graalson-trax

Javax.TRAX EE bindings for Graalson graaljs

https://docs.oracle.com/javase/8/docs/api/javax/xml/transform/TransformerFactory.html

Common pattern to transform JSON with Javascript directly on graal vm.

Load from json resource

    {
         "firstName": "John", "lastName": "Smith", "age": 25,
         "address" : {
             "streetAddress": "21 2nd Street",
             "city": "New York",
             "state": "NY",
             "postalCode": "10021"
         },
         "phoneNumber": [
             { "type": "home", "number": "212 555-1234" },
             { "type": "fax", "number": "646 555-4567" }
         ]
    }

Load transformer

    delete _.address['postalCode']

    let geo = lookupGeo(_.address),
    $ =  {
        name: _.firstName + ' ' + _.lastName,
        'year-of-birth': 2021-_.age,
        address : {
            ... _.address,
            geo
        },
        phoneNumber: _.phoneNumber.filter(p=>p.type == 'home')[0].number
    }

Call transform

    System.setProperty("javax.xml.transform.TransformerFactory", "au.com.devnull.graalson.trax.GraalsonTransformerFactory");

    Map<String, Object> config = new HashMap<>();
    config.put("spaces", Integer.valueOf(4));
    JsonWriterFactory wfactory = Json.createWriterFactory(config);
    JsonWriter jwriter = wfactory.createWriter(new PrintWriter(System.out));
    JsonReader jreader = Json.createReader(ClassLoader.getSystemClassLoader().getResourceAsStream("default.json"));

    Source template = new GraalsonSource("template1.js");
    Source source = new GraalsonSource(jreader);
    Result result = new GraalsonResult(jwriter);

    TransformerFactory.newInstance().newTemplates(template).newTransformer().transform(source, result);

Output

    {
        "address": {
            "streetAddress": "21 2nd Street",
            "city": "New York",
            "state": "NY",
            "country": "Javaland"
        },
        "phoneNumber": "212 555-1234",
        "name": "John Smith",
        "year-of-birth": 1996
    }

Add dependency

    <dependency>
        <groupId>biz.mofokom</groupId>
        <artifactId>graalson-trax</artifactId>
        <version>1.0.0</version>
    </dependency>