An implementation of JSON Schema, based on IETF's draft v4 - Go language
References :
- http://json-schema.org
- http://json-schema.org/latest/json-schema-core.html
- http://json-schema.org/latest/json-schema-validation.html
go get github.com/juju/gojsonschema
Dependencies :
- https://github.com/juju/gojsonpointer
- https://github.com/juju/gojsonreference
- https://github.com/stretchr/testify/assert
package main
import (
"fmt"
"github.com/juju/gojsonschema"
)
func main() {
schemaLoader := gojsonschema.NewReferenceLoader("file:///home/me/schema.json")
documentLoader := gojsonschema.NewReferenceLoader("file:///home/me/document.json")
result, err := gojsonschema.Validate(schemaLoader, documentLoader)
if err != nil {
panic(err.Error())
}
if result.Valid() {
fmt.Printf("The document is valid\n")
} else {
fmt.Printf("The document is not valid. see errors :\n")
for _, desc := range result.Errors() {
fmt.Printf("- %s\n", desc)
}
}
}
There are various ways to load your JSON data. In order to load your schemas and documents, first declare an appropriate loader :
- Web / HTTP, using a reference :
loader := gojsonschema.NewReferenceLoader("http://www.some_host.com/schema.json")- Local file, using a reference :
loader := gojsonschema.NewReferenceLoader("file:///home/me/schema.json")References use the URI scheme, the prefix (file://) and a full path to the file are required.
- JSON strings :
loader := gojsonschema.NewStringLoader(`{"type": "string"}`)- Custom Go types :
m := map[string]interface{}{"type": "string"}
loader := gojsonschema.NewGoLoader(m)And
type Root struct {
Users []User `json:"users"`
}
type User struct {
Name string `json:"name"`
}
...
data := Root{}
data.Users = append(data.Users, User{"John"})
data.Users = append(data.Users, User{"Sophia"})
data.Users = append(data.Users, User{"Bill"})
loader := gojsonschema.NewGoLoader(data)Once the loaders are set, validation is easy :
result, err := gojsonschema.Validate(schemaLoader, documentLoader)Alternatively, you might want to load a schema only once and process to multiple validations :
schema, err := gojsonschema.NewSchema(schemaLoader)
...
result1, err := schema.Validate(documentLoader1)
...
result2, err := schema.Validate(documentLoader2)
...
// etc ...To check the result :
if result.Valid() {
fmt.Printf("The document is valid\n")
} else {
fmt.Printf("The document is not valid. see errors :\n")
for _, desc := range result.Errors() {
fmt.Printf("- %s\n", desc)
}
}gojsonschema uses the following test suite :