ActiveXObject("htmlfile") and Jscript.NET

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Eugene Gershnik - 09 Oct 2005 18:32 GMT

Consider the following code

var doc = new ActiveXObject("htmlfile");
doc.write("abc");

When executed under WSH this code runs without problems. However, compiling
as

jsc.exe /fast-

and running it produces

Unhandled Exception: System.Runtime.InteropServices.COMException
(0x80020005): T
ype mismatch.

at System.RuntimeType.ForwardCallToInvokeMember(String memberName,
BindingFla
gs flags, Object target, Int32[] aWrapperTypes, MessageData& msgData)
at mshtml.HTMLDocumentClass.write(Object[] psarray)
at invoker0.Invoke(Object , Object[] )
at Microsoft.JScript.JSMethodInfo.Invoke(Object obj, BindingFlags
options, Bi
nder binder, Object[] parameters, CultureInfo culture)
at Microsoft.JScript.LateBinding.CallOneOfTheMembers(MemberInfo[]
members, Ob
ject[] arguments, Boolean construct, Object thisob, Binder binder,
CultureInfo c
ulture, String[] namedParameters, VsaEngine engine)
at Microsoft.JScript.LateBinding.Call(Binder binder, Object[] arguments,
Para
meterModifier[] modifiers, CultureInfo culture, String[] namedParameters,
Boolea
n construct, Boolean brackets, VsaEngine engine)
at Microsoft.JScript.LateBinding.Call(Object[] arguments, Boolean
construct,
Boolean brackets, VsaEngine engine)
at JScript 0.Global Code()
at JScript Main.Main(String[] )

Any idea of what is wrong here and how to fix it?

Signature

Eugene

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Serge Baltic - 12 Oct 2005 12:17 GMT

Hello,

EG> Consider the following code
EG>
EG> var doc = new ActiveXObject("htmlfile");
EG> doc.write("abc");
EG> When executed under WSH this code runs without problems. However,
EG> compiling as
EG>
EG> jsc.exe /fast-

What's the IDL prototype of doc.write?

(H) Serg

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Eugene Gershnik - 12 Oct 2005 19:15 GMT

> Hello,
>
[quoted text clipped - 8 lines]
>
> What's the IDL prototype of doc.write?

"htmlfile" is an MS component.
Friendly name: HTML Document
CLSID: {25336920-03F9-11CF-8FD0-00AA00686F13}
InProcServer32: %SystemRoot%\System32\mshtml.dll

Opening its type library in OleView gives this prototype for write under
dispinterface IHTMLDocument2

[id(0x0000041e), vararg]
void write([in] SAFEARRAY(VARIANT) psarray);

This method is also documented in
http://msdn.microsoft.com/library/default.asp?url=/workshop/browser/mshtml/refer
ence/ifaces/document2/write.asp

Additionally there is some interesting stuff in this component registry
entry under InProcServer32. This is something that that I haven't seen
before

Assembly REG_SZ Microsoft.mshtml, Version=7.0.3300.0, Culture=neutral,
PublicKeyToken=b03f5f7f11d50a3a
Class REG_SZ mshtml.HTMLDocumentClass
RuntimeVersion REG_SZ v1.0.3705
ThreadingModel REG_SZ Apartment

It looks like .NET installed some replacement assembly that wraps this
component and doesn't quite work right.

--
Eugene

Reply to this Message

Serge Baltic - 13 Oct 2005 10:48 GMT

Hello,

>> Hello,
>> What's the IDL prototype of doc.write?

EG> void write([in] SAFEARRAY(VARIANT) psarray);

So why not pass an array of objects, if it accepts an array?

(H) Serge

Reply to this Message

Serge Baltic - 13 Oct 2005 10:53 GMT

Hello,

EG> Additionally there is some interesting stuff in this component
EG> registry entry under InProcServer32. This is something that that I
EG> haven't seen before
EG>
EG> Assembly REG_SZ Microsoft.mshtml, Version=7.0.3300.0,
EG> Culture=neutral,
EG> PublicKeyToken=b03f5f7f11d50a3a
EG> Class REG_SZ mshtml.HTMLDocumentClass
EG> RuntimeVersion REG_SZ v1.0.3705
EG> ThreadingModel REG_SZ Apartment
EG> It looks like .NET installed some replacement assembly that wraps
EG> this component and doesn't quite work right.

Maybe you just don't quite call it right? ;-)

Looking at the write function prototype in the interop assembly I can see
that:

.method public hidebysig newslot virtual instance void write([in] object[]
marshal() psarray) runtime managed internalcall
{
.custom instance void [mscorlib]System.Runtime.InteropServices.PreserveSigAttribute::.ctor()
.custom instance void [mscorlib]System.Runtime.InteropServices.DispIdAttribute::.ctor(int32)
= ( int32(0x0000041E) )
.override mshtml.DispHTMLDocument::write
}

So, it's doc.write(["abc"]) in JScript, I guess; at least, it's definitely
doc.write(new Object[]{"abc"}) in C#.

(H) Serge

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Eugene Gershnik - 13 Oct 2005 17:34 GMT

>> void write([in] SAFEARRAY(VARIANT) psarray);

>So why not pass an array of objects, if it accepts an array?

You missed [vararg] in the function declaration. This is simply an IDL way
of saying that it has variable number of arguments. JScript supports these
natively.

> Maybe you just don't quite call it right? ;-)

Wel it was write("abc") since the beginning of time ;-) This method is one
of the most frequently used in ASP programming; just google for
document.write

In any case I tried your suggestion

var doc = new ActiveXObject("htmlfile");
doc.write(["abc"]);

and got exactly the same error as before.

Signature

Eugene
http://www.gershnik.com

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Serge Baltic - 17 Oct 2005 17:20 GMT

Hello,

EG> You missed [vararg] in the function declaration.

Uh, sorry, did not notice it as it was on another line.

EG> In any case I tried your suggestion
EG>
EG> var doc = new ActiveXObject("htmlfile");
EG> doc.write(["abc"]);
EG> and got exactly the same error as before.

And what if you pass a strongly-typed argument?

(H) Serg

Reply to this Message

Eugene Gershnik - 18 Oct 2005 06:52 GMT

>> In any case I tried your suggestion
>>
[quoted text clipped - 3 lines]
>
> And what if you pass a strongly-typed argument?

I tried:

1)

import System;

var doc = new ActiveXObject("htmlfile");
var x : System.String = "abc"
doc.write(x);

2)

import System;

var doc = new ActiveXObject("htmlfile");
var x : System.String = "abc"
doc.write([x]);

3)

import System;

var doc = new ActiveXObject("htmlfile");
var x : System.String[] = new System.String[1];
x[0] = "abc"
doc.write(x);

4)

import System;

var doc = new ActiveXObject("htmlfile");
var x : System.String[] = new System.String[1];
x[0] = "abc"
var y : System.Object[] = x;
doc.write(y);

All with the same result.

Unhandled Exception: System.Runtime.InteropServices.COMException
(0x80020005): T
ype mismatch.

at System.RuntimeType.ForwardCallToInvokeMember(String memberName,
BindingFla
gs flags, Object target, Int32[] aWrapperTypes, MessageData& msgData)
at mshtml.HTMLDocumentClass.write(Object[] psarray)
....

Assuming mshtml.HTMLDocumentClass is not broken it appears that JScript.NET
is :-(

--
Eugene

Reply to this Message

Bruce Barker - 19 Oct 2005 17:27 GMT

getting .net to work with com is always difficult. javascript.net tries
harder than most other .net languages, but still falls short. you should use
the mshtml interop assembly (comes with 1.1), rather than having
javascript.net dynamically try to figure out what to pass.

-- bruce (sqlwork.com)

>>> In any case I tried your suggestion
>>>
[quoted text clipped - 58 lines]
> --
> Eugene

Reply to this Message

Eugene Gershnik - 19 Oct 2005 18:04 GMT

> getting .net to work with com is always difficult. javascript.net
> tries harder than most other .net languages, but still falls short.
> you should use the mshtml interop assembly (comes with 1.1), rather
> than having javascript.net dynamically try to figure out what to pass.

But I *am* using it! Look at the top error stack from the original post

...
at mshtml.HTMLDocumentClass.write(Object[] psarray)
...

.NET automatically substitutes mshtml for the COM component probably because
of the following entries under InprocServer32 in registry (also mentioned in
more detail in one of the previous posts)

Assembly REG_SZ Microsoft.mshtml, Version=7.0.3300.0, Culture=neutral,
PublicKeyToken=b03f5f7f11d50a3a
Class REG_SZ mshtml.HTMLDocumentClass
RuntimeVersion REG_SZ v1.0.3705

It looks like whatever JScript.NET passes to mshtml is broken.

Signature

Eugene
http://www.gershnik.com

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Bruce Barker - 21 Oct 2005 21:37 GMT

all languages have trouble calling this componenet. the actual com component
is expecting a a safearray of olevariants. the interop is expecting a parm
array of objects that can be convert to an olevariants (of type string).

try using a typed variable, so that javascript.net does not have to guess
the datatype for the interop assembly.

var s : string = "abc";
doc.write(s);

or

doc.write(String("abc"));

-- bruce (sqlwork.com)

>> getting .net to work with com is always difficult. javascript.net
>> tries harder than most other .net languages, but still falls short.
[quoted text clipped - 17 lines]
>
> It looks like whatever JScript.NET passes to mshtml is broken.

Reply to this Message

Eugene Gershnik - 22 Oct 2005 06:01 GMT

> all languages have trouble calling this componenet. the actual com
> component is expecting a a safearray of olevariants. the interop is
> expecting a parm array of objects that can be convert to an
> olevariants (of type string).

Yes the following C# code has the same problem

using mshtml;
...
HTMLDocumentClass doc = new HTMLDocumentClass();
doc.write("abc");

> try using a typed variable, so that javascript.net does not have to
> guess the datatype for the interop assembly.

If you look a few messages above in this thread you'll see that I already
tried that (as well as other possible combinations) and it didn't work.
Trying the same combinations in C# produced the same exception.

So it looks like mshtml wrapper is broken.

Signature

Eugene

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ActiveXObject("htmlfile") and Jscript.NET

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