Ion Schema Kotlin
A reference implementation of the Ion Schema Specification, written in Kotlin.
Getting Started
The following kotlin and java code samples are a simple example of how to use this
API. The Customer type is a struct that requires firstName and lastName fields as strings, while the
middleName field is optional ( To keep things simple, the schema is loaded
inline ).
Kotlin
import com.amazon.ion.system.IonSystemBuilder
import com.amazon.ionschema.IonSchemaSystemBuilder.Companion.standard
import com.amazon.ionschema.Type
object IonSchemaGettingStarted {
private val ION = IonSystemBuilder.standard().build()
@JvmStatic
fun main(args: Array<String>) {
val iss = standard()
.build()
val schema = iss.newSchema(
"""
type::{
name: Customer,
type: struct,
fields: {
firstName: { type: string, occurs: required },
middleName: string,
lastName: { type: string, occurs: required },
},
}
"""
)
val type = schema.getType("Customer")
checkValue(type, """ { firstName: "Susie", lastName: "Smith" } """)
checkValue(type, """ { firstName: "Susie", middleName: "B", lastName: "Smith" } """)
checkValue(type, """ { middleName: B, lastName: Washington } """)
}
private fun checkValue(type: Type?, str: String) {
val value = ION.singleValue(str)
val violations = type!!.validate(value)
if (!violations.isValid()) {
println(str)
println(violations)
}
}
}Java
import com.amazon.ion.IonSystem;
import com.amazon.ion.IonValue;
import com.amazon.ion.system.IonSystemBuilder;
import com.amazon.ionschema.AuthorityFilesystem;
import com.amazon.ionschema.IonSchemaSystem;
import com.amazon.ionschema.IonSchemaSystemBuilder;
import com.amazon.ionschema.Schema;
import com.amazon.ionschema.Type;
import com.amazon.ionschema.Violations;
public class IonSchemaGettingStarted {
private static IonSystem ION = IonSystemBuilder.standard().build();
public static void main(String[] args) {
IonSchemaSystem iss = IonSchemaSystemBuilder.standard()
.build();
Schema schema = iss.newSchema(" type::{\n" +
" name: Customer,\n" +
" type: struct,\n" +
" fields: {\n" +
" firstName: { type: string, occurs: required },\n" +
" middleName: string,\n" +
" lastName: { type: string, occurs: required },\n" +
" },\n" +
" }\n")
;
Type type = schema.getType("Customer");
checkValue(type, "{ firstName: \"Susie\", lastName: \"Smith\" }");
checkValue(type, "{ firstName: \"Susie\", middleName: \"B\", lastName: \"Smith\" }");
checkValue(type, "{ middleName: B, lastName: Washington }");
}
private static void checkValue(Type type, String str) {
IonValue value = ION.singleValue(str);
Violations violations = type.validate(value);
if (!violations.isValid()) {
System.out.println(str);
System.out.println(violations);
}
}
}When run, the code above produces the following output:
{ middleName: B, lastName: Washington }
Validation failed:
- one or more fields don't match expectations
- firstName
- expected range::[1,1] occurrences, found 0
- middleName: B
- expected type string, found symbol
- lastName: Washington
- expected type string, found symbol
Development
This repository contains two git submodules: ion-schema-tests and ion-schema-schemas. Both are used by this library's unit tests.
The easiest way to clone the ion-schema-kotlin repository and initialize its submodules
is to run the following command:
$ git clone --recursive https://github.com/amzn/ion-schema-kotlin.git ion-schema-kotlin
Alternatively, the submodule may be initialized independently from the clone by running the following commands:
$ git submodule init
$ git submodule update
ion-schema-kotlin may now be built with the following command:
$ gradle build
Pulling in Upstream Changes
To pull upstream changes into ion-schema-kotlin, start with a simple git pull.
This will pull in any changes to ion-schema-kotlin itself (including any changes
to its .gitmodules file), but not any changes to the submodules.
To make sure the submodules are up-to-date, use the following
command:
$ git submodule update --remote
For detailed walkthroughs of git submodule usage, see the Git Tools documentation.
Roadmap
The roadmap is organized as a series of milestones.
License
This library is licensed under the Apache 2.0 License.