How to handle backend updates on UI

Question

Hi All,

Currently we are having a workflow which consists of a task which will be worked by a user. When any updates to the workflow occur from external system, we cannot show the updates to the user in the UI when user has the UI already open since the data cannot be refreshed. We are thinking of either cancelling and creating a new workflow with the latest updates or completing the task using smart service and recreating the task within the same workflow. Any insights on which will be better approach will be useful.

Harsha Sharma · Answer

Instead of cancelling/completing the task can you consider adding a refresh icon in the UI and train users to click on it intermittently to fetch latest data into the UI. Basically on click query latest data into the form using link configuration. Additionally on Submit button of form you can compare the latest data in db with the UI data to confirm if data is up to date or not. Form submission can be restricted if data doesn't match. 
 If the above doesn't suit your use case then you can configure exception timer in the UI node to end the process and provide users with an action to retrigger the action.

Stefan Helzle · Answer

You could add a banner message to the UI which is only shown if there is an update. Then allow the user to see what has changed and load the new data. 
 This is a bit more complex, but should result in a much better UX.

Shubham Aware · Answer

Use a!refreshVariable() with a refreshInterval of about 30 seconds to poll a lightweight data source holding an update flag, avoiding full form reloads. Show a subtle banner to notify users of external changes without forcing refresh or extra clicks. For critical updates, use a smart service in the process model to complete and recreate tasks, keeping audit trails intact. Optimize performance by refreshing only essential data and avoiding refreshAlways=true. Clearly inform users about possible external updates and encourage frequent saving. Note that true real-time updates under 30 seconds aren&rsquo;t natively supported in Appian.

Harsha Sharma · Answer

Unknown said: We cannot perform the data comparison because there is a chance user might modify the data due to some reason and the data from external system might be something different 
 One way to do this is to keep populate a local variable with form data and not updating it at all anywhere in UI. Only use of this will be in comparing the data at load with data from database table. You can do a check every 30s using refreshVariable() or on Submit button action. If they don't match show the users a banner with action to refresh/load latest data.

Mathieu Drouin · Answer

There is a recipe that could be helpful for this: https://docs.appian.com/suite/help/25.2/recipe-refresh-until-asynchronous-action-completes.html 
 You can also go further and have events pushed to the UI in realtime via this plugin: https://community.appian.com/b/appmarket/posts/sail-events-field

Harsha Sharma · Answer

As I mentioned you can do this check during submit or button action also. Refresh variables can cause performance so try comparing data in a button saveinto and if mismatch is found then show a banner message to re load the form! You can setup variables to show information cards to users when mismatch is found using showwhen. 
 Generally amongst many options one easy solution is that users are informed that the data is outdated so they can refresh the form or cancel the current form and re open the task!