Reflector 's Mapper callback

[swaggest]

Reflector 's Mapper callback

[tpoxa]

That's awesome. Thanks @vearutop

[vearutop]

There is an InterceptType option that allows schema customization based on its reflect.Value.
(All available options are listed at https://pkg.go.dev/github.com/swaggest/jsonschema-go#Reflector.Reflect)

https://go.dev/play/p/hZgF5vsks1R

package main

import (
	"encoding/json"
	"fmt"
	"reflect"

	"github.com/swaggest/jsonschema-go"
)

func main() {
	type CustomParameter interface{}

	// User is used as a base to provide tests for comments.
	type User struct {
		Param interface{} `json:"param" title:"Param"`

		// Unique sequential identifier.
		// Name of the user
		Dynamic CustomParameter `json:"dynamic" title:"Test"`
		//Some interface{} `json:"some,omitempty" jsonschema_extras:"requiredWhen=[1,2,3]"`
	}

	r := jsonschema.Reflector{}

	defs := map[string]jsonschema.Schema{}

	r.DefaultOptions = append(r.DefaultOptions,
		jsonschema.DefinitionsPrefix("#/$defs/"),
		jsonschema.CollectDefinitions(func(name string, schema jsonschema.Schema) {
			defs[name] = schema
		}),
		jsonschema.InterceptType(func(value reflect.Value, schema *jsonschema.Schema) (bool, error) {
			r := value.Type()

			// Nil interfaces arrive as pointer wraps.
			if r.Kind() == reflect.Ptr {
				r = r.Elem()
			}

			if r.Name() == "" {
				return false, nil
			}

			if r.Kind() == reflect.Interface {
				// Making new definition.
				s := jsonschema.Schema{}
				s.AddType(jsonschema.Object)
				s.WithExtraPropertiesItem("configurable", true)
				defs[r.Name()] = s

				// Replacing current schema with reference.
				rs := jsonschema.Schema{}
				rs.WithRef(fmt.Sprintf("#/$defs/%s", r.Name()))
				*schema = rs

				// Alternatively, in this case schema can be updated instead of replacing,
				// because it would be empty for an interface.
				//
				//schema.WithRef(fmt.Sprintf("#/$defs/%s", r.Name()))

				// True return disables further schema processing.
				return true, nil
			}

			return false, nil
		}))

	sh, _ := r.Reflect(User{})
	sh.WithExtraPropertiesItem("$defs", defs)

	j, _ := json.MarshalIndent(sh, "", " ")
	fmt.Println(string(j))
}

{
 "properties": {
  "dynamic": {
   "$ref": "#/$defs/CustomParameter",
   "title": "Test"
  },
  "param": {
   "title": "Param"
  }
 },
 "type": "object",
 "$defs": {
  "CustomParameter": {
   "type": "object",
   "configurable": true
  }
 }
}