expose custome object or function to script environement

[A. Sundararajan]

You could use any of the following options:

1) Write a Java object with bean-style getters and getters - which can 
be used by scripts 'as is'. This is the most direct and simple way. 
Users can use "new" to create objects and use "obj.prop" to access/write 
to bean-properties and call public Java methods. If there are 'event' 
callback methods accepting interfaces, scripts can pass a script 
implementation of interfaces or just pass a script function if the 
interface is a SAM interface.

2) You could implement jdk.nashorn.api.scripting.JSObject interface in  
your class and expose the objects of the same. You could it make your 
object behave like function by implementing call and newObject methods. 
And implement getMember and putMember methods to expose properties to 
scripts.

3) You could have a script object whose properties are bound to a Java 
object. Example:

     var obj = {};
     Object.bindProperties(obj, myJavaObject);
     print(obj.foo); // calls myJavaObject.getFoo() bean getter

The above 'binds' bean-style properties of your Java object to the 
script object "obj". The script object could have usual proto and so 
on.  This flexible option allows your script object to behave as normal 
script object -- but some properties being implemented in Java.

All these are documented in

https://wiki.openjdk.java.net/display/Nashorn/Nashorn+jsr223+engine+notes
https://wiki.openjdk.java.net/display/Nashorn/Nashorn+extensions

-Sundar

On Monday 13 January 2014 03:19 PM, buddhi mihara wrote:
> hi,
> i am writing a server side js language just like node.jswhat is the proper way to expose custom object just like NativeMath or custom constructor function just like Native Date to the script environment
> thank you