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Most processes depict real-life, practical business or scientific scenarios which need the interactions of a human at least once in its workflow design. Typically, these interactions are initiated by the process itself, and requests a user input to proceed. For example, consider a "bank loan request" process which often requires the final decision to be taken by a human.

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1. Log on to the product's management console and select "Human Tasks-> Add" under the "Main" menu.
    
2. The "New HumanTask Package" window opens. Provide the file and click "Upload.
   
3. The "Deployed Task Configurations" window opens with the newly-added human task listed. For example,
   
   • Package Name:    The name of the package.
   • Task Definition:   The task definition
   • Type: Whether this definition is a Task or a Notification 
   • Status: The package status.
4. Click on a selected "Task Definition".
   

Writing a human task artifact

Human tasks

Business processes cannot always proceed in a fully automated manner. They need human interaction as a means of decision making, error handling and exception cases. For example, canceling a flight due to a strike or bankruptcy, deciding whether to accept the claim based on the requested amount etc. Human tasks provide the specification to define tasks performed by human beings.

Sample Scenario

When a user requests a claim to be approved by the system, the system automatically approves claims under an amount of 1000 .This is a simple BPEL process. If the claim exceeds 1000, it will be handed over to the regional clerk who checks the claim amount along with the user information, decides whether or not to approve it, and the final decision is sent to the user. So when the claim is higher than 1000, it will be processed as a human task. The sample process is shown below.

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Writing human tasks

The basic process is designed as a normal BPEL process with an IF component. For human tasks, we use the BPEL4PEOPLE activity remote task. It will get the input from the claim approval request such as the name and amount, and the output is sent via a claim approval callback service as true or false. The user can then see the final decision. This process needs some presentation elements. Human tasks are implemented as jsp pages.

The BPEL process is implemented using the BPEL4PEOPLE activities and deployed into the server. Human tasks have to be deployed as a separate process. Since there is no tool to create a human task workflow, all the steps have to be done manually. However, there is a predefined package structure which makes the work easier. As an initial step, you should create a package structure in your local directory.

Package structure of an HT artifact

There are four components in the HT package.

.ht file

The .ht file contains the information about the human task of the BPEL process. It is an xml based file consisting of a predefined set of human task description elements. The table below shows the basic elements and their descriptions with some examples from the ClaimsApprovalTask sample.

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<htd:humanInteractions>

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<htd:import>

...

Used to import appropriate wsdl files. You should correctly specify the name spaces.

Example:

<htd:importnamespace="http://reminder.sample.humantask.wso2.org"location="OrderProcessReminder.wsdl"importType="http://schemas.xmlsoap.org/wsdl/">

...

<htd:logicalPeopleGroups>

...

Used to specify logical people groups used in an inline human task or a people activity. The name attribute contains the name of the logical people group. The name must be unique among the names of all logical people groups defined within the <htd:human Interactions> element.  

<htd:logicalPeopleGroups>   
<htd:logicalPeopleGroupname="regionalClerks">  
<htd:documentationxml:lang="en-US"> 

 The group of clerks responsible for the region specified.  

</htd:documentation>fd   
<htd:parametername="role" type="xsd:string"/>  
</htd:logicalPeopleGroup>

...

<htd:tasks>

...

Specifies the human tasks used in the business process.

<htd:tasks>
        <htd:task1>
        <htd:task2>
        <htd:task3>
<htd:tasks>

...

<htd:task> 

...

Used to provide the definition of an inline human task. The name attribute specifies the name of the task. The name must be unique among the names of all tasks defined within the <htd:tasks> element.

It also consists of the <htd:interface>, <htd:peopleAssignments> and <htd:presentationElements> elements which are used to described the task.

<htd:task name="OrderProcess">  
<htd:interface/>
<htd:peopleAssignments/>
<htd:presentationElements/>
</htd:task>

...

<htd:interface>

...

Specifies the port types and operations of the human task.     

<htd:interface 
 portType="cl:ClaimsHandlingPT"  
  operation="approve"   
 responsePortType="cl:ClaimsHandlingCallbackPT"   
  responseOperation="approvalResponse"/>  

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<htd:peopleAssignments>

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Used to assign people to process-related generic human roles.
 

<<htd:peopleAssignments>
                <htd:potentialOwners>
                    <htd:from logicalPeopleGroup="regionalClerks">
                        <htd:argument name="role">
                            regionalClerksRole
                        </htd:argument>
                    </htd:from>
                </htd:potentialOwners>
                <htd:businessAdministrators>
                    <htd:from logicalPeopleGroup="regionalManager">
                        <htd:argument name="role">
                            regionalManagerRole
                        </htd:argument>
                    </htd:from>
                </htd:businessAdministrators>
            </htd:peopleAssignments>

...

<htd:documentation> 

...

Provides annotations for users.

<htd:documentation>  

Example for WS-HumanTask 1.1 - WS-HumanTask Task Definition  

</htd:documentation>  

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<htd:from>
<htd:argument> 

...

From element used to assign people for roles which have been specified in the business process. Argument element will pass values used in the people query.

 <htd:from logicalPeopleGroup="regionalClerks">
                        <htd:argument name="role">
                            regionalClerksRole
                        </htd:argument>
                    </htd:from>

...

<htd:presentationElements>

...

Specifies the user interface for human tasks or how the user interacts with the human task.

<htd:presentationElements>   
<htd:name xml:lang="en-US">Approve Claim
</htd:name>  
<htd:name xml:lang="de-DE">Genehmigungder Schadensforderung  
</htd:name>   
<htd:presentationParameters>   
<htd:presentationParametername="firstname"  
  type="xsd:string">   
 htd:getInput("ClaimApprovalRequest")/test10:cust/test10:firstname   
</htd:presentationParameter>   
</htd:presentationParameters>

...

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<htd:notifications>

...

Used to provide the definition of an inline notification.The name attribute specifies the name of the notification. The name must be unique among the names of all notifications defined within the <htd:notifications> element.

<htd:notifications>   
  <htd:notificationname="ClaimApprovalReminder">  
  <htd:documentationxml:lang="en-US">

htconfig.xml file

This file consists of deployment details of the human task. Human tasks supports two task types called task and notification. A task can have a publish and a callback. Publish means providing a service and Callback means calling an external service to provide the output. Notification is also a task type. A notification task provides one operation for external parties to create notifications. 

Example from the claim task sample:

<hic:HTDeploymentConfig xmlns:hic="http://wso2.org/ht/schema/deployment/config"
	xmlns:claim="http://www.example.com/claims/"
	xmlns:claimtask="http://www.example.com">
	<hic:task name="claimtask:ApproveClaim">
		<hic:publish>
			<hic:service name="claim:ClaimService" port="ClaimPort" />
		</hic:publish>
		<hic:callback>
			<hic:service name="claim:ClaimServiceCB" port="ClaimPortCB" />
		</hic:callback>
	</hic:task>
	<hic:notification name="claimtask:ClaimApprovalReminder">
		<hic:publish>
			<hic:service name="claim:ClaimReminderService" port="ClaimReminderPort" />
		</hic:publish>
	</hic:notification>
</hic:HTDeploymentConfig>

Here, the htconfig.xml file consists of three services used by a human task; get data from the user, call back of either approve or not and the reminder web service.

<Service>.wsdl

You can have one or more WSDL files which have been used in the BPEL process. You can have a composite WSDL addressing many web services. Claim Approval task has one composite WSDL.

Web folder

There are four jsp files inside the web folder. Three jsp files end with:

1. <TaskName>-input.jsp 
2. <TaskName>-output.jsp
3. <TaskName>-response.jsp

<TaskName>-input.jsp

The input.jsp file uses (OMElement) request.getAttribute("taskInput") attribute to obtain the task Details OMElement. This is inserted into the JSP context from BPS. The input.jsp file is used to show the task information to the task user.

Example from the ApproveClaim-input.jsp:

OMElement requestElement = (OMElement) request.getAttribute("taskInput");
	String ns = "http://www.example.com/claims/schema";
	if (requestElement != null) {
	OMElement customerElement = requestElement.getFirstChildWithName(new QName(ns, "cust"));
	if (customerElement != null) {
OMElement id = customerElement.getFirstChildWithName(new QName(ns, "id"));
if (id != null) {
customerId = id.getText();
}

The input web will show the human task list of the regional clerk user.

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<TaskName>-output.jsp

The output .jsp is used to provide the user with a task form. Task processing happens when this is completed and submitted by the user.

All output .jsp files should implement the JavaScript method:

createTaskOutput = function() { 
};

which should output the corresponding xml string expected by the task operation.

Example from the ApproveClaim-output.jsp:

createTaskOutput = function() {
var outputVal = getCheckedRadio(); //get approve or not from radio button
if(outputVal == 'approve') {return'<sch:ClaimApprovalResponse 	xmlns:sch="http://www.example.com/claims/schema"><sch:approved>true</sch:approved></sch:ClaimApprova	lResponse>';
} else if (outputVal == 'disapprove') {return'<sch:ClaimApprovalResponse 	  
xmlns:sch= "http://www.example.com/claims/schema"> <sch:approved>false</sch:approved>
</sch:ClaimApprov	 alResponse>';
}
};

Output JSP will be used by the regional clerk user to approve the claim.

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<TaskName>-response.jsp

Response.jsp is used to display the output of the completed task. It also uses the OMElement responseElement = (OMElement) request.getAttribute("taskOutput"); to obtain the OMElement corresponding to the output.

Example from the ApproveClaim-response.jsp:

String approved = "No Value Assigned"; 
OMElement responseElement = (OMElement) request.getAttribute("taskOutput"); 
if (responseElement != null) { 
approved = responseElement.getFirstElement().getText(); }

The response after approving the claim looks like this:

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