The purpose of the Document Task Manager (DTM) is to perform a certain task across a set of documents. The DTM is an optional component running inside the Daisy Repository Server. Some of its features are:

Tasks are executed in the background, inside the repository server. Thus the user (a person or another application) starting the task does not have to wait until it is completed, but can do something else and check later if the task ended successfully.

The execution progress of the task is maintained persistently in the database. For each document on which the task needs to be executed, you can consult whether it has been performed successfully, whether it failed (and why), or whether it still has to be executed. Since this information is tracked persistently in the database, it is not lost in case the server would be interrupted.

Tasks can be interrupted. Since the task is performed on one document after another, it is easily possible to interrupt between two documents.

Tasks can be written in Javascript or be composed from built-in actions. Executing custom Javascript-based tasks is only allowed by Administrators, since there is a certain risk associated with it. For example, it is possible to write a task containing an endless loop which would only be interruptible by shutting down the repository server, or a task could call System.exit() to shut down the server.

The execution details of a task, which are stored in the database, are cleaned up automatically after two weeks (by default), and can of course also be deleted manually.

The DTM is accessible via the HTTP API and the Java API.

The Daisy Wiki contains a frontend for starting new tasks and consulting the execution details of existing tasks.

Ideas for the future:

• scheduled execution of document tasks
• adding more built-in actions (the ones currently available are mainly to support working with document variants)