circular reference problem

[dotnetnewbie]

Hi all

I am new to .NET and webservice so I wish someone can shed some light
on me.

I have a Project class and a Product class, the Project can contain
multiple Products (as an ArrayList). In my WebMethod I Initialize my
project as following:
<WebMethod()> Public Function ProjectInitial( )
As Project

'Public Function ProjectInitial( ByVal inputProduct As
Product) As Project
Dim myProject As New Project
myProject = InitialProject( "Test Project")

Dim myProduct As New Product
myProduct.cost = 100
myProduct.maste rQty = 1000

Dim myProduct2 As New Product
myProduct2.cost = 200
myProduct2.mast erQty = 2000
myProject.AddFi nishProduct(myP roduct)
myProject.AddFi nishProduct(myP roduct2)

Return myProject
End Function
The following is the structure of my Project class

[code:1:bb159c48 1b]

Imports System.Xml.Seri alization

<XmlInclude(Get Type(Product))> Public Class
Project

#Region " Project Properties "

Public projectID As Int32
Public projectName As String
Public projectStatus As Int32
Public projectCreateDa te As DateTime
Public projectModifyDa te As DateTime

Public ProductList As New ArrayList

#End Region

Public Sub AddFinishProduc t(ByVal inputProduct As
Product)
'Add Product into the arraylist "ProductLis t "
....
....
End Sub
End Class
[/code:1:bb159c48 1b]

The following is the structure of my Product class

[code:1:bb159c48 1b]

Imports System.Xml.Seri alization

<XmlInclude(Get Type(Properties )),
SoapInclude(Get Type(Product))> Public Class
Product
' Product properties
Public masterQty As Int32
Public cost As Double ' temperary cost, will use config costs to
replace
Public PropertyList As New ArrayList

' ArrayList stores it's component product
Public componentProduc t As New ArrayList

Public Sub AddProduct(ByVa l inputProduct As Product)
'Add Product object into componentProduc t
....
....
End Sub
End Class
[/code:1:bb159c48 1b]

As you can see the I wish the Product can also contain a list of
Products because in my logic some Product can be constructed by a
list of Component Product but I want them to be in the same structure
because they have the same properties, also a Component Product can be
constructed by other Component Product.

If I don't add Product object into the Product, every
thing goes ok. But if I add a Project object inside a Product I have
the following error message

System.InvalidO perationExcepti on: There was an error
generating the XML document. --->
System.InvalidO perationExcepti on: A circular reference was detected
while serializing an object of type
ProjectInitiali ze.Product.

Is there any work around I can do to solve the problem? :?

Thanks in advance for your tips

[Benjamin Day]

Has anyone found a solution to this web service circular reference problem?

Here's a simplified example:

Person him=new Person();
Person her=new Person();

him.Friend=her;
her.Friend=him;

Now try to serialize one of those object through an ASMX web service and
you'll get the following:

System.InvalidO perationExcepti on: There was an error generating the XML
document. --->
System.InvalidO perationExcepti on: A circular reference was detected while
serializing an object of type Person.

This article on IBM's site implies that .NET can do this somehow:
http://www-106.ibm.com/developerwork...-tip-j2eenet1/

Any ideas?

-Ben
http://www.benday.com

"dotnetnewb ie" wrote:

Hi all

I am new to .NET and webservice so I wish someone can shed some light
on me.

I have a Project class and a Product class, the Project can contain
multiple Products (as an ArrayList). In my WebMethod I Initialize my
project as following:
<WebMethod()> Public Function ProjectInitial( )
As Project

'Public Function ProjectInitial( ByVal inputProduct As
Product) As Project
Dim myProject As New Project
myProject = InitialProject( "Test Project")

Dim myProduct As New Product
myProduct.cost = 100
myProduct.maste rQty = 1000

Dim myProduct2 As New Product
myProduct2.cost = 200
myProduct2.mast erQty = 2000
myProject.AddFi nishProduct(myP roduct)
myProject.AddFi nishProduct(myP roduct2)

Return myProject
End Function
The following is the structure of my Project class

[code:1:bb159c48 1b]

Imports System.Xml.Seri alization

<XmlInclude(Get Type(Product))> Public Class
Project

#Region " Project Properties "

Public projectID As Int32
Public projectName As String
Public projectStatus As Int32
Public projectCreateDa te As DateTime
Public projectModifyDa te As DateTime

Public ProductList As New ArrayList

#End Region

Public Sub AddFinishProduc t(ByVal inputProduct As
Product)
'Add Product into the arraylist "ProductLis t "
....
....
End Sub
End Class
[/code:1:bb159c48 1b]

The following is the structure of my Product class

[code:1:bb159c48 1b]

Imports System.Xml.Seri alization

<XmlInclude(Get Type(Properties )),
SoapInclude(Get Type(Product))> Public Class
Product
' Product properties
Public masterQty As Int32
Public cost As Double ' temperary cost, will use config costs to
replace
Public PropertyList As New ArrayList

' ArrayList stores it's component product
Public componentProduc t As New ArrayList

Public Sub AddProduct(ByVa l inputProduct As Product)
'Add Product object into componentProduc t
....
....
End Sub
End Class
[/code:1:bb159c48 1b]

As you can see the I wish the Product can also contain a list of
Products because in my logic some Product can be constructed by a
list of Component Product but I want them to be in the same structure
because they have the same properties, also a Component Product can be
constructed by other Component Product.

If I don't add Product object into the Product, every
thing goes ok. But if I add a Project object inside a Product I have
the following error message

System.InvalidO perationExcepti on: There was an error
generating the XML document. --->
System.InvalidO perationExcepti on: A circular reference was detected
while serializing an object of type
ProjectInitiali ze.Product.

Is there any work around I can do to solve the problem? :?

Thanks in advance for your tips