Passing map as a function parameter

[Viktor Remennik]

Hi there,

I am a new user looking for nashorn alternatives. In nashorn I use Map to pass an object as a foo parameter. How can I dynamically construct a JS object and pass it to my foo with Rhino?

Thank you 

[Michael Bar-sinai]

You can use the Context.javaToJS, like so:

Scriptable programScope = ...

try {

   Context.enter();

   programScope.put(name, programScope, Context.javaToJS(obj, programScope));

} finally {

   Context.exit();

[Viktor Remennik]

But I need to dynamically create JS object. In Nashorn I could use a Map which automatically will be converted to the JS object, i. e. if I put in map "key1","val1" and "key2","val2", and then put this map to the context, it will be available in JS like

{

   key1: "val1",

   key2: "val2"

[Michael Bar-sinai]

To dynamically create a JS object, you can use ScriptableObject and put it in the JS program scope. 

[Viktor Remennik]

I understand that, but do not know how! )

[Michael Bar-sinai]

Something along these lines:

Java

-------

final ScriptableObject spMap = new NativeMap();

Map<String,Object> javaMap = Map.of("a",10,"b",20,"c",35,"dee",500, "last","I'm the last key!");

javaMap.forEach( (a,b)->spMap.put(a, spMap, b) );

try {

  Context.enter();

 YOUR_PROGRAM_GLOBAL_SCOPE.put("dynMap", YOUR_PROGRAM_GLOBAL_SCOPE, Context.javaToJS(javaMap, YOUR_PROGRAM_GLOBAL_SCOPE));

} finally {

   Context.exit();

}

Javascript (bp.log.info is a logger, think of it as println() or console.log )

--------------

if ( dynMap ) {

    for ( let d in dynMap ) {

        bp.log.info( d + ": " + dynMap[d] );

    }

}

Result

---------

[BP][Info] b: 20

[BP][Info] c: 35

[BP][Info] dee: 500

[BP][Info] last: I'm the last key!

[BP][Info] a: 10

You can try to remove the call to Context.javaToJS and just place the object in the scope, since it's a native object. Also, there may be better ways of doing this.... but this works.