Maybe this would be useful: https://github.com/r3b/phantomjs

Text output from `js2flash-objret.html` on browser using Gnash with patch #8916:

JavaScript calls Flash: OK, expected object with [a=Hello, b=World], got object with [a=Hello, b=World]

(Screenshot:

You'd see that Object return value and its first-level members are
passed correctly, and the plugin does not crash.

Text output from `js2flash-rtypes.html` (bug #47004 file #36330) on browser using Gnash with patch #8916:

PASSED: Flash should properly register string_call callback
PASSED: Flash should properly register error_call callback
PASSED: Flash should properly register securityerror_call callback
PASSED: Flash should properly register integer_call callback
PASSED: Flash should properly register float_call callback
PASSED: Flash should properly register infinite_call callback
PASSED: Flash should properly register neginfinite_call callback
PASSED: Flash should properly register nan_call callback
PASSED: Flash should properly register boolean_call callback
PASSED: Flash should properly register null_call callback
PASSED: Flash should properly register noret_call callback
PASSED: Flash should properly register undefined_call callback
PASSED: Flash should properly register exception_call callback
PASSED: Flash should properly register array_call callback
PASSED: Flash should properly register object_call callback
PASSED: Flash should properly register object_customstring_call callback
PASSED: Flash should properly register object_customvalue_call callback
PASSED: Flash should properly register function_call callback
PASSED: Flash callback script_call should return a correct type
PASSED: Flash callback script_call should return a correct value
PASSED: Flash callback error_call should return a correct type
PASSED: Flash callback error_call should return a correct value
PASSED: Flash callback securityerror_call should return a correct type
PASSED: Flash callback securityerror_call should return a correct value
PASSED: Flash callback integer_call should return a correct type
PASSED: Flash callback integer_call should return a correct value
PASSED: Flash callback float_call should return a correct type
PASSED: Flash callback float_call should return a correct value
PASSED: Flash callback infinite_call should return a correct type
FAILED: Flash callback infinite_call should return a correct value ("0" != "Infinity")
PASSED: Flash callback neginfinite_call should return a correct type
FAILED: Flash callback neginfinite_call should return a correct value ("0" != "-Infinity")
PASSED: Flash callback nan_call should return a correct type
FAILED: Flash callback nan_call should return a correct value
PASSED: Flash callback boolean_call should return a correct type
PASSED: Flash callback boolean_call should return a correct value
PASSED: Flash callback null_call should return a correct type
PASSED: Flash callback null_call should return a correct value
PASSED: Flash callback noret_call should return a correct type
PASSED: Flash callback noret_call should return a correct value
PASSED: Flash callback undefined_call should return a correct type
PASSED: Flash callback undefined_call should return a correct value
PASSED: Flash callback exception_call should return a correct type
PASSED: Flash callback exception_call should return a correct value
PASSED: Flash callback array_call should return a correct type
FAILED: Flash callback array_call should return an object of Array class
FAILED: Flash callback array_call should return an array with correct size ("undefined" != "9")
PASSED: Flash callback array_call should return an array with correct element 0
PASSED: Flash callback array_call should return an array with correct element 1
PASSED: Flash callback array_call should return an array with correct element 2
PASSED: Flash callback array_call should return an array with correct element 3
PASSED: Flash callback array_call should return an array with correct element 4
PASSED: Flash callback array_call should return an array with correct element 5
PASSED: Flash callback array_call should return an array with correct element 6
PASSED: Flash callback array_call should return an array with correct element 7
PASSED: Flash callback array_call should return an array with correct element 8
PASSED: Flash callback object_call should return a correct type
PASSED: Flash callback object_call should return an object with correct .a member
PASSED: Flash callback object_call should return an object with correct .b member
PASSED: Flash callback object_customstring_call should return a correct type
ERROR: TypeError: can't convert op1 to primitive type

(Screenshot:

You'd see that Object return value, including its first-level members
are passed correctly; elements in Array return value are also passed too,
(but disguised as an associative array with numeric key);
and the plugin does not crash.

Gnash: 0.8.11dev (patched against git c12c3cf 22-Feb-2016) NPAPI
Browser: Iceweasel 10.0.12 (debian)
System: Debian GNU/Linux 7.0 Wheezy i386

This bug should be unblocked as patch #8909 was applied

I have done some trial and error changes on how libgnashplugin allocates NPObject
for returning as Object value from ExternalInterface callback:

• Original code: crashed at garbage collection.
• When got object return value from player, parse it, but then return `null` to browser instead: not crashing.
• Zero-fill entire of new NPObject before use, then proceed normally: crashed at garbage collection.
• Zero-fill entire of new NPObject before use, set dummy NPClass, then proceed normally: crashed at garbage collection.
• Use `NPN_CreateObject()` to create object instead of `NPN_MemAlloc()`, with `NULL` as class and NPP instance: crashed at allocation.
• Use `NPN_CreateObject()` to create object instead of `NPN_MemAlloc()`, with dummy NPClass, and `NULL` NPP instance: crashed at allocation.
• Use `NPN_CreateObject()` to create object instead of `NPN_MemAlloc()`, with dummy NPClass, and real NPP instance: not crashing.
• Call browser's `window.Object()` to create object instead of `NPN_MemAlloc()`: not crashing.

Last approach looks the best: apart from not crashing, `NPN_SetProperty()`
is now working, and JavaScript's `typeof()` also returns "object"
(instead of just "function"), first-level Object members are also
get passed to JavaScript properly too.

In case anyone want to test the last approach, see the attached `plugin-return-js-object.patch`.

Warning: This patch is experimental; it does work, but it breaks
libgnashplugin's automated test (compile error) as it hacked other parts of
plugin in order to pass `NPP` structure around, and it blatantly removed the
string conversion code which caused bug #47004 (otherwise it will crash).

Bug #47004 (at least on JavaScript-calls-Flash direction) would need to be
fixed in proper way before a fix for this issue could be carried out.

Gnash: 0.8.11dev (patched against git e705394 29-Jan-2016) NPAPI
Browser: Iceweasel 10.0.12 (debian)
System: Debian GNU/Linux 7.0 Wheezy i386

P.S. Removing the string conversion code mentioned in bug #47004
alone won't fix the crash in browser's garbage collection.


(file #36232)

According to current code, it seems that libgnashplugin has limited support
for nested XML value sent from Gnash (player); it supported array and object
with primitive-typed elements/members; if there's a nested array/object,
current parsing code would not find the corresponding end tag properly.

Gnash: 0.8.11dev (git e705394 29-Jan-2016) NPAPI
Iceweasel: 10.0.12 (debian)
System: Debian GNU/Linux 7.0 Wheezy i386

I also made a test Flash file for checking current ExternalInterface's
support for Array-typed callback argument and return type too (in JavaScript
calls Flash direction); attached as `js2flash-arr.zip`.

Screenshot, logs (verbosity 2 + action error), and relevant GDB backtrace
are also included in the same ZIP file.

Array-Typed Function Argument Case

This is an image result from `js2flash-arrarg.html` under browser with Flash Player:
http://i.imgur.com/1BcnPEL.png

Flash Player's trace output from the run:

Warning: Reference to undeclared variable, 'JS2FlashArrayArg'
callee: starting
callee: adding ExternalInterface callback
callee: finished initializing
callee: entering ExternalInterface callback
callee: ExternalInterface callback succeeded, expected array with 2 elements [Hello, World], got array with 2 elements [Hello, World]
callee: ExternalInterface callback finished

You'll see that Flash Player passed an ExternalInterface callback's Array argument, length, and its elements correctly.

This is an image result from `js2flash-arrarg.html` under browser with Gnash:
http://i.imgur.com/7YY6GdA.png

Gnash's console output shows:

SECURITY: Extensions disabled
ACTIONSCRIPT ERROR: reference to non-existent variable 'JS2FlashArrayArg'
TRACE: callee: starting
TRACE: callee: adding ExternalInterface callback
TRACE: callee: finished initializing
TRACE: callee: entering ExternalInterface callback
ACTIONSCRIPT ERROR: getMember called against a value that does not cast to an as_object: [undefined]
ACTIONSCRIPT ERROR: getMember called against a value that does not cast to an as_object: [undefined]
ACTIONSCRIPT ERROR: getMember called against a value that does not cast to an as_object: [undefined]
TRACE: callee: ExternalInterface called incorrectly, expected array with 2 elements [Hello, World] got undefined with undefined elements [undefined, undefined]
TRACE: callee: ExternalInterface callback finished

You'll see from console output that Gnash passed an Array-typed ExternalInterface callback argument as `undefined`.

According to Gnash's container-player communication log, the problem also
started from libgnashplugin sending an empty `<object>` tag to player,
which is incorrect since this array is supposed to have two elements.

Gnash: 0.8.11dev (git 62cfdfe 16-Jan-2016) NPAPI
Flash Player: 11.2.202.491 NPAPI binary
Iceweasel: 10.0.12 (debian)
System: Debian GNU/Linux 7.0 Wheezy i386

(file #36190)

From test results and communication logs, it looks like that nested XML tags
parsing is needed on both side to support Object-typed (and Array-typed)
argument and return value in ExternalInterface like Adobe Flash Player do.

Note: There might be some corner cases on how to deal with looped or
duplicated Object references, but it would take some more testing to see
how Adobe Flash manages (or discards) it.

This is a follow up from bug #37223 comment 4.

I have created dummy SWF files to minimally demonstrate the need for this
functionality. One of SWF file receives an Object argument from JavaScript,
another one tries to pass Object return value to JavaScript.

The Object passed is just a simple Object created from `new Object()`
statement (from both language), then assigned a member named `a` with string
value "Hello", and assigned a member named `b` with string value "World".

Object-Typed Function Argument Case

This is an image result from `js2flash-objarg.html` under browser with Flash Player:
http://i.imgur.com/cfDCgOi.png

Flash Player's trace output from the run:

Warning: Reference to undeclared variable, 'JS2FlashObjectArg'
callee: starting
callee: adding ExternalInterface callback
callee: finished initializing
callee: entering ExternalInterface callback
callee: ExternalInterface callback succeeded, expected object with member [a=Hello, b=World] got object with [a=Hello, b=World]
callee: ExternalInterface callback finished

You'll see that Flash Player passed an ExternalInterface callback's Object argument and its members correctly.

This is an image result from `js2flash-objarg.html` under browser with Gnash:
http://i.imgur.com/rNCDxOu.png

Gnash's console output shows:

76 SECURITY: Extensions disabled
76 ACTIONSCRIPT ERROR: reference to non-existent variable 'JS2FlashObjectArg'
76 TRACE: callee: starting
77 TRACE: callee: adding ExternalInterface callback
77 TRACE: callee: finished initializing
2939 TRACE: callee: entering ExternalInterface callback
2939 ACTIONSCRIPT ERROR: getMember called against a value that does not cast to an as_object: [undefined]
2939 ACTIONSCRIPT ERROR: getMember called against a value that does not cast to an as_object: [undefined]
2939 TRACE: callee: ExternalInterface called incorrectly, expected object with member [a=Hello, b=World] got undefined with [a=undefined, b=undefined]
2939 TRACE: callee: ExternalInterface callback finished

Apart from hairline stroke issue (bug #45731), you'll see from console output
that Gnash passed an Object-typed ExternalInterface callback argument as `undefined`.

According to Gnash's container-player communication log, the problem started
from libgnashplugin sending an empty `<object>` tag to player, which is
incorrect since this object is supposed to have two member.

Gnash: 0.8.11dev (git 15d61a8 26-Dec-2015) NPAPI
Flash Player: 11.2.202.491 NPAPI binary
Browser: Iceweasel 10.0.12 (debian)
System: Debian GNU/Linux 7.0 Wheezy

The plugin shouldn't be using any headers from Gnash core. I see only StringPredicates.h and GnashSystemIOHeaders.h, which I guess are safe. AS3 did add more functionality to the API. But the point is I don't believe ExternalInterface is supposed to ever handle nested tags, so this bug report could be bogus, and based on a broken test case.

Currently the plugin uses no headers from the rest of gnash. The debug functions are actually different, just have the same names.
Sharing header only code for XML parsing is fine, it just isn't a big saving in code. You're welcome to implement such a thing if you want, but as ExternalInterface is currently working fine with the new YouTube API, it seems there are more important things to be working on. Maybe it's time for somebody to start on a real plugin. Adobe uses ExternalInterface for the flash debugger, which is the entire reason it's an XML networking protocol.

EsxternalInterface doesn't pass JavaScript at all, only the XML messages as specified by the Adobe spec. Even with a traditional style plugin, we'd still want the optional ability to use a network to remotely control Gnash when running standalone. I don't think ExternalInterface is supposed to deal with nested tags, the test case could be trying to test functionality that may never been required. Before talking about how ExternalInterface works, it'd be easier if people actually researched this first.

The plugin shouldn't have any dependencies on core Gnash code unless we ever create a traditional style plugin. While it might be possible to use XML_as.cpp on the Gnash side, the XML used for the ExternalInterface messages in the plugin is much simpler, and deals with NPVariants, instead of ActionScript objects.

It's plugin/npapi/test.cpp. There are two sets of files required for EsternalInterface to work, the plugin side in plugin/npapi, and the Gnash side in libcore.

As shown by test.c, the parseArguments function fails when one of the arguments is an object (ie: contains sub-elements)