I am creating a custom vision component that pushes values into the properties of other vision components on the window. Normally to do this, I would have to set up an expression on the downstream component property to accept a value from one tag or the other, depending on a specific case. For insta…

[image] Porter_Ellis: because the subscription for the binding is created before my shim provider has been created When are you installing your shim? (It should be in your ClientHook.startup() method. Or perhaps in the constructor.)

If a subscriptions value source changes, how is the subscription itself supposed to know that without refreshing? This is my 'subscribe' method in the wrapper: public CompletableFuture<Void> subscribe() { if (isSubscribed) { return CompletableFuture.completedFuture(null); …

Your wrapper should have been given a tag change listener to which to deliver notifications. Your wrapper should pass on notifications from the real tag provider when not simulating, and should generate any desired notifications when simulating.

I have my program in a state where 'default' is being overwritten with my new provider and historical values are making it to the tags. However, because the realtime tag changes are always executing, both my historical tag changes and the realtime tag changes are being written into the tag at the sa…

Your shim should be receiving real time tag changes all the time. Your shim should be generating historical events only when your simulation state says to. Your shim is entirely in control of this, and should be able to intelligently decide what events to pass on to the real consumer.

Ah I understand. I have been mixing up where I should override the tagChanged() method. I will try it from the provider and see how it goes.

No matter what I have tried, I am still required to refresh the binding in order to receive my newly created values into a component property. After reviewing the debug logs, I noticed this: 09:57:47.790 [DesignerExecEngine-1] DEBUG tags.subscriptions -- Subscribing, paths= [[default]Blink…

That doesn't look at all like what I would expect for a subscription object. I would expect your subscription object to: Handle tag changes from the real time system at all times, by capturing the last received value unconditionally, and calling the consumer's listener when not simulating. (Tha…

You mentioned the 'consumer' in the context of both the realtime provider and my shim provider. You also mentioned that the consumer has a singular listener. Can you elaborate on what you mean by 'consumer'?

When a binding subscribes to a tag, it hands the tag provider a tag change listener. That is the real consumer. Your shim must save that in a final field when creating the intermediate tag change listener your shim will hand to the real tag provider. Your shim's intermediate listener objects must…

How do I access a tag change listener that has been created and attached to the binding outside of my code? I already keep track of the most recent QV in my wrapper. I think the only piece I am missing is the real consumer tag change listener. I am also already keeping track of intermediate listener…

Create Customizer with Property dropdown

Module Development

ryan.white August 19, 2025, 4:26pm 52