Is it possible to enhance the ZEN functions by adding custom ones?

[antback]

Hi,

Is it possible to add custom functions to the ZEN language? I have a use case to include a fuzzy string match in a rule. This is just an example, it would be great to be able to define custom functions. It doesn't seems possible right now.

Thanks.

[stefan-gorules]

Hi @antback,

Currently this is not possible. This is a part of the gap that we are planning to solve with Custom Functions soon. Custom functions are nodes that can implement custom logic.

Regarding extending ZEN Expressions (language) itself, this will unlikely be ever possible. However we are always looking to expand on the language and if you can explain the use case and propose an API (e.g. startsWith("helloWorld", "hello")) we can consider adding it.

[antback]

HI @stefan-gorules,

My use case is to apply different kink of matching functions not provided by default, for example the one I mentioned, to do a fuzzy comparison.

About the Custom Functions you mention, how the cutom logic will be implemented? Using the ZEN language?

Thanks.

[stefan-gorules]

It would be implemented in Rust and made available to ZEN language if we find it to be useful for wide array of use cases.

You may also implement it in JS functions (already), however this makes it harder for business users to write their own rules, and comes with performance considerations.

Could you kindly provide full list of comparison functions that you would need?

[edwmurph]

Looks like there's an open PR for this? Any updates on when this feature might be released? Is there any way to get an early look and test out the new custom node functionality at this time?

I'm working on a POC this week to consider using this tool for my org's use case as an alternative option to JSONLogic

[ivanmiletic]

We didn't see that issue before, Custom Nodes are not officially "released".
What is the browser that you are using?

[edwmurph]

I understand if I just need to wait. I am seeing this issue in chrome, safari and edge. And I created this code sandbox as a minimum reproducible example

[ivanmiletic]

Ill check tomorrow with other members of the team if they can reproduce it

[coryjamescrook]

Hi! I've been keeping my eye on this thread for a while, but hasn't had much movement. Has there been any movement on the custom nodes for the zen engine? I have a few use cases where an external API fetch would be necessary, but with so little documentation around it, it's tough to understand the implementation of it.

The other limitation I think that may be prohibitive on my use cases are the timeout for a node of 50ms. Not sure if that is something that applies to a custom node or not.

Would love to hear more about it though! I'd be willing to contribute to help out with docs, etc, if it would help move it along quicker.

Keep up the great work, this engine is great! Cheers

[antback]

I saw the recent publishes and was able to mostly get a POC working for my use case but am facing one last issue with the jdmeditor where if custom nodes are added, then the node dropdowns won't stay open. Does this sound familiar or are there any leads you could recommend?
trim.E6957FA3-CF33-4593-A99C-4D44AEBF09BD.MOV

Hi @edwmurph, were you able to fix this issue? Same is happening to me.

Thanks.

[ivanmiletic]

@edwmurph issue is in providing customNodes https://codesandbox.io/p/devbox/xmjn96?file=%2Fsrc%2FApp.jsx%3A28%2C9&migrateFrom=dlc2nj

Instead of re-create custom nodes you should do:

const customNodes = useMemo(() => {
    return [
      createJdmNode({
        kind: "pingNode",
        displayName: "Ping",
        group: "ping",
        shortDescription: "Used for ping",
      }),
    ];
  }, []);

Same with components.

But please note it is not yet "released" we might do some enhancements in upcoming days

[edwmurph]

ah that worked thank you so much!

[Cosmo439]

Is there an ETA for releasing CustomNodes? Or are there any examples of how to use them experimentally?

[stefan-gorules]

Hi @Cosmo439,

Custom nodes have been released already. There isn't any extensive documentation about them yet, however, you can see an example of how to add them in:

Frontend - https://gorules.github.io/jdm-editor/?path=/story/decision-graph--custom-node
Backend (Go) - https://github.com/gorules/zen-go/tree/master/examples/custom-node

In all languages, approach is similar. You are given a custom node along with it's properties, and you need to return some data from those.

[Ghilteras]

@stefan-gorules could you please clarify how to add custom nodes to the UI? The link you provided just shows them already added to the UI, not the process to make them appear. I am happy to add the ones in the example folder you linked above into our BRMS instance. I am using the docker-compose one, but I can switch to k8s if it's easier.

[Cassielxd]

Since the official closed this extension, this is a secondary development based on zen https://github.com/Cassielxd/moduforge-rs/blob/main/crates/expression/examples/custom_function_demo.rs Added a custom extension implementation