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Since tasks have access to, and can modify, DSpace content, performing tasks is considered an administrative function to be available only to knowledgeable collection editors, repository administrators, sysadmins, etc. No tasks are exposed in the public interfaces.

Activation

Wiki MarkupFor CS to run a task, the code for the task must of course be included with other deployed code (to {{\[dspace\]/lib}}, WAR, etc) but it must also be declared and given a name. This is done via a configuration property in {{\[dspace\]/config/modules/curate.cfg}} as follows:

plugin.named.org.dspace.curate.CurationTask = \
org.dspace.ctask.general.NoOpCurationTask = noop, \
org.dspace.ctask.general.ProfileFormats = profileformats, \
org.dspace.ctask.general.RequiredMetadata = requiredmetadata, \
org.dspace.ctask.general.ClamScan = vscan, \
org.dspace.ctask.general.MicrosoftTranslator = translate, \
org.dspace.ctask.general.MetadataValueLinkChecker = checklinks

For each activated task, a key-value pair is added. The key is the fully qualified class name and the value is the taskname used elsewhere to configure the use of the task, as will be seen below. Note that the curate.cfg configuration file, while in the config directory, is located under 'modules'. The intent is that tasks, as well as any configuration they require, will be optional 'add-ons' to the basic system configuration. Adding or removing tasks has no impact on dspace.cfg.unmigrated-wiki-markup

For many tasks, this activation configuration is all that will be required to use it. But for others, the task needs specific configuration itself. A concrete example is described below, but note that these task-specific configuration property files also reside in {{\[dspace\]/config/modules}}

Writing your own tasks

A task is just a java class that can contain arbitrary code, but it must have 2 properties:

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1. From the 'Curate' tab that appears on each 'Edit Community/Collection/Item' page: this tab allows an Administrator, Community Administrator or Collection Administrator to run a Curation Task on that particular Community, Collection or Item. When running a task on a Community or Collection, that task will also execute on all its child objects, unless the Task itself states otherwise (e.g. running a task on a Collection will also run it across all Items within that Collection).
   • NOTE: Community Administrators and Collection Administrators can only run Curation Tasks on the Community or Collection which they administer, along with any child objects of that Community or Collection. For example, a Collection Administrator can run a task on that specific Collection, or on any of the Items within that Collection.
2. From the Administrator's 'Curation Tasks' page: This option is only available to DSpace Administrators, and appears in the Administrative side-menu. This page allows an Administrator to run a Curation Task across a single object, or all objects within the entire DSpace site.
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   • In order to run a task from this interface, you must enter in the handle for the DSpace object. To run a task site-wide, you can use the handle: {{\[your-handle-prefix\]/0}}

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Each of the above pages exposes a drop-down list of configured tasks, with a button to 'perform' the task, or queue it for later operation (see section below). Not all activated tasks need appear in the Curate tab - you filter them by means of a configuration property. This property also permits you to assign to the task a more user-friendly name than the PluginManager _taskname_. The property resides in {{\[dspace\]/config/modules/curate.cfg}}:

ui.tasknames = \
     profileformats = Profile Bitstream Formats, \
     requiredmetadata = Check for Required Metadata

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• a task can appear in more than one group if desired
• tasks that belong to no group are invisible to the admin UI (but of course available in other contexts of use)

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The configuration of groups follows the same simple pattern as tasks, using properties in {{\[dspace\]/config/modules/curate.cfg}}. The group is assigned a simple logical name, but also a localizable name that appears in the UI. For example

# ui.taskgroups contains the list of defined groups, together with a pretty name for UI display
ui.taskgroups = \
  replication = Backup and Restoration Tasks, \
  integrity = Metadata Integrity Tasks, \
  .....
# each group membership list is a separate property, whose value is comma-separated list of logical task names
ui.taskgroup.integrity = profileformats, requiredmetadata
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In workflow

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CS provides the ability to attach any number of tasks to standard DSpace workflows. Using a configuration file {{\[dspace\]/config/workflow-curation.xml}}, you can declaratively (without coding) wire tasks to any step in a workflow. An example:

Code Block
<taskset-map> <mapping collection-handle="default" taskset="cautious" /> </taskset-map> <tasksets> <taskset name="cautious"> <flowstep name="step1"> <task name="vscan"> <workflow>reject</workflow> <notify on="fail">$flowgroup</notify> <notify on="fail">$colladmin</notify> <notify on="error">$siteadmin</notify> </task> </flowstep> </taskset> </tasksets>

This markup would cause a virus scan to occur during step one of workflow for any collection, and automatically reject any submissions with infected files. It would further notify (via email) both the reviewers (step 1 group), and the collection administrators, if either of these are defined. If it could not perform the scan, the site administrator would be notified.

Wiki MarkupThe notifications use the same procedures that other workflow notifications do - namely email. There is a new email template defined for curation task use: {{\[dspace\]/config/emails/flowtask_notify}}. This may be language-localized or otherwise modified like any other email template.

Tasks wired in this way are normally performed as soon as the workflow step is entered, and the outcome action (defined by the 'workflow' element) immediately follows. It is also possible to delay the performance of the task - which will ensure a responsive system - by queuing the task instead of directly performing it:

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Code Block
Curator curator = new Curator(); curator.addTask("vscan").curate(coll); int status = curator.getStatus("vscan"); String result - curator.getResult("vscan");

Task Properties

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DSpace 1.8 introduces a new 'idiom' for tasks that require configuration data. It is available to any task whose implementation extends _AbstractCurationTask_, but is completely optional. There are a number of problems that task properties are designed to solve, but to make the discussion concrete we will start with a particular one: the problem of hard-coded configuration file names. A task that relies on configuration data will typically encode a fixed reference to a configuration file name. For example, the virus scan task reads a file called 'clamav.cfg', which lives in {{\[dspace\]/config/modules}}. And thus in the implementation one would find:

Code Block
host = ConfigurationManager.getProperty("clamav", "service.host");

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Code Block
org.dspace.ctask.general.ClamAv = vscan, org.community.ctask.ConflictTask = virusscan, ....

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then 'taskProperty()' will resolve to {{\[dspace\]/config/modules/vscan.cfg}} when called from ClamAv task, but {{\[dspace\]/config/modules/virusscan.cfg}} when called from ConflictTask's code. Note that the 'vscan' etc are locally assigned names, so we can always prevent the 'collisions'mentioned, and we make the tasks much more portable, since we remove the 'hard-coding' of config names.

The entire 'API' for task properties is:

Code Block
public String taskProperty(String name); public int taskIntProperty(String name, int defaultValue); public long taskLongProperty(String name, long defaultValue); public boolean taskBooleanProperty(String name, boolean default);

Wiki MarkupAnother use of task properties is to support multiple task profiles. Suppose we have a task that we want to operate in one of two modes. A good example would be a mediafilter task that produces a thumbnail. We can either create one if it doesn't exist, or run with '-force' which will create one regardless. Suppose this behavior was controlled by a property in a config file. If we configured the task as 'thumbnail', then we would have in {{\[dspace\]/config/modules/thumbnail.cfg}}:

Code Block
...other properties... thumbnail.maxheight = 80 thumbnail.maxwidth = 80 forceupdate=false

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DSpace 1.8 includes limited (and somewhat experimental) support for deploying and running tasks written in languages other than Java. Since version 6, Java has provided a standard way (API) to invoke so-called scripting or dynamic language code that runs on the java virtual machine (JVM). Scripted tasks are those written in a language accessible from this API. The exact number of supported languages will vary over time, and the degree of maturity of each language, or suitability of the language for curation tasks will also vary significantly. However, preliminary work indicates that Ruby (using the JRuby runtime) and Groovy may prove viable task languages.

Wiki MarkupSupport for scripted tasks does *not* include any DSpace pre-installation of the scripting language itself - this must be done according to the instructions provided by the language maintainers, and typically only requires a few additional jars on the DSpace classpath. Once one or more languages have been installed into the DSpace deployment, task support is fairly straightforward. One new property must be defined in {{\[dspace\]/config/modules/curate.cfg}}:

Code Block
script.dir = ${dspace.dir}/scripts

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This plugin requires a ClamAV daemon installed and configured for TCP sockets. Instructions for installing ClamAV (http://www.clamav.net/doc/latest/clamdoc.pdf )

NOTICE: The following directions assume there is a properly installed and configured clamav daemon. Refer to links above for more information about ClamAV.
The Clam anti-virus database must be updated regularly to maintain the most current level of anti-virus protection. Please refer to the ClamAV documentation for instructions about maintaining the anti-virus database.

DSpace Configuration

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In {{\[dspace\]/config/modules/curate.cfg}}, activate the task:

• Add the plugin to the comma separated list of curation tasks.

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Code Block
ui.tasknames = \ profileformats = Profile Bitstream Formats, \ requiredmetadata = Check for Required Metadata, \ vscan = Scan for Viruses

• Wiki MarkupIn {{\[dspace\]/config/modules}}, edit configuration file clamav.cfg:

Code Block
service.host = 127.0.0.1 Change if not running on the same host as your DSpace installation. service.port = 3310 Change if not using standard ClamAV port socket.timeout = 120 Change if longer timeout needed scan.failfast = false Change only if items have large numbers of bitstreams

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• Finally, if desired virus scanning can be enabled as part of the submission process upload file step. In {{\[dspace\]/config/modules}}, edit configuration file {{submission-curation.cfg}}:

Code Block
virus-scan = true

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Task Operation from the Item Submission user interface

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If desired virus scanning can be enabled as part of the submission process upload file step. In {{\[dspace\]/config/modules}}, edit configuration file {{submission-curation.cfg}}:

Code Block
virus-scan = true

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Configure Microsoft Translator

Wiki MarkupAn example configuration file can be found in \ [dspace\]/config/modules/translator.cfg.

#---------------------------------------------------------------#
#----------TRANSLATOR CURATION TASK CONFIGURATIONS--------------#
#---------------------------------------------------------------#
# Configuration properties used solely by MicrosoftTranslator   #
# Curation Task (uses Microsoft Translation API v2)             #
#---------------------------------------------------------------#
## Translation field settings
##
## Authoritative language field
## This will be read to determine the original language an item was submitted in
## Default: dc.language

translate.field.language = dc.language

## Metadata fields you wish to have translated
#
translate.field.targets = dc.description.abstract, dc.title, dc.type

## Translation language settings
##
## If the language field configured in translate.field.language is not present
## in the record, set translate.language.default to a default source language
## or leave blank to use autodetection
#
translate.language.default = en

## Target languages for translation
#
translate.language.targets = de, fr

## Translation API settings
##
## Your Bing API v2 key and/or Google "Simple API Access" Key
## (note to Google users: your v1 API key will not work with Translate v2,
## you will need to visit https://code.google.com/apis/console and activate
## a Simple API Access key)
##
## You do not need to enter a key for both services.
#
translate.api.key.microsoft = YOUR_MICROSOFT_API_KEY_GOES_HERE
translate.api.key.google = YOUR_GOOGLE_API_KEY_GOES_HERE