Move properties on the WebformElement interface

Starting on this.

The GraphQL specification actually required fields defined on an interface to be duplicated across all the types that implement the interface.

I mistakenly thought we could generate a schema like this:

interface WebformElement {
  key: String!
  title: String
  description: String
  multiple: Int
  required: WebformRequiredElement
  type: String!
}

interface WebformElementMultipleValuesBase {
  multipleValues: WebformElementMultipleValues
}

type WebformElementAddress implements WebformElement & WebformElementMultipleValuesBase {
}

type WebformElementCaptcha implements WebformElement {
}

But the GraphQL interface specification actually _requires_ the fields to be duplicated on the implementors, with the motivation that this makes it easier to declare covariant types.

So it quickly becomes bloated like this:

interface WebformElement {
  key: String!
  title: String
  description: String
  multiple: Int
  required: WebformRequiredElement
  type: String!
}

interface WebformElementMultipleValuesBase {
  multipleValues: WebformElementMultipleValues
}

type WebformElementAddress implements WebformElement & WebformElementMultipleValuesBase {
  key: String!
  title: String
  description: String
  multiple: Int
  required: WebformRequiredElement
  type: String!
  multipleValues: WebformElementMultipleValues
}

type WebformElementCaptcha implements WebformElement {
  key: String!
  title: String
  description: String
  multiple: Int
  required: WebformRequiredElement
  type: String!
}

Since we are still building out the schema it is easy to see how this can bloat the schema exponentially.

A good solution to limit this could be to define only a single element on an interface, for example:

interface WebformElement {
  metadata: WebformElementMetadata!
}

interface WebformElementMultipleValuesBase {
  multipleValues: WebformElementMultipleValues
}

type WebformElementMetadata {
  key: String!
  title: String
  description: String
  multiple: Int
  required: WebformRequiredElement
  type: String!
}

type WebformElementAddress implements WebformElement & WebformElementMultipleValuesBase {
  metadata: WebformElementMetadata!
  multipleValues: WebformElementMultipleValues
}

type WebformElementCaptcha implements WebformElement {
  metadata: WebformElementMetadata!
  type: String!
}

Which is incidentally how it was in version 2.x-alpha1, but this got flattened out as part of the change request ✨ Remove Metadata subfields Fixed .

It is probably a good idea to revisit this, and to reconsider adding back the metadata field to limit schema bloat.

We should also take other measures to limit the size of the schema. For example we should not expose all field types by default.

Unassigning, let's first figure out the best way to approach this.

I would also appreciate to have a reduced schema, having a field for "common" element fields would indeed reduce the schema significantly and make it easier to add new custom fields for all elements. Possible frontend implementations might also "work" in this way: The common fields (such as label, description, help, states, required, etc.) are usually rendered the same (as label tags, help texts below the actual input), no matter what the element type is. And since these are available on all webform element plugins, it makes sense to group them into a separate type.

Thanks for the feedback @dulnan! I will implement this.

LGTM! Thank you

Thanks!

Automatically closed - issue fixed for 2 weeks with no activity.