Task nodes have several parts and are the most complex parts of a workflow definition. Unlike other workflow nodes, task nodes have Assignments, because a User is expected to do something (often approve or reject the submitted asset) when a workflow process enters the task node: the assignment specifies who that User is.
Commonly, task nodes contain Notifications, Assignments, and Actions (defined in scripts). See more about Notifications and Actions in the article on workflow nodes. Task nodes and their assignments are more complex and deserve their own article (this one).
To get started, drag and drop a task node on your workflow canvas if you haven’t already. Open its Properties and give it a name. Then double click Actions in the task’s Properties pane.
You can define a notification (often Task Assignee is appropriate), or write a Groovy script defining an action that’s triggered for your task.
Next learn about creating Assignments for your task nodes.
Assignments
Workflow tasks must be completed by a User. You can choose how you want to configure your assignments.
Figure 1: You can add an Assignment to a Task node.
You can choose to add assignments to specific Roles, multiple Roles of a Role Type (Organization, Site, or regular Role types), to the Asset Creator, to Resource Actions, or to specific Users. Additionally, you can write a script to define the assignment.
Assigning tasks to Roles, Organizations, or Asset Creators is a straightforward concept, but what does it mean to assign a workflow task to a Resource Action? Imagine an UPDATE resource action. If your workflow definition specifies the UPDATE action in an assignment, anyone who has permission to update the type of asset being processed in the workflow is assigned to the task. You can configure multiple assignments for a task.
Resource Action Assignments
Resource actions are operations performed by Users on an application or entity. For example, a User might have permission to update Message Boards Messages. This is called an UPDATE resource action, because the User can update the resource. If you’re still uncertain about what resource actions are, refer to the developer tutorial on the permission system for a more detailed explanation.
To find all the resource actions that have been configured, you need access to the Roles Admin application in the Control Panel (in other words, you need permission for the VIEW action on the Roles resource).
- Navigate to Control Panel → Users → Roles.
- Add a new Regular Role. See the article on managing roles for more information.
- Once the Role is added, navigate to the Define Permissions interface for the Role.
- Find the resource whose action you want to use for defining your workflow assignment.
How do you go from finding the resource action to using it in the workflow? Use the Workflow Designer’s interface for setting up a resource action assignment.
When configuring your task node’s Assignment, select Resource Actions as the Assignment Type, then specify the Resource Actions to use for the assignment (for example, UPDATE).
Figure 2: Configure resource action assignments in the Workflow Designer.
Here’s what the assignment looks like in the Source (Workflow XML) tab:
<assignments>
<resource-actions>
<resource-action>UPDATE</resource-action>
</resource-actions>
</assignments>
As usual, assign the workflow to the appropriate workflow enabled asset.
Now when the workflow proceeds to the task with the resource action assignment,
Users with UPDATE permission on the resource (for example, Message Boards
Messages) are notified of the task and can assign it to themselves (if the
notification is set to Task Assignees). Specifically, Users see the tasks in
their My Workflow Tasks application under the tab Assigned to My Roles.
Use all upper case letters for resource action names. Here are some common resource actions:
UPDATE
ADD
DELETE
VIEW
PERMISSIONS
SUBSCRIBE
ADD_DISCUSSION
You can determine the probable resource action name from the permissions screen for that resource. For example, in Message Boards, one of the permissions displayed on that screen is Add Discussion. Convert that to all uppercase and replace the space with an underscore, and you have the action name.
Scripted Assignments
You can also use a script to manage the assignment. Here’s the script for the
Review task assignment in the Scripted Single Approver workflow definition
(single-approver-definition-scripted-assignment.xml):
import com.liferay.portal.kernel.model.Group;
import com.liferay.portal.kernel.model.Role;
import com.liferay.portal.kernel.service.GroupLocalServiceUtil;
import com.liferay.portal.kernel.service.RoleLocalServiceUtil;
import com.liferay.portal.kernel.util.GetterUtil;
import com.liferay.portal.kernel.workflow.WorkflowConstants;
long companyId = GetterUtil.getLong((String)workflowContext.get(WorkflowConstants.CONTEXT_COMPANY_ID));
long groupId = GetterUtil.getLong((String)workflowContext.get(WorkflowConstants.CONTEXT_GROUP_ID));
Group group = GroupLocalServiceUtil.getGroup(groupId);
roles = new ArrayList<Role>();
Role adminRole = RoleLocalServiceUtil.getRole(companyId, "Administrator");
roles.add(adminRole);
if (group.isOrganization()) {
Role role = RoleLocalServiceUtil.getRole(companyId, "Organization Content Reviewer");
roles.add(role);
}
else {
Role role = RoleLocalServiceUtil.getRole(companyId, "Site Content Reviewer");
roles.add(role);
}
user = null;
Don’t let all that code intimidate you. It’s just assigning the task to the Administrator Role, then checking whether the group of the asset is an Organization and assigning it to the Organization Content Reviewer Role if it is. If it’s not, it’s assigning the task to the Site Content Reviewer Role.
Note the roles = new ArrayList<Role>(); line above. In a scripted assignment,
the roles variable is where you specify any Roles the task is assigned to. For
example, when roles.add(adminRole); is called, the Administrator role is added
to the assignment.