jsonschema

Documentation

Overview

Package jsonschema provides JSON Schema Draft 4 encoding support for schema.Schema. Note that the current implementation is incomplete, and not all FieldValidator types are yet supported. Custom validators are also not supported at the moment.

Index

• Variables
• type Builder
  • func ValidatorBuilder(v schema.FieldValidator) (Builder, error)
• type Encoder
  • func NewEncoder(w io.Writer) *Encoder
  • func (e *Encoder) Encode(s *schema.Schema) error

Examples

• Encoder

Variables

var (
	//ErrKeysValidatorNotSupported is returned when Dict.KeysValidator is not a
	//*schema.String instance or nil.
	ErrKeysValidatorNotSupported = errors.New("KeysValidator type not supported")
)

var (
	//ErrNoSchema is returned when trying to JSON Encode a schema.Object with
	//the Schema property set to nil.
	ErrNoSchema = errors.New("no schema defined for object")
)

var (
	//ErrNoSchemaList is returned when trying to JSON Encode an empty
	//schema.AnyOf or schema.AllOf slice.
	ErrNoSchemaList = errors.New("at least one schema must be specified")
)

var (
	// ErrNotImplemented is returned when the JSON schema encoding logic for a
	// schema.FieldValidator has not (yet) been implemented.
	ErrNotImplemented = errors.New("not implemented")
)

Types

type Builder

type Builder interface {
	// BuildJSONSchema should return a map containing JSON Schema Draft 4
	// properties that can be set based on FieldValidator data. Application
	// specific properties can be added as well, but should not conflict with
	// any legal JSON Schema keys.
	BuildJSONSchema() (map[string]interface{}, error)
}

The Builder interface should be implemented by custom schema.FieldValidator implementations to allow JSON Schema serialization.

func ValidatorBuilder

func ValidatorBuilder(v schema.FieldValidator) (Builder, error)

ValidatorBuilder type-casts v to a valid Builder implementation or returns an error.

type Encoder

type Encoder struct {
	// contains filtered or unexported fields
}

Encoder writes the JSON Schema representation of a schema.Schema to an output stream. Note that only a sub-set of the FieldValidator types in the schema package is supported at the moment. Custom validators are also not yet handled. Attempting to encode a schema containing such fields will result in a ErrNotImplemented error.

Example

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"math"

	"github.com/entropyinf/rest-layer/schema"
	"github.com/entropyinf/rest-layer/schema/encoding/jsonschema"
)

func main() {
	s := schema.Schema{
		Fields: schema.Fields{
			"foo": schema.Field{
				Required:  true,
				Validator: &schema.Float{Boundaries: &schema.Boundaries{Min: 0, Max: math.Inf(1)}},
			},
			"bar": schema.Field{
				Validator: &schema.Integer{},
			},
			"baz": schema.Field{
				Description: "baz can not be set by the user",
				ReadOnly:    true,
				Validator:   &schema.String{MaxLen: 42},
			},
			"foobar": schema.Field{
				Description: "foobar can hold any valid JSON value",
			},
		},
	}
	b := new(bytes.Buffer)
	enc := jsonschema.NewEncoder(b)
	enc.Encode(&s)
	b2 := new(bytes.Buffer)
	json.Indent(b2, b.Bytes(), "", "| ")
	fmt.Println(b2)
}

Output:

{
| "additionalProperties": false,
| "properties": {
| | "bar": {
| | | "type": "integer"
| | },
| | "baz": {
| | | "description": "baz can not be set by the user",
| | | "maxLength": 42,
| | | "readOnly": true,
| | | "type": "string"
| | },
| | "foo": {
| | | "minimum": 0,
| | | "type": "number"
| | },
| | "foobar": {
| | | "description": "foobar can hold any valid JSON value"
| | }
| },
| "required": [
| | "foo"
| ],
| "type": "object"
}

func NewEncoder

func NewEncoder(w io.Writer) *Encoder

NewEncoder returns a new JSONSchema Encoder that writes to w.

func (*Encoder) Encode

func (e *Encoder) Encode(s *schema.Schema) error

Encode writes the JSON Schema representation of s to the stream, followed by a newline character.