Hi Vassilis,
I have been using JsInterop for managing IndexedDB stores and I have created 
this [1] helper class for casting back and forth js to java. The main issue is 
that in GWT there are two Object hiearchies
one from java and js, GWT makes are really job hiding that detail, but with 
JsInterop the difference leaks ;-)

[1] 
https://github.com/bauna/gwt-indexeddb/blob/devel/gwt-indexeddb-core/src/main/java/org/nuvola/indexeddb/client/JsInteropHelper.java

Let me know if want examples where I'm using this helper class.

Regards,
-- 
Pablo

On 12/05/16 07:43, Vassilis Virvilis wrote:
> Thanks for all the answers
>
> The Collection#toArray does not work in my case because dataTables.net are a 
> bit sensitive in the input. It stumbles upon java.lang stuff later on.
> Here
>
>         buttons = new String[] {"copyHtml5"};
>
> while buttons2 is the correct one created with your previous suggestion.
>
>  1. buttons:
>      1. 0:"copyHtml5"
>      2. __elementTypeCategory$:6
>      3. __elementTypeId$:2
>      4. java_lang_Object__1_1_1clazz:java_lang_Class_Class__V
>      5. java_lang_Object_castableTypeMap:Object
>      6. 
> java_lang_Object_typeMarker:com_google_gwt_lang_Runtime_typeMarkerFn__V()
>      7. length:1
>      8. __proto__:Array[0]
>  2. buttons2:Array[1]
>      1. 0:"copyHtml5"
>      2. length:1
>      3. __proto__:Array[0]
>
> About Array vs []
> I am not js expert and looking for the difference I hit this 
> http://stackoverflow.com/questions/931872/what-s-the-difference-between-array-and-while-declaring-a-javascript-ar
> Check this answer 
> http://stackoverflow.com/questions/931872/what-s-the-difference-between-array-and-while-declaring-a-javascript-ar/1273936#1273936
>
> So I though if that could work with GWT and I tried it.
>
> Also thanks for the link I bookmarked it.
>
>
> On Thu, May 12, 2016 at 1:20 PM, Thomas Broyer <t.bro...@gmail.com 
> <mailto:t.bro...@gmail.com>> wrote:
>
>
>
>     On Thursday, May 12, 2016 at 11:51:11 AM UTC+2, Vassilis Virvilis wrote:
>
>         Thomas thanks,
>
>         Wow I did this and it works. But it is crazy. Cr is for crazy. Kudos 
> to jsinterop guys though.
>
>             @JsType(isNative = true, namespace = JsPackage.GLOBAL, name = 
> "[]")
>
>
>     You should probably use "Array" rather than "[]"
>      
>
>             public interface CrJsArray<T> {
>
>                 public void push(T value);
>
>                 @JsProperty
>                 public int getLength();
>             }
>
>
>         I tried your suggestion to cast and __also works__ (eclipse complains 
> about but with (JavaScriptObject) (Object) my_native_object) it works and it 
> is definitely better.
>
>
>     Also, for converting from a java.util.Collection to an array, how about 
> simply using Collection#toArray? (and then passing the array to JS through 
> JsInterop)
>      
>
>         Questions
>         1) Is JavaScriptObject scheduled for deprecation?
>
>
>     Yes, it'll be replaced with JsInterop.
>      
>
>         2) Should a native type be able to extend JavascriptObject. Because 
> right now (2.8pre1) fails at run time. That would make casting a bit saner. 
> Should I report it somewhere?
>
>
>     This is probably on-purpose.
>      
>
>         I tried to look for the reference you gave but I didn't find it. 
> Wrong keywords maybe...
>
>
>     I found this: 
> https://groups.google.com/d/topic/google-web-toolkit/nmBAOX4vcSo/discussion
>     Not exactly what I remembered, but touches similar points.
>      
>
>
>         On Thu, May 12, 2016 at 12:20 PM, Thomas Broyer <t.bro...@gmail.com 
> <mailto:t.bro...@gmail.com>> wrote:
>
>             That question came up already in the forum or in GWT-Contrib (try 
> to search the archive), and I seem to recall that Goktug said you could cast 
> @JsType(isNative=true) objects to/from
>             JavaScriptObject, so you could use JsArray (and 
> JsonUtils.safeEval). I think you can also cast to/from an array of 
> @JsType(isNative=true), so if you don't need to alter the size of the
>             JS array you can then use the bracket operators on a Java array 
> (and cast from/to a JavaScriptObject).
>             This is only out of memory, please double check from the forum 
> archives.
>
>
>             On Thursday, May 12, 2016 at 10:47:51 AM UTC+2, Vassilis Virvilis 
> wrote:
>
>                 Hi again,
>
>                 I am trying to convert a jre collection or build a jsArray 
> with a isNative=true type.
>
>                 Unfortunately this is not possible because JsArray requires 
> JavascriptObject which is invcompatible (complie time error) with native 
> classes.
>
>                 Any ideas?
>
>                 I looked on deep dive jsinterop from Ray Cromwell and it says 
> that there is not a clean way for jsinterop1 to align collections. Ok I get 
> that - but there must be a way even if not
>                 the nicest/cleanest one.
>
>                 Otherwise looks like I have to create my own @jsinteroped 
> MyJsArray which looks wrong.
>
>                 -- 
>                 Vassilis Virvilis
>
>             -- 
>             You received this message because you are subscribed to the 
> Google Groups "GWT Users" group.
>             To unsubscribe from this group and stop receiving emails from it, 
> send an email to google-web-toolkit+unsubscr...@googlegroups.com 
> <mailto:google-web-toolkit+unsubscr...@googlegroups.com>.
>             To post to this group, send email to 
> google-web-toolkit@googlegroups.com 
> <mailto:google-web-toolkit@googlegroups.com>.
>             Visit this group at 
> https://groups.google.com/group/google-web-toolkit.
>             For more options, visit https://groups.google.com/d/optout.
>
>
>
>
>         -- 
>         Vassilis Virvilis
>
>     -- 
>     You received this message because you are subscribed to the Google Groups 
> "GWT Users" group.
>     To unsubscribe from this group and stop receiving emails from it, send an 
> email to google-web-toolkit+unsubscr...@googlegroups.com 
> <mailto:google-web-toolkit+unsubscr...@googlegroups.com>.
>     To post to this group, send email to google-web-toolkit@googlegroups.com 
> <mailto:google-web-toolkit@googlegroups.com>.
>     Visit this group at https://groups.google.com/group/google-web-toolkit.
>     For more options, visit https://groups.google.com/d/optout.
>
>
>
>
> -- 
> Vassilis Virvilis
> -- 
> You received this message because you are subscribed to the Google Groups 
> "GWT Users" group.
> To unsubscribe from this group and stop receiving emails from it, send an 
> email to google-web-toolkit+unsubscr...@googlegroups.com 
> <mailto:google-web-toolkit+unsubscr...@googlegroups.com>.
> To post to this group, send email to google-web-toolkit@googlegroups.com 
> <mailto:google-web-toolkit@googlegroups.com>.
> Visit this group at https://groups.google.com/group/google-web-toolkit.
> For more options, visit https://groups.google.com/d/optout.

-- 
You received this message because you are subscribed to the Google Groups "GWT 
Users" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to google-web-toolkit+unsubscr...@googlegroups.com.
To post to this group, send email to google-web-toolkit@googlegroups.com.
Visit this group at https://groups.google.com/group/google-web-toolkit.
For more options, visit https://groups.google.com/d/optout.

Reply via email to