I have an enum with values
enum class Foo(val serverVal:Int) {
BAR(1),
BUG(2)
}
that I would like to use with a class:
data class C1(val fooVal:Foo)
I want to be able to serialise it with a code that looks as close as can be to:
Gson().toJson(C1(Foo.BAR))
That would yield
{"fooVal":1}
Instead of the default conversion, which is, of course {"fooVal":"BAR"}. If it was a string value I could have used #SerializedName, but I can't because it's an Int, not a String.
Is there a simple way to add something to Foo, in order to show Gson how to take the Int value from Foo entries rather than their name?
Examples I saw in Java include EnumAdapterFactory and TypeAdapter which are quite cumbersome and defeat the purpose of a pretty code.
I would love to get a solution that is maintained inside the data structure.
enum class SomeEnum(val i:Int) {
V1(1), V2(10), V3(5);
companion object {
#SerializeMeLikeThis
fun toJson() = i;
#DeserializeMeLikeThat
fun fromJson(v:Int) = values().find{it.i == v}?:whatever
}
}
An ugly way but still encapsulated-ish
data class C2(#SerializedName("foo") var serverFoo:Int) {
// Becomes a nightmare with many params.
constructor(f:Foo) : this(F.serverVal)
var foo:Foo
get() = Foo.values().find{serverFoo == it.serverVal}?:whatever
set(v) { serverFoo = v.serverVal }
}
So it can be called
Gson().toJson(C2(BAR))
and
// Result: Foo.BAR
Gson().fromJson("""{"foo":"1"}""", C2::class.java).foo
Well, you can live on it...but it... :-(
Any nice way?
Thanks
Related
Hello I have a problem with my JSON. I am using OkHTTPClient to get JSON from web - to get objects from JSON using kotlinx.serialization via method which contains this and return value from method should be Result :
private suspend inline fun <reified T> OkHttpClient.get(webUrl: HttpUrl): Result<T> =
try {
//Builder defined here ... but skipping this line of code
val data = Json { ignoreUnknownKeys = true }.decodeFromString<T (result.body!!.string())
Result.Success(data)
} catch (e: Exception) {
Result.Failure(e)
}
suspend fun getFact(): Result<Fact> =
client.httpGet("myURL".toHttpUrl())
Json from myURL:
{"status":"success","data":[{"fact":"This is random information i need to get"}],"message":"Retrieved Fact"}
My serializer and Serializable data classes:
#Serializable
data class Fact(
#Serializable(with = FactListSerializer::class)
val data: String) java.io.Serializable
object FactListSerializer : JsonTransformingSerializer<List<String>>(ListSerializer(String.serializer())) {
override fun transformDeserialize(element: JsonElement): JsonElement {
return if (element is JsonArray) {
JsonArray(listOf(element)).first()
} else {
element
}
}
}
To be honest I am not sure what I am doing, but I am getting this error all the time when I print val fact = api.getFact():
Fact: Failure(error=kotlinx.serialization.json.internal.JsonDecodingException: Expected JsonPrimitive at 0, found {"fact":"This is random information i need to get"}
What I need to return is only first element of array fact, because JSON obtain always only 1 fact inside array. So I don't want to return from Serializer/Json List but only Fact object.
But as you see I am obtaining always Result Fauilure, don't know why. My goal is to obtain Result Success and obtaining from that JSON object Fact (only one), but I am not sure if I am doing it correct (obviously not) and even if it is even possible to return from JSONArray only one object (element of type Fact).
So what I expect is something like this:
Fact: Success(value=Fact(fact=This is random information i need to get))
I think the deserializer definition should be changed on 3 levels. The example of how to use JsonTransformingDeserializer in the docs actually describes most of what you need.
JsonArray(listOf(element)).first() should just be element.first(). Here you're building a JsonArray containing your initial JsonArray as only element, and then taking the first, so you basically get back the exact same element.
The type parameter T of JsonTransformingSerializer is supposed to be the type of the property it's applied to, so you should at least get a warning in the code because yours is defined to work on List<String> but is applied to a String property. It should be JsonTransformingSerializer<String>(String.serializer()).
You not only need to unwrap the data array, you also need to extract the value of the fact key within the element of that array.
So with all these changes, it should give something like this:
object FactListSerializer : JsonTransformingSerializer<String>(String.serializer()) {
override fun transformDeserialize(element: JsonElement): JsonElement {
val unwrappedData = if (element is JsonArray) element.first() else element
return unwrappedData.jsonObject["fact"] ?: error("missing 'fact' key in 'data' array")
}
}
Is it possible to do something similar to this in Haxe?
private var _bindingsFiltered:Vector<String>;
_bindingsFiltered = new Vector<String>();
_controller_touched_binding.action = "meta_start";
What I would like to be able to do:
_bindingsFiltered[_controller_touched_binding.action] = "BUTTON_13";
trace(_bindingsFiltered["meta_start"]); //result: "BUTTON_13"
I want to be able to override a specific index too (still accessed via a string), with a new value, rather than keep pushing new content to the end of the vector. I have been using 'openfl.utils.Object' to cheat for now but I am looking for a more reliable approach for the long run.
Is there a way to do this in Haxe?
If not, what are my options?
I would also be interested in a solution for this in AS3, if there is one (avoiding the Array class).
My goal is to find a method that I can use in both languages seamlessly (next-to-none, differences).
Vector's cannot be indexed by string in Haxe. A vector is an array with a fixed size. This is the Haxe manual on that subject.
Instead of vectors, you can use a Map.
class Test {
private var vector:Map<String, String> = new Map<String, String>();
public function new() {
var str = 'haxe';
vector[str] = "is great";
trace(vector[str]);
}
static function main() {
new Test();
}
}
https://try.haxe.org/#F74Ba
I think you could do this using flash.utils.Dictionary:
ActionScript
import flash.utils.Dictionary;
...
var _bindingsFiltered:Dictionary = new Dictionary ();
_bindingsFiltered[_controller_touched_binding.action] = "BUTTON_13";
trace(_bindingsFiltered["meta_start"]); //result: "BUTTON_13"
Haxe
import openfl.utils.Dictionary;
...
var _bindingsFiltered = new Dictionary<String, String> ();
_bindingsFiltered[_controller_touched_binding.action] = "BUTTON_13";
trace(_bindingsFiltered["meta_start"]); //result: "BUTTON_13"
First, do you really want an array / vector / list, or do you really want a hashmap of key / value pairs? How are you using the collection? Why do you want String keys? And related, is this mostly about access symantics (you want to type it this way), or are the runtime reasons you'd want to use strings (serialization / etc)?
From what you've described, it sounds like what you really want is an Object like the ones in AS3/JS/ECMAScript, with square-bracket access symantics -- obj[key]
Yes, you can do that in Haxe. The openfl.utils.Object class is a helper to do exactly this, using Dynamic objects and reflection. It should compile to exactly what you want on all Haxe targets.
In any case, if you'd like to feel like you're not bound to OpenFL, no problem. Copy the openfl/utils/Object.hx file and place it anywhere you like in your project's class path (and update the package statement).
There's nothing particularly OpenFL-ish about that code. It's pure Haxe code with no dependencies. It provides array access with String keys, as well as toString, toLocaleString, propertyIsEnumerable, iterator, isPrototypeOf, and hasOwnProperty functions (which ECMA-folk are used to.)
The transition from AS3/JS to Haxe is a little weird, especially when it comes to dynamic objects, and I've been meaning to blog more about it. ;) Good luck!
ETA: In truth, you probably want to get away from Dynamic/Reflection, and embrace a more type-strict approach. AS3/JS devs don't understand this at first, but it is where the benefits of Haxe come from. If you don't then your Haxe experience is likely to be unplesant.
Short answer: yes, you can.
abstract MyVector<T>(Vector<T>) {
public function new(l:Int) this = new Vector<T>(l);
#:op([]) public function set<K:T>(s:String, v:K) {
switch (s) {
case "FIRST": this[0] = v;
case "SECOND": this[1] = v;
default: return;
}
}
#:op([]) public function get(s:String) {
switch (s) {
case "FIRST": return this[0];
case "SECOND": return this[1];
default: return cast 0;
}
}
}
var mv = new MyVector<String>(2);
mv["SECOND"] = "Second";
trace(mv["SECOND"]); // outputs Second
You can inline get and set methods if you want.
Firstly, please forgive any rookie mistakes here - I'm not a regular poster I'm afraid.
Now on to the nitty gritty...
I am trying to use ServiceStack.Text to serialize objects to CSV. If I keep it simple, everything works as expected when serializing objects of a known type.
However I want to serialize many objects and I don't know the type at runtime so I am writing a reusable component where all data is treated as a System.Object. We already do this same routine for Json serialization without problems. But CsvSerializer appears to handle objects differently during serialization.
Sample code
public void TestIEnumerableObjectSerialization()
{
var data = GenerateSampleData();
JsConfig<DateTime>.SerializeFn =
time => new DateTime(time.Ticks, DateTimeKind.Utc).ToString("yyyy-MM-dd HH:mm:ss");
var csv = CsvSerializer.SerializeToCsv(data);
Console.WriteLine(csv);
Assert.Equal("DateTime\r\n"
+ "2017-06-14 00:00:00\r\n"
+ "2017-01-31 01:23:45\r\n",
csv);
}
object[] GenerateSampleData()
{
return new object[] {
new POCO
{
DateTime = new DateTime(2017,6,14)
},
new POCO
{
DateTime = new DateTime(2017,1,31, 01, 23, 45)
}
};
}
public class POCO
{
public DateTime DateTime { get; set; }
}
The result of this code is that the custom serialization function is not invoked, and the DateTime is written out using the standard ToString() method.
The cause?
The CsvWriter.Write method is inspecting the type of the records and if the type is Object it is treated as a Dictionary<string, object> and CsvDictionaryWriter generates the output.
In turn, CsvDictionaryWriter uses the ToCsvField() extension method to write each property a record.
The problem is that ToCsvField() converts the value of each property to a string using ToString() meaning no custom serialization is performed.
JsonSerializer uses TypeSerializer.SerializeToString(text) to serialize the properties of an Object using any configured custom serialization functions; but this doesn't happen with CsvSerializer.
A possible solution?
Without complicating CsvSerializer, the ToCsvField() extension method could be updated to use TypeSerializer to handle the serialization to a string. Here is what I've been testing with so far:
public static object ToCsvField(this object text)
{
var textSerialized = TypeSerializer.SerializeToString(text).StripQuotes();
return textSerialized == null || !CsvWriter.HasAnyEscapeChars(textSerialized)
? textSerialized
: string.Concat
(
CsvConfig.ItemDelimiterString,
textSerialized.Replace(CsvConfig.ItemDelimiterString, CsvConfig.EscapedItemDelimiterString),
CsvConfig.ItemDelimiterString
);
}
So far I haven't come across an issue with this change, although someone may prefer not to allocate a new intermediate variable before the return statement.
Hopefully that is enough information, so on to my questions...
Has anyone else experienced this issue?
Am I doing something wrong and should I be serializing Objects a different way?
If this is a suitable fix/implementation of TypeSerializer, what are the chances of this being addressed in an update to ServiceStack.Text? I would raise an issue on GitHub but the ServiceStack.Text repo doesn't let me raise issues.
Thanks in advance.
I would like to change the way enums are marshalled to JSON. I am currently using default grails.converters.JSON ( as JSON) and for example in controller I use:
FilmKind.values() as JSON
The output of this is:
"kind":[{"enumType":"FilmKind","name":"DRAMA"},{"enumType":"FilmKind","name":"ACTION"}]
I would like to remove "enumType" and just return:
"kind":["DRAMA","ACTION"]
I am looking for a solution which would still allow me to use
as JSON
because I don't want to marshall each enumeration individually.
In case anyone is wandering how to convert all enum values to plain String values in a generic way:
class EnumTypeHidingJSONMarshaller {
void register() {
JSON.registerObjectMarshaller(Enum) { Enum someEnum ->
someEnum.toString()
}
}
}
because I don't want to marshall each enumeration individually.
Well, unless you want to write your own JSON converter, marshalling is the best approach here. Reason is because the only real other way is to do what Sergio is suggesting and you'll have to call that code everywhere you need it. And if FilmKind is a property of another class then his solution won't work at all really.
I would suggest Marshallers and here is how I would do it. Create a class called FilmKindMarsaller:
class FilmKindMarshaller {
void register() {
JSON.registerObjectMarshaller(FilmKind) { FilmKind filmKind ->
[
name: filmKind.toString()
]
}
}
}
Then add the following to your Bootstrap:
[ new FilmKindMarshaller() ].each { it.register() }
The above is so that you can just keep adding instances of each Marshaller you need.
Now, anytime FilmKind is JSON'ified, be that on its own or part of a parent class, you get the JSON you want, sans enumType.
You can register a custom object marshaller for your domain class to allow as JSON. In your Bootstrap.groovy, you can do something like this:
JSON.registerObjectMarshaller(FilmKind) {
def result = [:]
def props = ['name']
props.each { prop ->
result[prop] = it."$prop"
}
result
}
How about:
def display = [kind:[]]
FilmKind.values().each { val ->
display.kind.add(val.value)
}
render display as JSON
I need to encode and Decode AS3 Objects in a typed manner. http://code.google.com/p/as3corelib/ only supports untyped encoding and decoding.
http://code.google.com/p/ason/ supports some kind of typed objects but is not very robust, e.g. it fails on Date Objects. Any Recommendations ?
To make it clear: It MUST be JSON and it MUST be strong typed and robust.
JSON is built in in AS3. The preferred method to transmit data over the wire is AMF, which does provide you typed objects.
If you have to use JSON, then I guess that you might have to do with some sort of custom protocol to be able encode/decode with types.
You would actually need a reflection utility that read beans in JSON format and then produce your object. It really depends on how deep you want to go.
as3Commons has a reflect package that could help. They also have a JSONTypeProvider, which is not exactly what you need but can put you in the right tract.
You could modify any of the IOC frameworks to produce the context by parsing JSON instead of the regular XML most of them use.
You could modify ASON and add a custom type parser. You would have to send a variable in your JSON object containing the type of the object. And use that in with flash.utils.getDefinitionByName.
Another approach would be to just parse the objects with a regular JSON parser and then if it has a defined type create an instance of that objet, and initialize the properties.
Something like this, to get you started:
var beanInfo:Object = JSON.decode( jsonString );
beanInfo = _parseBean( beanInfo );
private function _parseBean(beanInfo:Object):Object{
if ( beanInfo.hasOwnProperty("_type") ) {
var clazz:Class = getDefinitionByName( beanInfo._type ) as Class;
beanInfo.__clazz = clazz;
var instance:Object = new clazz;
for( var prop:String in beanInfo ) {
if( instance.hasOwnProperty(prop) ) target[prop] = _getPropertyFrom(beanInfo[prop]);
}
}
}
private function _getPropertyFrom(property:String):* {
var xml:XML = describeType( beanInfo.__clazz );
//find the type of the current property.
var type:String = xml...
//if is a simple object then do something like
switch( type ) {
case "number":
return parseFloat(property ) as Number;
break;
case "int":
case "uint":
return parseInt( property );
break;
case "string":
return property as String;
break;
...
default
//As it is it does not suppor complex objects.
//You would use reflection. But then you could save the whole switch...
break;
}
}
Flash has its own serialization system.
var serializer:ByteArray = new ByteArray();
serializer.writeObject(new Sprite());
serializer.position = 0;
var data:String = serializer.readUTFBytes(serializer.bytesAvailable);
trace(data); //Will show you the binary jibberish
You can use registerClassAlias to add support for custom classes.
JSON doens't really define a means to convey type information. It's just strings and ints and arrays and so on. So basically you need some sort of "pickle" for AS3 that's based on JSON. I would suggest you look into Flex/Flash remoting solutions and see how they package objects to be transmitted for RPC; you might be able to modify that solution to use JSON. I'm actually doubtful you'll find a library like this. Does it have to be JSON? I'm pretty sure there are XML based libraries that do this.
JSON is not implemented in the flash virtual machine, and therefore there is no typed object "JSON" as there is "Xml." So basically you can decode JSON just fine, but the type you're going to get is Object. You can them access data using the key in the object as an associative array.
http://blog.alien109.com/2009/02/11/php5-json-as3corelib-a-beautiful-thing/
JSON lib/utils official from adobe:
http://code.google.com/p/as3corelib/source/browse/#svn%2Ftrunk%2Fsrc%2Fcom%2Fadobe%2Fserialization%2Fjson
As good as it gets. :)
There are two operations you need to consider: 1) serializing an object of a particular type into JSON and 2) deserializing a JSON string into an object of a particular type.
The serialization part is easy - just use the built-in JSON.stringify(). Deserializing a JSON string into an object of a particular type in ActionScript is where it gets interesting (and where the answer to your question is). You need to write your own deserialization function for the classe(s) you will need to deserialize. In that function, you need to provide a reviver function to JSON.parse(), which allows you to customize how the JSON gets deserialized.
For example:
public static function deserializeComplexObject(json:String):ComplexObject
{
if (null == json || "null" == json)
{
return null;
}
var complexObject:ComplexObject = new ComplexObject();
var parsedObject:Object = JSON.parse(
json,
function (key:String, value:Object):*
{
switch (key)
{
case “keyForNumber”:
return value;
case “keyForComplexObject2”:
return deserializeComplexObject2(JSON.stringify(value));
case “keyForComplexObject3”:
return deserializeComplexObject3(JSON.stringify(value));
case “keyForString”:
return value;
case “keyForBoolean”:
return value;
default:
return value;
}
}
);
complexObject.keyForNumber = parsedObject.keyForNumber;
complexObject.keyForComplexObject2 = parsedObject.keyForComplexObject2;
// continue setting fields
// …
return complexObject;
}
Each case statement corresponds to a top-level key in the JSON string. You don't actually need separate case statements for every key - you can use the default case to handle all keys that map to values that are one of the simple types (Object, Array, String, Number, Boolean, null) by returning the value as-is.
I have now forked the json part of http://code.google.com/p/as3corelib/ and added typed object support...