Page data processors

[freiksenet]

GraphQL allows custom scalars. However page data only allows json serializable data. It would be convinient to enable defining processors for page-data that convert the data to a richer format. That would help for types like Date but also for future features like Renderable (#18976).

This can be done by defining a client resolve function. Those functions would be included in the common bundle and called when a certain type is encountered in page-data.json. For instance for a backwards compatible date type it could be as follows:

function dateProcesor(value, args) {
  if (args.asJsDate) {
     return new Date(value)
  } else {
    return value
  }
}

And for Renderable type in could run a require on the value and return a component export.

[freiksenet]

Alternatively @vladar suggested that it could be a directive.

{
  imageSharp {
    fluid(...someParams) @asComponent {
      ...SomeFragment
    }
  }
}


  mdx {
    content @asComponent
  }
}