Taskflow Backend

The taskflowbackend backend app is an optional add-on used if your site setup contains the separate SODAR Taskflow data transaction service.

If you have not set up a SODAR Taskflow service for any purpose, this backend is not needed and can be ignored.

Basics

The taskflowbackend backend app is used in the main SODAR site to communicate with an external SODAR Taskflow service to manage large-scale data transactions. It has no views or database models and only provides an API for other apps to use.

Note

At the time of writing, SODAR Taskflow is in development and has not been made public.

Installation

Warning

To install this app you must have the django-sodar-core package installed and the projectroles app integrated into your Django site. See the projectroles integration document for instructions.

Django Settings

The taskflowbackend app is available for your Django site after installing django-sodar-core. Add the app into THIRD_PARTY_APPS as follows:

THIRD_PARTY_APPS = [
    # ...
    'taskflowbackend.apps.TaskflowbackendConfig',
]

Next add the backend to the list of enabled backend plugins:

ENABLED_BACKEND_PLUGINS = env.list('ENABLED_BACKEND_PLUGINS', None, [
    # ...
    'taskflow',
])

The following app settings must be included in order to use the backend. Note that the values for TASKFLOW_TARGETS depend on your SODAR Taskflow configuration.

# Taskflow backend settings
TASKFLOW_BACKEND_HOST = env.str('TASKFLOW_BACKEND_HOST', 'http://0.0.0.0')
TASKFLOW_BACKEND_PORT = env.int('TASKFLOW_BACKEND_PORT', 5005)
TASKFLOW_SODAR_SECRET = env.str('TASKFLOW_SODAR_SECRET', 'CHANGE ME!')
TASKFLOW_TARGETS = [
    'sodar',
    # ..
]

Register Plugin

To register the taskflowbackend plugin, run the following management command:

$ ./manage.py syncplugins

You should see the following output:

Registering Plugin for taskflowbackend.plugins.BackendPlugin

Usage

Once enabled, Retrieve the backend API class with the following in your Django app python code:

from projectroles.plugins import get_backend_api
taskflow = get_backend_api('taskflow')

See the docstrings of the API for more details.

To initiate sync of existing data with your SODAR Taskflow service, you can use the following management command:

./manage.py synctaskflow

API Documentation

The TaskflowAPI class contains the SODAR Taskflow backend API. It should be initialized using the Projectroles.plugins.get_backend_api() function.

class taskflowbackend.api.TaskflowAPI

SODAR Taskflow API to be used by Django apps

exception CleanupException

SODAR Taskflow cleanup exception

exception FlowSubmitException

SODAR Taskflow submission exception

cleanup()

Send a cleanup command to SODAR Taskflow. Only allowed in test mode.

Returns

Boolean

Raise

ImproperlyConfigured if TASKFLOW_TEST_MODE is not set True

Raise

CleanupException if SODAR Taskflow raises an error

get_error_msg(flow_name, submit_info)

Return a printable version of a SODAR Taskflow error message.

Parameters

• flow_name – Name of submitted flow

• submit_info – Returned information from SODAR Taskflow

Returns

String

submit(project_uuid, flow_name, flow_data, request=None, targets=['sodar'], request_mode='sync', timeline_uuid=None, force_fail=False, sodar_url=None)

Submit taskflow for SODAR project data modification.

Parameters

• project_uuid – UUID of the project (UUID object or string)

• flow_name – Name of flow to be executed (string)

• flow_data – Input data for flow execution (dict)

• request – Request object (optional)

• targets – Names of backends to sync with (list)

• request_mode – “sync” or “async”

• timeline_uuid – UUID of corresponding timeline event (optional)

• force_fail – Make flow fail on purpose (boolean, default False)

• sodar_url – URL of SODAR server (optional, for testing)

Returns

Boolean

Raise

FlowSubmitException if submission fails

use_taskflow(project)

Check whether taskflow use is allowed with a project.

Parameters

project – Project object

Returns

Boolean