Embed

//Parent Domain and Embedded
class ParentObject {
    EmbedObject emObject
    static embedded = ['emObject']

    Set<EmbedObject> getItems(){
        def listOfParents = ParentObject.findAll()
        return listOfParents*.emObject as Set
    }
}

class EmbedObject {
    String embedObjectName
}

//Parent Controller
def index() {
        def parentObj = new ParentObject()
        parentObj.id = 1
        parentObj.emObject = new EmbedObject(embedObjectName: "Em Object Name")

        def parentObj2 = new ParentObject()
        parentObj2.id = 2
        parentObj2.emObject = new EmbedObject(embedObjectName: "Em Object Name 2")

        def parentObj3 = new ParentObject()
        parentObj3.id = 3
        parentObj3.emObject = new EmbedObject(embedObjectName: "Em Object Name 3")

        [parentObj, parentObj2, parentObj3]*.save(flush: true)

        def resultMap = [:]
        resultMap.embedObjectName = parentObj.emObject.embedObjectName
        resultMap.listOfEmObjects = parentObj.items*.embedObjectName

        render resultMap as JSON
    }


//Result JSON
{
    "embedObjectName": "Em Object Name",
    "listOfEmObjects": [
        "Em Object Name",
        "Em Object Name 2",
        "Em Object Name 3"
    ]
}