Implementing a user self-registration scenario using Workflow and Business rules in SAP Cloud Platform – Part 5

UPDATE [13/8/2017]: Calling an external service from a Custom UI Task

In this portion of the blog series, I will show you how to create a custom HTML5 app which is the Start UI for triggering the workflow. I have uploaded the project in github for your reference.

SAP Cloud Platform workflow service provides REST APIs which can be used by applications to interact with the service. In this section, we are going to leverage workflow-instance REST API to create a new instance.

You can navigate to a particular API to read the documentation and also find sample payload. In the below image, I have highlighted two important things – Workflow definition ID and context. This needs to be provided when triggering a workflow.

In the Start UI, I have created a XML view which will display the user registration form. I have put the usual fields like firstname, lastname, email, phone etc.

In the controller definition, I am invoking two REST APIs. The first one is to get X-CSRF-Token and the subsequent call is to make a POST call with the X-CSRF-Token along with the context payload. The context payload would contain the information provided by the user in the registration form

You can find the compete source code here at github.

I have deployed this App to my SAP Cloud Platform cockpit. When I run this app, I get the below screen where I can provide user information and click on submit. Notice that I have provided an email with domain “vendorA”. The business rules within the workflow should find the relevant approver and default IdP group for this vendor organization.

After submitting, this request, a task gets created and I can view the task instance using the REST APIs.  In the below screenshot, the tasks is currently sitting in My Inbox for the recipient to action. Notice that the business rules have already been applied. You can say that by the output node which is populated with the approver and default IdP group.

When I logon to My Inbox, I would be able to see this task waiting for me to action. Notice that the default IdP group has been picked up and is also displayed on the screen.

As an approver, I can decide to approve this task by clicking on “Approve” button. This will invoke the SCIM APIs exposed from SAP Cloud Platform Identity Authentication service. I have defined a method called createSCIUser which prepares the input and makes an ajax call.

When calling an external service from the Custom UI task the URL needs to be proerply formatted as explain in the Help documentation. In the example above, the URL to invoke a SCIM API would be URL: /html5apps/mywfapp/SCI/. I have created a destination in my SAP CP cockpit with the name SCI which refers to my SCI tenant.

If you would like to know more about how to invoke the SCIM APIs, you can check the SAP Help documentation.

After approving the task, when I navigate to the Cloud Identity, I will be able to see the user created.

Secondly, when I navigate to the “User Groups” menu and explore the “AccountsPayable_A” group, I would be able to see the newly created user assigned to this group.

In the next part of the blog, I will show you how to setup trust between SAP Cloud Platform Identity Authentication service and Cloud Portal.