Bulk Approval for tasks in SharePoint OOTB Workflow Task list

Hi All,

I am developing a SharePoint Add-In on SharePoint Online.

Background: Business requirements is that approvers should be able to perform bulk approval on the OOTB SharePoint Online Workflow Task list. I have developed a custom action called as Bulk approval where approvers can Approve or Reject leave request as shown below:




In the custom code, I have code the status to be Completed and Outcome to Approved if the Approves clicks on Approved button on bulk approval custom action using CSOM with following code:

var item = item[0];

Item.set_item(“Status”, “Completed”);
item.set_item(“Outcome”, “Approved”);
item.update();

Challenge:

Workflow Tasks has references to all the document libraries and custom list where workflow is attached. I have challenge to get all the document libraries, custom lists and loop the each document library, custom list  and set the Workflow status to Status, outcome depends on user action. There is related item column in the Workflow task as shown:




I made research and found some links:

CSOM: http://sharepoint.stackexchange.com/questions/88327/get-related-item-id-from-a-workflow-task-list

Sandy