Cuelang for data validation

[gedw99]

I have been playing with Cuelang and golang .

https://cuelang.org/docs/usecases/

https://cuelang.org/docs/usecases/

Cuelang is heavily mated to golang . It even has versioning based on cue.mod and cue.sum.

You can think of it as an interpreted language .

It can pull in json and output json also .

so I was thinking about how it can be used to do server side validation . The user could extend graphjin at runtime in various ways

Workflows where when something change a workflow is kicked off

Data validation for anything that can’t be enforced by the relational constraints that the db provides.

[dosco]

I'm very open to exploring this further. I just committed support for server side validations and this might be a way to improve on that.

mutation createUser
@constraint(variable: "email", format: "email", min: 1, max: 100) 
@constraint(variable: "full_name", requiredIf: { id: 1007 } ) {
  users(insert: { id: $id, email: $email, full_name: $full_name }) {
    id
    email
    full_name
  }
}

[gedw99]

Ok great . i will have a look at it.

[gedw99]

i see your using https://github.com/go-playground/validator

As far as i know that designed for validation of structs and so implies it is only useful at compile time.

Cue Lang can be added at runtime, which is complementary to the premise of GraphJin.

SO what we need to do is work out the best usage of CueLang for the use cases that we see are pertinent to GraphJib.

1. Mutation to Server, requires that basic validation be done. For example email address, age is greater than 16 years ( yes CueLang can do maths at runtime ).

2. probably a few more.

---

Then the architectural implementation of it:

How to we want to allow the user at runtime add a CueLang validation ?

What do we map a CueLang validation to ?

Where do we store the CurLang files ? Pretty sure that the DB is the right place, so that they travel with backup / restore.

anything else ?

[dosco]

We are using go-playground/validator v10 which supports runtime validation using the ValidateMap method. Having to learn a new language like cuelang could be a non-starter but if we could compile our validations to cuelang internally and use their code to handle the actual validations it would be great.

[ehsanonline]

I just installed GraphJin today. so I consider my self a starter! it is amazing and definitely deserves more stars.
One things that holds me to use it in the future or on actual projects is validation. the Cuelang idea looks promising and it was easy to lean too. so I think GraphJin users should use the whole power of it.

[dosco]

The validation code is pretty easy to experiment with if anyone wants to take the lead here. The function to update would be validateAndUpdateVars in core/core.go

[ehsanonline]

@gedw99 Check this out :
#361 (comment)

[dosco]

Sorry I just saw this. interesting taking a look now.

[gedw99]

Looks amazing !! This is really great work .

But @dosco is right about only one code path . KISS . One step at a time

[dosco]

FYI This has been merged so it's available to use. As for not exposing the query and validation to the client. I'm currently working on a REST endpoint for GraphJin so queries can be called just by name and without having a copy of the query in the client.

Also I'm changing the allow list to be pure .gql files to take advantage of linters and prettier in the editor. The idea is to allow folks to write queries as .gql files in the server and then call then via the REST api. This will move GraphJin from a pure GraphQL service to a build REST APIs with GraphQL if that makes sense.

[gedw99]

So the equivalent of “stored procedures “ , where as you said you have a name for the query and the paeans for it . This I guess also makes validation easier in that you know the paeans and so what needs validation.

The REST API sounds nice. Will this be accessible from the cli / ctl ? So we can imitate being a user X and do a ‘list all stored procedures”, etc.

I really like where this is heading !

[gedw99]

Btw I think cuelang is way way off

I was inspired by Benthos that added CueLang to act as DSL to allow them to build a GUI on top of Benthos.
it’s worth digging into their code and docs . It’s well explained in their docs better than me.

https://www.benthos.dev/docs/configuration/using_cue/

Cue Lang allowed them to build this gui: https://studio.benthos.dev/. It’s not open source.

[dosco]

How do you mean? We do support culang for validation.