Returning data from VC++ ASP component

[Zohar Nissare-Houssen]

Hello,

I have to write an ASP Component in VC++ who returns multiple variables.

What is the easiest way to return for example 3 variables from the
VC++ component to an ASP page written in VBScript ?

- Can I do it using OUT parameters in the methods ; If so, how can I do it
in my C++ method using OLE
Automation ? And how can I code it in my ASP page using VBScript ?

- If not, what is the easiest way to return these parameters ? Where can
I find an easy sample of it ?


Any help would be much appreciated.

Thank you very much

Zohar Nissare-Houssen
TravelNet Technologies

[Scott Mitchell]

Hello Zohar. I have very little experience with creating COM components via
VC++. I've only done this once just to see if I could! :-) You can read
about my attempts at: http://www.4guysfromrolla.com/webtech/052600-1.shtml

I'd also HIGHLY recommend that you join this ListServ: http://www.asplists.com/asplists/asp...components.asp

Ask your questions there and you'll get great responses from seasoned pros...

Happy Programming!

Scott Mitchell
mitchell@4guysfromrolla.com
http://www.4GuysFromRolla.com
http://www.ASPMessageBoard.com
http://www.ASPFAQs.com

* When you think ASP, think 4GuysFromRolla.com!

"Zohar Nissare-Houssen" <znissare@travelnet.ca> wrote:
>
>Hello,
>
>I have to write an ASP Component in VC++ who returns multiple variables.
>
>What is the easiest way to return for example 3 variables from the
>VC++ component to an ASP page written in VBScript ?
>
>- Can I do it using OUT parameters in the methods ; If so, how can I do
it
>in my C++ method using OLE
>Automation ? And how can I code it in my ASP page using VBScript ?
>
>- If not, what is the easiest way to return these parameters ? Where can
>I find an easy sample of it ?
>
>
>Any help would be much appreciated.
>
>Thank you very much
>
>Zohar Nissare-Houssen
>TravelNet Technologies
>

[Zohar Nissare-Houssen]

Hello Scott,

Thank you very much for your help. The ListServ link you gave me will be
very useful...
But I have another question related this time to VBScript language coding
in ASP
still related to my problem :-)

I finally wrote a component method who returns an array of variant. Let's
say that this method is called
ReturnArray and takes two IN parameters, I coded the following in my ASP
page :

<%set MyObject=Server.CreateObject("ASPCOMPONENT.MYOBJECT")%>
...
Dim foo(3) [or Dim foo()]
foo = MyObject.ReturnArray(v1,v2)

This code causes a type mismatch error.

IsArray( MyObject.ReturnArray(v1,v2) ) returns TRUE
VarType( MyObject.ReturnArray(v1,v2) ) returns 8192 (vbArray constant)

So my return type is recognised as an array by VBScript but I can't pass
it directly into an array variable. I coded then a
VBScript procedure copying two arrays, element by element : Sub CopyArray(array_dest,array_origin,nbelements).
I use it like that

Dim foo(3)
CopyArray foo, MyObject.ReturnArray(v1,v2), 3

This code also causes a type mismatch error on array_origin

Then, I wrote another method in VC++ returning an element of an array. Let's
say this method is
ReturnArrayElem(Array,position)

In my ASP page this code works :

foo0 = MyObject.ReturnArrayElem( MyObject.ReturnArray(v1,v2) , 0 )
foo1 = MyObject.ReturnArrayElem( MyObject.ReturnArray(v1,v2) , 1 )
...

But the problem is that all the array is processed each time I need an element...

So, my question is : How can I stock the array resulting from a method call
in VBscript ? Is it possible ?

Any idea would be much appreciated.

Thank you

Zohar Nissare-Houssen
TravelNet Technologies





"Scott Mitchell" <mitchell@4guysfromrolla.com> wrote:
>
>Hello Zohar. I have very little experience with creating COM components
via
>VC++. I've only done this once just to see if I could! :-) You can read
>about my attempts at: http://www.4guysfromrolla.com/webtech/052600-1.shtml
>
>I'd also HIGHLY recommend that you join this ListServ: http://www.asplists.com/asplists/asp...components.asp
>
>Ask your questions there and you'll get great responses from seasoned pros...
>
>Happy Programming!
>
> Scott Mitchell
> mitchell@4guysfromrolla.com
> http://www.4GuysFromRolla.com
> http://www.ASPMessageBoard.com
> http://www.ASPFAQs.com
>
>* When you think ASP, think 4GuysFromRolla.com!
>
>"Zohar Nissare-Houssen" <znissare@travelnet.ca> wrote:
>>
>>Hello,
>>
>>I have to write an ASP Component in VC++ who returns multiple variables.
>>
>>What is the easiest way to return for example 3 variables from the
>>VC++ component to an ASP page written in VBScript ?
>>
>>- Can I do it using OUT parameters in the methods ; If so, how can I do
>it
>>in my C++ method using OLE
>>Automation ? And how can I code it in my ASP page using VBScript ?
>>
>>- If not, what is the easiest way to return these parameters ? Where can
>>I find an easy sample of it ?
>>
>>
>>Any help would be much appreciated.
>>
>>Thank you very much
>>
>>Zohar Nissare-Houssen
>>TravelNet Technologies
>>
>

[Scott Mitchell]

Have you tried:
Dim foo
foo = MyObject.ReturnArray(v1,v2)

???

"Zohar Nissare-Houssen" <znissare@travelnet.ca> wrote:
>
>Hello Scott,
>
>Thank you very much for your help. The ListServ link you gave me will be
>very useful...
>But I have another question related this time to VBScript language coding
>in ASP
>still related to my problem :-)
>
>I finally wrote a component method who returns an array of variant. Let's
>say that this method is called
>ReturnArray and takes two IN parameters, I coded the following in my ASP
>page :
>
><%set MyObject=Server.CreateObject("ASPCOMPONENT.MYOBJECT")%>
>...
>Dim foo(3) [or Dim foo()]
>foo = MyObject.ReturnArray(v1,v2)
>
>This code causes a type mismatch error.
>
>IsArray( MyObject.ReturnArray(v1,v2) ) returns TRUE
>VarType( MyObject.ReturnArray(v1,v2) ) returns 8192 (vbArray constant)
>
>So my return type is recognised as an array by VBScript but I can't pass
>it directly into an array variable. I coded then a
>VBScript procedure copying two arrays, element by element : Sub CopyArray(array_dest,array_origin,nbelements).
>I use it like that
>
>Dim foo(3)
>CopyArray foo, MyObject.ReturnArray(v1,v2), 3
>
>This code also causes a type mismatch error on array_origin
>
>Then, I wrote another method in VC++ returning an element of an array. Let's
>say this method is
>ReturnArrayElem(Array,position)
>
>In my ASP page this code works :
>
>foo0 = MyObject.ReturnArrayElem( MyObject.ReturnArray(v1,v2) , 0 )
>foo1 = MyObject.ReturnArrayElem( MyObject.ReturnArray(v1,v2) , 1 )
>...
>
>But the problem is that all the array is processed each time I need an element...
>
>So, my question is : How can I stock the array resulting from a method
call
>in VBscript ? Is it possible ?
>
>Any idea would be much appreciated.
>
>Thank you
>
>Zohar Nissare-Houssen
>TravelNet Technologies
>
>
>
>
>
>"Scott Mitchell" <mitchell@4guysfromrolla.com> wrote:
>>
>>Hello Zohar. I have very little experience with creating COM components
>via
>>VC++. I've only done this once just to see if I could! :-) You can read
>>about my attempts at: http://www.4guysfromrolla.com/webtech/052600-1.shtml
>>
>>I'd also HIGHLY recommend that you join this ListServ: http://www.asplists.com/asplists/asp...components.asp
>>
>>Ask your questions there and you'll get great responses from seasoned pros...
>>
>>Happy Programming!
>>
>> Scott Mitchell
>> mitchell@4guysfromrolla.com
>> http://www.4GuysFromRolla.com
>> http://www.ASPMessageBoard.com
>> http://www.ASPFAQs.com
>>
>>* When you think ASP, think 4GuysFromRolla.com!
>>
>>"Zohar Nissare-Houssen" <znissare@travelnet.ca> wrote:
>>>
>>>Hello,
>>>
>>>I have to write an ASP Component in VC++ who returns multiple variables.
>>>
>>>What is the easiest way to return for example 3 variables from the
>>>VC++ component to an ASP page written in VBScript ?
>>>
>>>- Can I do it using OUT parameters in the methods ; If so, how can I do
>>it
>>>in my C++ method using OLE
>>>Automation ? And how can I code it in my ASP page using VBScript ?
>>>
>>>- If not, what is the easiest way to return these parameters ? Where can
>>>I find an easy sample of it ?
>>>
>>>
>>>Any help would be much appreciated.
>>>
>>>Thank you very much
>>>
>>>Zohar Nissare-Houssen
>>>TravelNet Technologies
>>>
>>
>

[Zohar Nissare-Houssen]

Hi Scott,

I finally solved my problem. It was not a VBScript problem. The problem was
on the Array type returned
by my component method.

From VBScript, the good hint that helped me was that :

VarType( MyObject.ReturnArray(v1,v2) ) returns 8192 (vbArray constant)

And, In fact, I learned that you can never get VarType of only 8192 - it
always has to be an array of
something (And as return result from COM objects, VBScript only supports
ARRAY of VARIANTS)

So, I should have get the following value for an array of nb=2 elements :

8204 = 1* (vbArray=8192) + (nb-1)*(vbVariant=12)

Another VBScript function is also very useful : TypeName(MyObject.ReturnArray(v1,v2))
to check
return array from COM VB/VC Component. It should always return string "Variant()"
for an
array of variant.

Zohar

"Scott Mitchell" <mitchell@4guysfromrolla.com> wrote:
>
>Have you tried:
>Dim foo
>foo = MyObject.ReturnArray(v1,v2)
>
>???
>
>"Zohar Nissare-Houssen" <znissare@travelnet.ca> wrote:
>>
>>Hello Scott,
>>
>>Thank you very much for your help. The ListServ link you gave me will be
>>very useful...
>>But I have another question related this time to VBScript language coding
>>in ASP
>>still related to my problem :-)
>>
>>I finally wrote a component method who returns an array of variant. Let's
>>say that this method is called
>>ReturnArray and takes two IN parameters, I coded the following in my ASP
>>page :
>>
>><%set MyObject=Server.CreateObject("ASPCOMPONENT.MYOBJECT")%>
>>...
>>Dim foo(3) [or Dim foo()]
>>foo = MyObject.ReturnArray(v1,v2)
>>
>>This code causes a type mismatch error.
>>
>>IsArray( MyObject.ReturnArray(v1,v2) ) returns TRUE
>>VarType( MyObject.ReturnArray(v1,v2) ) returns 8192 (vbArray constant)
>>
>>So my return type is recognised as an array by VBScript but I can't pass
>>it directly into an array variable. I coded then a
>>VBScript procedure copying two arrays, element by element : Sub CopyArray(array_dest,array_origin,nbelements).
>>I use it like that
>>
>>Dim foo(3)
>>CopyArray foo, MyObject.ReturnArray(v1,v2), 3
>>
>>This code also causes a type mismatch error on array_origin
>>
>>Then, I wrote another method in VC++ returning an element of an array.
Let's
>>say this method is
>>ReturnArrayElem(Array,position)
>>
>>In my ASP page this code works :
>>
>>foo0 = MyObject.ReturnArrayElem( MyObject.ReturnArray(v1,v2) , 0 )
>>foo1 = MyObject.ReturnArrayElem( MyObject.ReturnArray(v1,v2) , 1 )
>>...
>>
>>But the problem is that all the array is processed each time I need an
element...
>>
>>So, my question is : How can I stock the array resulting from a method
>call
>>in VBscript ? Is it possible ?
>>
>>Any idea would be much appreciated.
>>
>>Thank you
>>
>>Zohar Nissare-Houssen
>>TravelNet Technologies
>>
>>
>>
>>
>>
>>"Scott Mitchell" <mitchell@4guysfromrolla.com> wrote:
>>>
>>>Hello Zohar. I have very little experience with creating COM components
>>via
>>>VC++. I've only done this once just to see if I could! :-) You can
read
>>>about my attempts at: http://www.4guysfromrolla.com/webtech/052600-1.shtml
>>>
>>>I'd also HIGHLY recommend that you join this ListServ: http://www.asplists.com/asplists/asp...components.asp
>>>
>>>Ask your questions there and you'll get great responses from seasoned
pros...
>>>
>>>Happy Programming!
>>>
>>> Scott Mitchell
>>> mitchell@4guysfromrolla.com
>>> http://www.4GuysFromRolla.com
>>> http://www.ASPMessageBoard.com
>>> http://www.ASPFAQs.com
>>>
>>>* When you think ASP, think 4GuysFromRolla.com!
>>>
>>>"Zohar Nissare-Houssen" <znissare@travelnet.ca> wrote:
>>>>
>>>>Hello,
>>>>
>>>>I have to write an ASP Component in VC++ who returns multiple variables.
>>>>
>>>>What is the easiest way to return for example 3 variables from the
>>>>VC++ component to an ASP page written in VBScript ?
>>>>
>>>>- Can I do it using OUT parameters in the methods ; If so, how can I
do
>>>it
>>>>in my C++ method using OLE
>>>>Automation ? And how can I code it in my ASP page using VBScript ?
>>>>
>>>>- If not, what is the easiest way to return these parameters ? Where
can
>>>>I find an easy sample of it ?
>>>>
>>>>
>>>>Any help would be much appreciated.
>>>>
>>>>Thank you very much
>>>>
>>>>Zohar Nissare-Houssen
>>>>TravelNet Technologies
>>>>
>>>
>>
>