key to look for is ''database_version.'' The value of this system property will be updated on environment upgrade. In addition to that, trac will also keep track of the initial database version that was installed when first creating the environment. The key to look for in the ''system'' table is ''initial_database_version''.
    4848
     49
     50== Additional Information and References ==
     51
     52 * Preventing data corruption on upgrade[[br]]
     53   For the IEnvironmentSetupParticipant there is currently talk about a best practice to always commit changes to the database when upgrading using a migration path, so that on error during the migration, the existing data will not be corrupted. This basically involves atomic changes to the database, so that either all or none of the changes being applied will be committed. This also includes updating the system property ''database_version''.
     54
     55 * On upgrade the existing help pages in the wiki will not be updated[[br]]
     56   TBD link to existing issues[[br]]
     57   This is currently not being addressed by trac's default environment setup participant, as it is implemented in a different component. However, there is a proposed [wiki:TracDev/Proposals/NewHelp new help system] that would externalize all help pages to static resources in the filesystem.