Question

Is there any OOTB feature available in appian to update the pv variables of the inflight instances apart from IFM (In-flight Modification) plugin? please suggest.

Forum|Forum|2 years ago
July 4, 2024
16 replies
0 views

Is there any OOTB feature available in appian to programmatically update the pv variables of the inflight instances like any smart service, apart from IFM (In-flight Modification) plugin? please suggest.

stefanhelzle0001

Brainy

That is the only way. What are you looking for?

rajarajeswarib0001Author

I basically want to update a pv variable for a list of inflight instances.

davidj137213

Brainy

Did you check this?

Changing process variables

It's possible to change the value of process variables in a process instance. The approach differs based on the type of the variable.

To change process variables of system data types:

From the toolbar, select the Process Model Properties icon to view the process variables.
Select a process variable to update it.
For a process variable of type multiple, insert the value with a comma separator. For example, to add an array of two values to a process variable of type Text, enter text string 1, text string 2.

To change process variables of custom data types, you need to add a script task to your process model that stores the new value into the variable:

Edit the process.
Drag and drop a script task onto the canvas.
Add a node input, and choose the custom data type as its type.
Set the new values.
Save the node input into the process variable that you want to update.
Apply your changes to the process instance.
Switch to Monitor mode.
Close the tab open in Edit mode.
Right-click on the new script task and select Start.

To change an encrypted text value, you can use a technique similar to modifying values of custom data types:

Edit the process.
Drag and drop a User Input task onto the canvas.
Add a node input of type Encrypted Text.
Configure an interface that displays the encrypted text value and saves the updated value back into the node input.
Save the node input into the process variable that you want to update.
Apply your changes to the process instance.
Switch to Monitor mode.
Close the tab open in Edit mode.
Right-click on the new User Input task and select Start

docs.appian.com/.../Monitoring_and_Editing_Processes.html

csteward

There are a few ways you can achieve this type of design, if needed. I've used similar setups in situations such as, process data can be updated outside of the regular flow / Related Action while the process is active, and the main process CDTs need to obtain the updates as well.

To note, I have used the IFM Manager in a single one-off support situation, it worked but I would not recommend building this into your design, reserving it for unforeseen support situations only.

Typically I will have the Related Action / outside flow update the database for the main process instance (query data, update, persist back to DB), then make a call to the process instance(s) with one of a few methods to update it's own CDTs, such as with process messaging. This works if your variables are always persisted to the DB. The model is setup something like below:

When the process starts, the Main Flow moves on while the Update flow waits at a Receive Message node. Once the outside process is complete it will message the main process, which starts the Reset node that queries data back from the DB via a!queryEntity(), updates it's own CDTs, and returns to the Receive Message node to wait for further updates. This is my preferred method since it is all OOTB, but you should review the Process Messaging Best Practices to determine if it is acceptable for your case.

There are race conditions to be aware of as well, depending on your process you may consider pessimistic locking. E.g. if an outside update is occurring at the same time your main process is being updated.

Alternatively I'll note some related plugins:

- Process Management Services is one I've used in a similar setup as above, where instead of messaging we use the Start All Nodes service to call the main process to update it's own data from the DB.

- Get and Set External Process Variables is an older plugin that can Set External PVs, you can send the data directly to the process variables without needing them persisted to the DB.

Always with plugins, you run some risk of issues after upgrades, etc. My preferred method is always whatever is OOTB.

mathieud0001

Brainy

I've started using a similar approach recently.Though instead of resetting the PVs from the DB, I simply pass in a map of PVs that can be updated on the fly.

Changing process variables

Sign up

Login with SSO

Login to the community

Login with SSO