Example of Use of renderMethod

[anthonycamilleri]

The renderMethod property is currently at risk. In the European Digital Credentials for Learning implementation, renderMethods are a critical part of the European Learning Model standard, which extends the VC spec.

The use case is that many countries in Europe will prescribe a specific visual look and feel for a credential by law, with the credential therefore needing to explicitly define the renderMethod and ensure that this is locked via the proof. Since no renderMethod currently exists, ELM has extended the data model with a class called elm:DisplayParameter which is described here: SHACL constraints for European Digital Credentials application profile (europa.eu).

The approach currently taken by ELM is to embed an image file directly in the credential, although using integrity protection would be another good way to go about it.

Should renderMethod be included in the standard, it would allow the next version of ELM to deprecate DisplayParameter, and go towards a standards compliant approach.

[msporny]

That's great news @anthonycamilleri (that there is interest through the ELM standard for render methods). We (the Working Group) have been so focused on finalizing the v2.0 core data model and data integrity that it's been difficult to find time to move renderMethod forward, even though we know that many ecosystems are now requiring it.

There is work being incubated in the W3C Credentials Community Group that might also be of interest to ELM:

https://w3c-ccg.github.io/vc-render-method/#the-rendermethod-property

Specifically, we'd love your input on this issue:

w3c-ccg/vc-render-method#9

If we can get agreement that renderMethod would be a useful property for v2.0, we could reserve it and ELM could continue to utilize their DisplayDetail object inside a renderMethod property on the VC.

Your general thoughts on all of these topics would be most welcome.

[PatStLouis]

@anthonycamilleri I'm currently working to bring an OCABundle render method to the vc-render-method spec.

You can look at the Overlays section of the spec to learn more about the capabilities OCA can bring to implementations. The core idea would consist in an OCABundle being published under some governance framework to provide a selection of overlays for software to render the credential depending on their needs.

We are currently doing this work in the scope of the UNTP specification but intend for this to be of general use case.

[iherman]

The issue was discussed in a meeting on 2024-05-29

• no resolutions were taken

View the transcript

5.1. Example of Use of renderMethod (issue vc-data-model#1480)

See github issue vc-data-model#1480.

Brent Zundel: renderMethod is currently at risk.
… European community is using these already.

Manu Sporny: there is a renewed...evolving interest in renderMethod.

Anil John: DHS is very interested in render method as well.

Manu Sporny: there are two or three variations coming from Singapore.

Dmitri Zagidulin: DCC and ASU in the US are implementing renderMethod as well.

Manu Sporny: there are some Australian and Canadian developers interested.
… these are all different approaches.
… so it's unlikely we can get a single example in the spec.

Dmitri Zagidulin: and can confirm that E.U. (the EU Learning Data Model team) is implementing renderMethod.

Manu Sporny: so we should probably remove it from VCDM 2.0 and get activity going in the CCG.

Brent Zundel: removing? what specifically? the feature? but keep the term as protected, correct?

Manu Sporny: yes.

Brent Zundel: good. so the term is there for use, but the contents are still undefined and under active development at the CCG.
… are there other actions here? or specific ones?

Dave Longley: +1 that render method is a vital tool for helping issuers to present VC information to holders in digital wallets (digital wallets that will not necessarily understand every piece of information in a decentralized world)... but lots of different explorations right now, definitely need to reserve it.

Ivan Herman: do we have a "next release" label? we should use that here.
… when we go out to the AC for the vote, we should make sure that this is something we are happy to work on later.
… and want their input, but we do not think we can solve it in the next 6 months.

Brent Zundel: any objections to adding the "future" label to this one?