Flows for APEX v5.0

During the ODTUG Learn From Home Series in May 2020, I announced the general availability of the open source tool Flows for APEX. Flows for APEX lets you model and run process flows in low-code style. It comes as a packaged app, so you just have to import the app and you are good to go. Also, it follows the BPMN 2.0 standard, so you could easily reuse the created flows with BPMN products like Camunda if needed.

Since I received many questions about it, I would like to give developers some insight in how to work with it. The most important thing to know is that it was designed to let APEX developers drive the flow by custom PL/SQL, not the other way around. You, as a programmer, decide when a certain step in a flow is achieved by calling the appropriate API. Let us go through a simple example. Let's say, somebody needs to be over 18 years old to get an insurance policy after submitting a form. With Flows for APEX, you would first model this flow (normally you would let the business department do this for you). The outcome may look like this:

Upon saving the flow, the XML that came out of the JS library called bpmn.io is stored as a CLOB in the table flow_diagrams. All parts of the flow are stored in table flow_objects and all connections, guess what, in flow_connections. You, as an APEX developer, can now start creating your app, thereby creating a form based on your own table, lets say forms. To display the flow in your app, reuse the plugin "BPMN viewer" from the Flows for APEX app. Lastly, you need to start the flow and instruct when it has to move one step further. You do this by calling the PL/SQL API of Flows for APEX, ideally from within your own business package. For example, after approving the submitted application form, you would call a procedure in this package called form_approve that calls the appropriate API of Flows for APEX. Of course, since we are in PL/SQL context, you could do here whatever you want: logging, calling a web service, send an e-mail, etc. Each step in the flow can have its own procedure, but this mainly depends on what you are trying to accomplish.

A basic example of a package procedure that is called from APEX could look like this:

 

procedure form_approve

( pi_process_id in number

, pi_subflow_id in number

)

is

begin

  -- set process variable for gateway

  -- pi_var_name  => the ID of the gateway as specified during modelling

  -- pi_vc2_value => the ID of the connection where the gateway should route to

  flow_process_vars.set_var

  ( pi_prcs_id   => pi_process_id

  , pi_var_name  => 'Gateway_over18'

  , pi_vc2_value => 'Connection_yes'

);

  -- move one step further

  -- the engine will automatically route to the next task

  flow_api_pkg.flow_complete_step

  ( p_process_id  => pi_process_id

  , p_subflow_id  => pi_subflow_id

  );

end;

I recommend starting off by installing the demo packaged app Order Shipment that comes with Flows for APEX v5.

To learn more about BPMN 2.0, see our example process flows at https://bit.ly/flowsforapex.

Looking forward to hear about your experiences!


Resources for APEX developers:

Download Flows for APEX: https://apex.mt-ag.com/flowsforapex
Play with it on apex.oracle.com: https://bit.ly/flowsforapex

See a custom demo app on apex.oracle.com: https://bit.ly/flowsforapexdemo
Presentation slides: https://knowledgebase.mt-ag.com/q/flowsforapex

Introduction video: https://www.youtube.com/watch?v=lMDMVXPy0Jk&list=PL3S33P01ea06WdgNtuFvGd-f8PvP54-g0

Resources for Flows for APEX contributors:
Github: https://github.com/mt-ag/apex-flowsforapex