Workshop: Build the Expense Application

This tutorial covers the development of a siple expense reimbursement application using Flows for APEX.

Aims of the Tutorial:

After completing this workshop, you should be able to:

  • Navigate around the Flows for APEX Application, using the Flow Modeler and the Flow Monitor
  • Use the Flow Modeler to
    • Design, save, and test-run a business proces diagram.
    • Edit the process model to add new activities and lanes
    • Add detail to the process model until becomes an executable model
    • Configure a BPMN User Task as an APEX Page Task or an APEX Human Task
    • Configure a BPMN Script Task to run a PL/SQL script
    • Configure a BPMN Service Task to send email using APEX Mail
    • Configure Exclusive, Inclusive, and Parallel Gateways
  • Use the Flow Monitor to:
    • Create and Start a Process Instance from the Monitor
    • Step a Process Forward
    • Examine (and change) Process Variables
  • Create an APEX App to implement a simple workflow
    • Prepare the App by Copying in the Flows for APEX Component Group
    • Create and Configure an APEX Task List for Flows for APEX
    • Implement a User Task as an APEX Page, adding Plugin Processes
    • Implement a User Task using an APEX Human Task for an approval
    • Adding a Flow Viewer to your app

Stage 1: Using the Flows for APEX Application.

Stage 2: Modeling a Simple Process

We’re going to build a simple workflow for approving and processing an expense report.

Here’s the process model that we will end up with.

Expense Application Model

Note that the process starts with an expense report - the first step is NOT creating the expense report.

Code Snippets

For Script Task

declare
    l_process_id        number := flow_globals.process_id;
    l_expense_id        expense_report.id%type;
    l_employee_username expense_report.employee_username%type;
    l_category          expense_report.category%type;
    l_amount            expense_report.amount%type;
begin
    -- get business reference from workflow instance
    l_expense_id := flow_process_vars.get_business_ref(pi_prcs_id => l_process_id);

    --update expense status
    update expense_report
       set status = 'APPROVED'
     where id =  l_expense_id
     returning employee_username, category, amount
     into l_employee_username, l_category, l_amount;

     -- insert a payment request 
    insert into payment_request
    (employee_username, category, amount)
    values 
    (l_employee_username, l_category, l_amount);
end;

For Approved? Gateway - forward paths

:F4A$APPROVAL_OUTCOME = 'APPROVED'

:F4A$APPROVAL_OUTCOME = 'REJECTED'

For Send Email Service Task

Create 4 Variable Expressions that execute BEFORE TASK

EMAIL:

select employee_username
  from expense_report
 where id = :F4A$BUSINESS_REF

AMOUNT:

select amount
  from expense_report
 where id = :F4A$BUSINESS_REF

EXPENSE_DATE

select to_char(expense_date, 'DD/MM/YYYY')
  from expense_report
 where id = :F4A$BUSINESS_REF

CATEGORY

select category
  from expense_report
 where id = :F4A$BUSINESS_REF