Map should support hasOwnProperty?

[Hannes Wallnöfer]

Hi Jörg, 

We have currently no plans to make Object.prototype.hasOwnProperty on non-JavaScript objects. However, I recently pushed a change that makes the in-operator work with Java objects, maps, lists, and arrays to JDK 9.

https://bugs.openjdk.java.net/browse/JDK-8173480

Hannes

> Am 02.02.2017 um 16:28 schrieb Frantzius, Jörg <Joerg.Frantzius at aperto.com>:
> 
> Hi,
> 
> Nashorn’s extensions let Java Map objects behave somewhat like Javascript objects by making its key-values accessible as object properties.
> 
> Unfortunately, it seems that hasOwnProperty() is commonly used in Javascript code to iterate the properties of an object, and this doesn’t work on Map objects. Maybe it would be a good idea to also support hasOwnProperty() on Map objects?
> 
> Currently it seems impossible to let 3d party Javascript code traverse a a Java object graph with nested Map objects. While I may be able to traverse and convert a Java object graph if it is made from Collections, Arrays and Maps, this will fail as soon as there is a custom Java class involved that has a Map field (that is accessed from Javascript).
> 
> Thanks for any thoughts,
> Jörg
> 
> 
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