Create custom json definition in play scala - scala

Question

I'm new to Scala and I'm learning Scala and Play Framework:
I'm trying to dynamically create a Json with play/scala starting from a sequence of data named "tables" by using Map(...), List(...) and Json.toJson(...).
My result should be like the code resultCustomJsonData shown below
var resultCustomJsonData = [
{
text: "Parent 1",
nodes: [
{
text: "Child 1",
nodes: [
{
text: "Grandchild 1"
},
{
text: "Grandchild 2"
}
]
},
{
text: "Child 2"
}
]
},
{
text: "Parent 2"
},
{
text: "Parent 3"
},
{
text: "Parent 4"
},
{
text: "Parent 5"
}
];
my scala code is this below:
val customJsonData = Json.toJson(
tables.map { t => {
Map(
"text" -> t.table.name.name, "icon" -> "fa fa-cube", "nodes" -> List (
Map( "text" -> "properties" )
)
)
}}
)
but i'm getting this error:
No Json serializer found for type Seq[scala.collection.immutable.Map[String,java.io.Serializable]]. Try to implement an implicit Writes or Format for this type.

Answer 1

Here is a way to do it without using temporary Map:
import play.api.libs.json.Json
val customJsonData = Json.toJson(
tables.map { t =>
Json.obj(
"text" -> t.table.name.name,
"icon" -> "fa fa-cube",
"nodes" -> Json.arr(Json.obj("text" -> "properties"))
)
}
)

Answer 2

I think you should try implement custom serializer/writer. Check here.
For example:
implicit val userWrites = new Writes[User] {
def writes(user: User) = Json.obj(
"id" -> user.id,
"email" -> user.email,
"firstName" -> user.firstName,
"lastName" -> user.lastName
)
}