Cool. Any examples out there in the ether? That said, I do think an interface-based approach would be more desirable since it does not force a specific class hierarchy (e.g. must extend JSObject), which could be very problematic in many cases (including ours).
-----Original Message----- From: Attila Szegedi [mailto:attila.szeg...@oracle.com] Sent: Tuesday, October 22, 2013 12:51 PM To: Rick Bullotta Cc: A. Sundararajan; nashorn-dev@openjdk.java.net Subject: Re: Docs/examples for JSAdapter You should be able to use your own subclasses of jdk.nashorn.api.scripting.JSObject for this purpose. Attila. On Oct 22, 2013, at 6:46 PM, Rick Bullotta <rick.bullo...@thingworx.com> wrote: > Yuck. Looks like we'll be sticking with Rhino for a while then. > > I would STRONGLY recommend adding the ability of a Java class developer to > implement an interface that provides the functionality I described in my > response to Jim. It is just plain wrong to push complexity to the end user > when it can easily be solved in the framework/platform. To implement that > should be rather trivial, to be honest. > > > -----Original Message----- > From: nashorn-dev-boun...@openjdk.java.net > [mailto:nashorn-dev-boun...@openjdk.java.net] On Behalf Of A. Sundararajan > Sent: Tuesday, October 22, 2013 12:33 PM > To: nashorn-dev@openjdk.java.net > Subject: Re: Docs/examples for JSAdapter > > No. Nashorn uses wrapperless Java objects. Java objects are exposed to > scripts "as is" - no wrapping as 'script objects' as in Rhino. > > It is possible to implement Java interfaces in script (just like it was in > Rhino). > > -Sundar > > On Tuesday 22 October 2013 09:32 PM, Rick Bullotta wrote: >> In Rhino, you register custom adapters in a "wrap factory" that tells the >> script engine to use these adapters for accessing instances of those >> classes/types. What's the analog in Nashorn? Can custom types implement >> interfaces that Nashorn will use? >> >> From: Jim Laskey (Oracle) [mailto:james.las...@oracle.com] >> Sent: Tuesday, October 22, 2013 11:52 AM >> To: Rick Bullotta >> Cc: nashorn-dev@openjdk.java.net >> Subject: Re: Docs/examples for JSAdapter >> >> In general the Nashorn docs start here. >> https://wiki.openjdk.java.net/display/Nashorn/Nashorn+Documentation, but as >> you point out, we seem to be lacking JSAdapter details. I should start an >> FAQ. >> >>> From the javadoc (cd make; ant javadoc # ./dist/javadoc/index.html) >> >> >> * public final class NativeJSAdapter >> >> * extends >> ScriptObject<file:///\\Volumes\Elephant\Projects\nashorn~jdk8\nashorn\dist\javadoc\jdk\nashorn\internal\runtime\ScriptObject.html> >> This class is the implementation of the Nashorn-specific global object named >> JSAdapter. It can be thought of as the >> Proxy<http://docs.oracle.com/javase/7/docs/api/java/lang/reflect/Proxy.html?is-external=true> >> equivalent for JavaScript. NativeJSAdapter calls specially named JavaScript >> methods on an adaptee object when property access/update/call/new/delete is >> attempted on it. Example: >> >> var y = { >> >> __get__ : function (name) { ... } >> >> __has__ : function (name) { ... } >> >> __put__ : function (name, value) {...} >> >> __call__ : function (name, arg1, arg2) {...} >> >> __new__ : function (arg1, arg2) {...} >> >> __delete__ : function (name) { ... } >> >> __getIds__ : function () { ... } >> >> }; >> >> >> >> var x = new JSAdapter(y); >> >> >> >> x.i; // calls y.__get__ >> >> x.foo(); // calls y.__call__ >> >> new x(); // calls y.__new__ >> >> i in x; // calls y.__has__ >> >> x.p = 10; // calls y.__put__ >> >> delete x.p; // calls y.__delete__ >> >> for (i in x) { print(i); } // calls y.__getIds__ >> >> >> >> JavaScript caller of adapter object is isolated from the fact that the >> property access/mutation/deletion are really calls to JavaScript methods on >> adaptee. >> >> JSAdapter constructor can optionally receive an "overrides" object. >> Properties of overrides object is copied to JSAdapter instance. When user >> accessed property is one of these, then adaptee's methods like __get__, >> __put__ etc. are not called for those. This can be used to make certain >> "preferred" properties that can be accessed in the usual/faster way avoiding >> proxy mechanism. Example: >> >> var x = new JSAdapter({ foo: 444, bar: 6546 }) { >> >> __get__: function(name) { return name; } >> >> }; >> >> >> >> x.foo; // 444 directly retrieved without __get__ call >> >> x.bar = 'hello'; // "bar" directly set without __put__ call >> >> x.prop // calls __get__("prop") as 'prop' is not overridden >> >> >> It is possible to pass a specific prototype for JSAdapter instance by >> passing three arguments to JSAdapter constructor. So exact signature of >> JSAdapter constructor is as follows: >> >> JSAdapter([proto], [overrides], adaptee); >> >> >> Both proto and overrides are optional - but adaptee is not. When proto is >> not passed JSAdapter.prototype is used. >> * >> As well as the test ./test/script/basic/jsadapter.js >> >> var obj = new JSAdapter() { >> __get__: function(name) { >> print("getter called for '" + name + "'"); return name; >> }, >> >> __put__: function(name, value) { >> print("setter called for '" + name + "' with " + value); >> }, >> >> __call__: function(name, arg1, arg2) { >> print("method '" + name + "' called with " + arg1 + ", " + arg2); >> }, >> >> __new__: function(arg1, arg2) { >> print("new with " + arg1 + ", " + arg2); >> }, >> >> __getIds__: function() { >> print("__getIds__ called"); >> return [ "foo", "bar" ]; >> }, >> >> __getValues__: function() { >> print("__getValues__ called"); >> return [ "fooval", "barval" ]; >> }, >> >> __has__: function(name) { >> print("__has__ called with '" + name + "'"); >> return name == "js"; >> }, >> >> __delete__: function(name) { >> print("__delete__ called with '" + name + "'"); >> return true; >> } >> }; >> >> // calls __get__ >> print(obj.foo); >> >> // calls __put__ >> obj.foo = 33; >> >> // calls __call__ >> obj.func("hello", "world"); >> >> // calls __new__ >> new obj("hey!", "it works!"); >> >> for (i in obj) { >> print(i); >> } >> >> for each (i in obj) { >> print(i); >> } >> >> var x = "foo" in obj; >> print(x); >> >> var y = "js" in obj; >> print(y); >> >> print(delete obj.prop); >> >> print(obj["js"]); >> obj["js"] = "javascript"; >> print(obj["javascript"]); >> Hope that helps. Is there a specific question? >> >> Cheers, >> >> -- Jim >> >> On 2013-10-22, at 11:50 AM, Rick Bullotta >> <rick.bullo...@thingworx.com<mailto:rick.bullo...@thingworx.com>> wrote: >> >> >> Hi, all. >> >> I've been searching everywhere for any form of documentation or substantive >> examples as to how JSAdapter works in Nashorn, as it is an essential piece >> of the puzzle for many of us who will naturally be migrating from Rhino. >> >> Can anyone provide and additional info? >> >> Thanks, >> >> Rick >> ThingWorx >> >
