On Mar 2, 6:51 pm, Norris Boyd <[email protected]> wrote:
> On Feb 25, 1:51 pm, Greg Lindholm <[email protected]> wrote:
>
>
>
> > On Feb 25, 11:18 am, wolffiex <[email protected]> wrote:
>
> > > On Feb 24, 8:35 am, Greg Lindholm <[email protected]> wrote:
>
> > > > Using Rhino 1.7R1
>
> > > > I'm running JS from a Java web application and have setup a Sealed
> > > > shared scope as described herehttp://www.mozilla.org/rhino/scopes.html.
>
> > > > For each "request" where I need to run JS I setup a new scope and
> > > > point the prototype to the sealedSharedScope.
>
> > > > I have found that if I seal the shared scope itself
> > > > ( sealedSharedScope.sealObject(); ) then I get this exception when I
> > > > attempt to use Java classes from within a script.
>
> > > > org.mozilla.javascript.EvaluatorException: Cannot modify a property of
> > > > a sealed object: getClass. (/initSharedScope.js#44)
>
> > > > I have traced the root cause down to inside:
> > > > org.mozilla.javascript.NativeJavaTopPackage.init(Context cx,
> > > > Scriptable scope, boolean sealed)
>
> > > > Inside the init() method this call is made which attempts to define a
> > > > property in the parent scope for the function "getClass".
> > > > getClass.exportAsScopeProperty(); // line 139
>
> > > > It then throws the exception because the scope has been sealed.
>
> > > > If I don't call sealedSharedScope.sealObject(); then everything works
> > > > with no exception. But of course the scope isn't sealed and this is
> > > > too dangerous for untrusted JS in a shared environment.
>
> > > > I've tried adding the "dynamic scope" but this made no difference.
>
> > > > It appears that using a Sealed Shared Scope and Java classes is
> > > > incompatible. Is there some way to make this work?
>
> > > > Note if you test this with some common java classes like
> > > > "java.lang.String" it works fine as it appears some common classes are
> > > > predefined in the scope or pre-cached.
> > > > Note I also use a ClassShutter to limit the java classes allowed to
> > > > safe classes.
>
> > > I believe this is a bug that is actually fixed in the latest release
> > > candidate regarding the lazy loading of certain Rhino properties. I'm
> > > still on an older release, though, so my sealed scope initializer
> > > looks like this:
>
> > > topLevel = cx.initStandardObjects(null, true);
> > > //Force all the stuff we need to be loaded. These objects
> > > are meant to be lazy
> > > //loaded by Rhino but that doesn't work since the scope is
> > > sealed.
> > > String loadMe = "RegExp; getClass; java; Packages;
> > > JavaAdapter;";
> > > cx.evaluateString(topLevel, loadMe, "lazyLoad", 0, null);
> > > topLevel.sealObject();
>
> > > Just by mentioning the properties in the loadMe string, Rhino puts
> > > these in the scope before it is sealed. Obviously if you need other
> > > features like E4X, you could mention those in the loadMe string too.
>
> > > HTH,
> > > A
>
> > Thanks a lot, that did the trick.
>
> > Maybe someone with access can put a note about this in the discussion
> > about scopes on this pagehttp://www.mozilla.org/rhino/scopes.htmlas
> > it would have saved me a lot of time and frustration.
>
> I've moved the content over to the MDC
> wiki:https://developer.mozilla.org/En/Rhino_documentation/Scopes_and_Contexts
>
> Can you modify with your change?
>
> Thanks,
> Norris
Yes, I've added this note to the end of the Sealed Shared Scope
section:
Note that currently in order to use Java classes (LiveConnect) from a
sealed shared scope you need to pre-load a number of objects needed
for LiveConnect into the scope before it gets sealed. These objects
would normally be lazy loaded but the lazy loading fails if the scope
is sealed.
ScriptableObject sealedSharedScope = cx.initStandardObjects(null,
true);
// Force the LiveConnect stuff to be loaded.
String loadMe = "RegExp; getClass; java; Packages; JavaAdapter;";
cx.evaluateString(sealedSharedScope , loadMe, "lazyLoad", 0,
null);
sealedSharedScope .sealObject();
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