How to pick up data from json with multiple level with scala - scala

Question

I want to pick up data from the json, but i can not code it in scala, i can only write it in php, because it is very simple to use, but i have no idea how can i do the same thing in scala. please help me out.
{
"home": {
"type": "literal",
"options": {
"route": "\/",
"defaults": {
"controller": "Apiv1\\Controller\\Index",
"action": "index"
}
}
},
"praise": {
"type": "literal",
"options": {
"route": "\/apiv1\/praise",
"defaults": {
"controller": "Apiv1\\Controller\\Praise",
"action": "index"
}
},
"may_terminate": true,
"child_routes": {
"status": {
"type": "literal",
"options": {
"route": "\/status",
"defaults": {
"action": "status"
}
}
}
}
},
"admin": {
"type": "literal",
"options": {
"route": "\/admin",
"defaults": {
"controller": "Admin\\Controller\\Index",
"action": "index"
}
},
"may_terminate": true,
"child_routes": {
"routes": {
"type": "literal",
"options": {
"route": "\/routes",
"defaults": {
"controller": "Admin\\Controller\\Routes",
"action": "index"
}
},
"may_terminate": true,
"child_routes": {
"list": {
"type": "literal",
"options": {
"route": "\/list",
"defaults": {
"action": "list"
}
}
}
}
}
}
}
}
I want to pick up the route field from the json, and i would like to list all routes
here is my php version function
function parseRoute($a, $pre = '', &$urls)
{
foreach ($a as $k => $v) {
$route = $pre . $v['options']['route'];
$urls[] = $route;
if (isset($v['child_routes']) && is_array($v['child_routes'])) {
$this->parseRoute($v['child_routes'], $route, $urls);
}
$route = null;
}
}
$urls = array();
var_dump(parseRoute(json_decode($data), '', $urls));

Answer 1

The best thing to do is to use one of the existing JSON libraries for Scala. Here is related question describing your options:
What JSON library to use in Scala?
Next is an example of using Lift-JSON. See the link, there are many examples. Here is what you can do:
import net.liftweb.json._
val rawJson = """{
"home":{
"type":"literal",
"options":{
"route":"/",
"defaults":{
"controller":"Apiv1\\Controller\\Index",
"action":"index"
}
}
},
"praise":{
"type":"literal",
"options":{
"route":"/apiv1/praise",
"defaults":{
"controller":"Apiv1\\Controller\\Praise",
"action":"index"
}
},
"may_terminate":true,
"child_routes":{
"status":{
"type":"literal",
"options":{
"route":"/status",
"defaults":{
"action":"status"
}
}
}
}
},
"admin":{
"type":"literal",
"options":{
"route":"/admin",
"defaults":{
"controller":"Admin\\Controller\\Index",
"action":"index"
}
},
"may_terminate":true,
"child_routes":{
"routes":{
"type":"literal",
"options":{
"route":"/routes",
"defaults":{
"controller":"Admin\\Controller\\Routes",
"action":"index"
}
},
"may_terminate":true,
"child_routes":{
"list":{
"type":"literal",
"options":{
"route":"/list",
"defaults":{
"action":"list"
}
}
}
}
}
}
}
}"""
val json = parse(rawJson)
val routeList = json \\ "route"
// which returns a structure like this:
JObject(List(JField(route,JString(/)), JField(route,JString(/apiv1/praise)), JField(route,JString(/status)), JField(route,JString(/admin)), JField(route,JString(/routes)), JField(route,JString(/list))))
// which is a JSON object
// if you want a list of routes as strings as in your example extract them this way now:
val routeList: List[String] = routeObject \\ classOf[JString]
// which returns:
List[String] = List(/, /apiv1/praise, /status, /admin, /routes, /list)
Note that I'm assuming that routes can be at any level of nesting in JSON doc (you might want to enforce certain level or parent of the 'route'). I also assume that all routes are Strings and ignore the ones which are not - if you want more options you can pattern match on the type of route using derivative classes of JValue: JArray, JString, JObject, etc.